News & Research

By Reuters Staff
July 29, 2015

NEW YORK (Reuters Health) – Four in 10 patients with celiac disease (CD) have abnormal liver function tests (LFTs) at diagnosis, but they generally normalize with treatment, new findings show.

CD is known to be associated with several disorders of the liver, according to Dr. Daniel Leffler of Beth Israel Deaconess Medical Center in Boston and colleagues.

Up to half of adults and children with CD have elevated LFTs when they are diagnosed, the researchers note. Guidelines call for LFTs at diagnosis and then annually.

“However, not all recent studies have shown this high prevalence of LFT abnormalities in CD patients, casting some doubt on the need for routine liver evaluation in this population,” Dr. Leffler and his team wrote.

To investigate the prevalence of abnormal LFTs in U.S. CD patients, and the effect of a gluten-free diet on LFTs, the researchers looked at data on 463 adults with biopsy-confirmed celiac disease and matched controls, plus 7789 people participating in the 2009-2010 National Health and Nutrition Examination Survey (NHANES).

As reported online July 7 in the American Journal of Gastroenterology, aminotransferase levels were significantly higher in the celiac patients (ALT, 36.7 vs. 26.4IU/L and AST, 34.3 vs. 25.8IU/l, P<0.001 for both). Before treatment, 40.6% of the CD patients had elevated LFTs, compared with 16.6% of matched controls. In the NHANES cohort, 36.7% of people with CD had abnormal LFTs, versus 19.3% of those without CD. Among patients who followed a gluten-free diet for a mean of 1.5 years, nearly 80% (132/168) of those with abnormal LFTs at diagnosis had normalized. When follow-up was extended to an average of nearly four years, however, only about 60% (100/168) had persistently normal liver function. “These data support the screening for LFT abnormalities in all newly diagnosed CD individuals,” Dr. Leffler and his team wrote. “Strict adherence to a (gluten-free diet) can reduce LFT abnormalities within a year and patients with sustained LFT abnormalities despite a (gluten-free diet) should be evaluated for coexisting liver diseases. A ‘treat-first then re-evaluate’ approach should be initially considered by clinicians instead of initial, extensive investigation for chronic liver disorders.” SOURCE: http://bit.ly/1HYiO8x Am J Gastroenterol 2015.

Dominica Gidrewicz MD, MSc; Kathryn Potter MD, PhD; Cynthia L. Trevenen MD; Martha Lyon MSc; PhD; J. Decker Butzner MD
Disclosures
Am J Gastroenterol. 2015;110(5):760-767. 

bstract and Introduction

Abstract
Objectives We retrospectively examined the performance of the tissue transglutaminase (TTG), endomysial antibody (EMA) tests, and the ESPGHAN (European Society of Paediatric Gastroenterology, Hepatology and Nutrition) nonbiopsy criteria in a pediatric population.

Methods Consecutive celiac serologies and corresponding intestinal biopsy results were obtained on children <18 years old over 3.5 years. Patients were classified into three categories: positive TTG, negative TTG, and IgA deficiency. Results Of the 17,505 patients with celiac serology performed, 775 had a positive TTG, 574 with a negative TTG were biopsied, and 25 were IgA deficient. Of the patients with a TTG ≥10 × upper limit of normal (ULN), positive EMA, and symptoms, 98.2% had biopsies consistent with celiac disease (CD). Four human leukocyte antigen (HLA) DQ2/DQ8-positive patients who met the ESPGHAN nonbiopsy criteria did not have CD. In the group with a TTG 3–10 × ULN, 75.7% EMA-positive patients and only 40% EMA-negative patients had CD (P<0.001). Of those with a TTG 1–3 × ULN, 52.2% EMA-positive patients vs. only 13.3% EMA-negative patients had CD (P<0.01). Of the patients with bulbar and duodenal biopsies, 9.8% had CD confined only in the bulb, especially those with a low titer TTG (P<0.01). CD prevalence in our cohort was 34.6%. Sensitivity, specificity, and positive predictive value of the TTG were 98.7%, 86.4%, and 79.4%, respectively. Conclusions The TTG is a very sensitive screen for CD, but positive predictive value improves with a positive EMA titer. To apply the new ESPGHAN guidelines, clinicians must understand the performance of their celiac serology tests.

Introduction
Children require a timely and accurate diagnosis of celiac disease (CD). Achievement of this is challenging because of variable clinical disease presentations.[1] Many children and families are stressed by the endoscopy that is time-consuming and costly. The development of accurate serologic testing for CD, however, has advanced the management of this disease. Previously, every pediatric patient received advice to undergo an upper endoscopy to obtain distal duodenal biopsies to definitively establish a histological diagnosis of CD. New pediatric guidelines published by the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) outline the criteria under which a nonbiopsy diagnosis of CD can be made.[2] These specific requirements include a symptomatic patient with a tissue transglutaminase (TTG) ≥10 × upper limit of normal (ULN), a positive endomysial antibody (EMA; collected on a second blood sample) and a positive human leukocyte antigen (HLA) DQ2 and/or DQ8 status, agreement by the family, and response to a gluten-free diet (GFD). In addition, a cohort of children who are asymptomatic with a TTG <3 × ULN can be followed to evaluate the trend in serological testing rather than undergoing an intestinal biopsy. In translating clinical guidelines into daily routine practice, evaluating them in cohorts of patients against the gold standard, serology followed by intestinal biopsy was recommended by the ESPGHAN guideline committee. When performing endoscopy, the new guidelines recommend at least four biopsies from the second or the third portion of the duodenum plus at least one biopsy from the duodenal bulb because CD duodenal biopsy abnormalities may be patchy.[2] Data in both adult and pediatric patients demonstrated that up to 11% of patients displayed findings diagnostic of CD confined to the duodenal bulb.[3–6] Current guidelines recommend that all patients receive both bulbar and descending duodenal biopsies. Data are lacking to evaluate whether a subgroup of patients with specified celiac serology results can be identified who do not require the additional time and cost of duodenal bulbar biopsies. The aim of our study was to test the performance of the ESPGHAN guidelines for the nonbiopsy diagnosis of CD in a pediatric gastroenterology clinic that provides the only service to a large pediatric population of over 150,000 children. We also investigated the additional utility of EMA testing to predict the likelihood of biopsy-proven celiac disease. Finally, we explored the utility of duodenal bulb biopsies to determine whether they can be limited to a subgroup of patients. Methods

Case Identification and Data Collection
Consecutive patients (<18 years of age) with celiac serology displayed in the Calgary Laboratory Services database from July 2008 to December 2011 were identified. All patients had a serum IgA (Roche Diagnostics, Laval, Quebec, Canada) and IgA TTG performed (Euroimmune, Lubeck, Germany). If the TTG was positive (>20 kU/l), an IgA antiendomysial antibody test was measured. Experienced technicians tested samples for EMA by an indirect immunofluorescence method from a commercial test system using monkey distal esophagus as substrate (IMMCO Diagnostics, Buffalo, NY). Positive samples were serially diluted from titers of 1:2.5 to 1:1,280, and a titer of 1:2.5 was considered to be the threshold for positivity, as established by the manufacturer. IgA deficiency was defined as serum IgA <0.1 g/l in patients ≥2 years of age. Patients with an IgA of ≤0.1 g/l had an IgG TTG (Euroimmune) determined. HLA DQ2/DQ8 testing was performed on patients by physician preference. Intestinal biopsy results were obtained on patients, with positive or negative celiac serology results, from the Alberta Children's Hospital Pathology Database from July 2008 to April 2012. Biopsy results were used if the TTG was measured within 6 months before the biopsy. This hospital is the only pediatric gastroenterology referral center in southern Alberta and is staffed by nine pediatric gastroenterologists who perform endoscopies. Duodenal biopsies were reviewed by one pathologist (C.L.T.) and a modified Marsh score was assigned.[7] Children had 4–5 duodenal biopsies, and from 2009 an additional 1–2 duodenal bulb biopsies were performed. The data were generated on the TTG collected closest to the time of the intestinal biopsy, and data were reviewed carefully to remove duplicate or subsequent measurements on a patient. The following exclusion criteria were applied to patients with positive celiac serology: blood work and/or biopsies performed outside the defined study period times; no duodenal biopsies performed; celiac serology not measured by Calgary Laboratory Services; or no history or biopsy data could be retrieved (n=12). Patients with negative celiac serology whose biopsy was performed >6 months from the time of the negative serology were also excluded.

The clinic charts and small-bowel pathology reports were reviewed, and data on the following parameters were extracted: (i) clinical information, including patient demographics, presenting symptoms and dietary history (gluten intake), CD-associated condition(s) (e.g., family history of CD in a first-degree relative, type 1 diabetes mellitus, thyroiditis, trisomy 21), date of biopsy; (ii) HLA DQ2/8 results (if available); (iii) small-intestinal biopsy results at diagnosis (divided into duodenal cap and descending duodenum, if applicable), including the modified Marsh score; and (iv) response to a GFD. A group of 176 patients with a positive TTG had no record of intestinal biopsy or consultation with a pediatric gastroenterologist. A questionnaire was mailed to the TTG ordering physician to evaluate the management of these TTG-positive patients.

Data Analyses
Patients were classified initially into groups according to the TTG recorded closest to the time of biopsy: TTG ≥10 × ULN (≥200 kU/l), TTG 3–10 × ULN (60–199 kU/l), TTG 1–3 × ULN (20–59 kU/l), negative TTG (<20 kU/l), and IgA-deficient patients. If applicable, each group was then subdivided into categories: biopsy diagnostic of celiac disease, normal or other diagnosis on intestinal biopsy, patients with known CD undergoing follow-up testing, patients who refused endoscopy seen by a pediatric gastroenterologist, and patients not referred to the pediatric gastroenterology clinic at the Alberta Children's Hospital. Statistics
Where appropriate, median, mean, and 95% confidence intervals (CIs) were calculated. The significance of the difference between two independent proportions was calculated using a two-tailed t-test of proportions. Odds ratios (ORs) and the 95% CIs were calculated. P values <0.05 are considered significant. This study was approved by the University of Calgary Conjoint Health Research Ethics Boards. Results
Study Patients
Of the 17,505 patients <18 years of age who had celiac serology performed during the study period, 817 had a positive celiac serology (≥20 kU/l) (4.6%; 95% CI 4.3–5.0%; Figure 1). Forty-two patients were excluded for the following reasons: inadequate biopsy report (n=9), biopsies performed outside study period (n=8), and serology performed >6 months from the time of biopsy (n=25). Of the 738 patients who had a negative TTG (<20 kU/l) and a negative intestinal biopsy, 164 were excluded as serology was performed >6 months from the time of biopsy. Analyses were performed on the 775 TTG-positive and 574 TTG-negative IgA-sufficient patients (Figure 1), as well as 25 IgA-deficient patients who met the study inclusion criteria.

Figure 1.
All patients with tissue transglutaminase (TTG) done during the study period. CD, celiac disease; EMA, endomysial antibody; ULN, upper limit of normal.

The 775 TTG-positive patients were stratified into three groups according to the TTG level: group A, TTG ≥10 × ULN (≥200 kU/l); group B, TTG 3–10 × ULN (60–199 kU/l); and group C, TTG 1–3 × ULN (20–59 kU/l) (Figure 1). Of these, 437 (56%; 95% CI 53–59%) patients underwent intestinal biopsy at a mean age of 10.2 years (1.0–18 years), and 62.5% (95% CI 58–67%) were female. A varying proportion of patients with a positive TTG in each of the three groups (A–C) did not undergo a biopsy for the following reasons: known CD (n=56), patients were not referred to pediatric gastroenterologist (n=176), and patients were seen but not biopsied (n=106). Of the last group, a biopsy was not performed for the following reasons: family refused biopsy because they previously started on a GFD (n=26), endoscopy recommended by pediatric gastroenterologist but family refused (n=6), repeat serology normalized (n=21), biopsies outside the study period led to diagnosis of CD (n=4), and pediatric gastroenterologist decided against biopsy (n=49; e.g., negative HLA DQ2/8, symptoms resolved before consultation, false-positive serology from intercurrent illness, or other autoimmune condition). All symptomatic patients diagnosed with CD reported that they responded to a GFD at their 1-year follow-up evaluation.

A fourth group (group D) of 574 patients who underwent intestinal biopsies had negative TTGs. Of these, three had biopsies diagnostic of CD (one patient was DQ2 positive), and all three responded to a GFD (Figure 1). The remainder 571 patients had negative biopsies with a mean age at endoscopy of 10.6 years, range 0.8–18 years, and 48.3% female (Table 1).

TTG ≥10 × ULN (Group A)
A TTG ≥10 × ULN was observed in 336 patients (43.4%; 95% CI 40–47%, group A, Figure 1), including 270 who underwent an intestinal biopsy and 66 (19.6%; 95% CI 16–24%) who were not biopsied for the following reasons: follow-up serology of known CD (n=12), not referred (n=31), and refused biopsy (n=23, of which 16 already started a GFD). Of the 270 patients who had an intestinal biopsy, 263 had a positive EMA (97.4%; 95% CI 95–99%) and 7 had a negative EMA. CD was diagnosed on biopsy in 256 EMA-positive patients (97.3%; 95% CI 95–99%) and 3 EMA-negative patients (42.9%; 95% CI 16–75%) (OR=48.8; 95% CI 9–260%, P<0.001, Table 3). A group of 8 symptomatic patients with TTG ≥10 ULN had biopsies not diagnostic of CD. Four patients were EMA positive (highest titer 1:40), and all were either HLA DQ2 and/or DQ8 positive (Table 2). On follow-up, one patient developed type 1 diabetes mellitus 2 years later and repeat biopsies diagnosed CD, Marsh 3B. A second patient had repeat biopsies 2 years later that were negative for CD. The other two patients' health and antibody levels improved on a gluten-containing diet and decided not to undergo repeat endoscopy. Four patients were EMA negative, of which three had normalization of the TTG 2–5 months after endoscopy while continuing on a gluten-containing diet. Two had a recent gastrointestinal infection at the time of initial screening, and one patient who was HLA DQ2/8 negative was lost to follow-up. Of the 270 patients with a TTG ≥10 × ULN and intestinal biopsy, 91 (33.8%; 95% CI 28–40%) had a CD-associated condition. The majority of these (88 patients) had biopsies diagnostic of CD (96.7%; 95% CI 91–99%) (Supplementary Table S1 online http://www.nature.com/ajg/journal/v110/n5/suppinfo/ajg201587s1.html). Of these 43 (48.9%; 95% CI 39–59%) were asymptomatic at the time of celiac screening. Only 3 (7%; 95% CI 2–18%) patients with high TTGs and an associated condition had biopsies not diagnostic of CD, with the highest EMA titer being 1:40. Two of these had type 1 diabetes mellitus and one had Grave's disease with a family history of CD. In one patient, TTG and EMA remained elevated and 18 months later repeat biopsy confirmed CD, Marsh 3C. The others continue to be followed. TTG 3–10 × ULN (Group B)
Of the 775 patients with a positive TTG, 194 (25.0%; 95% CI 22–28%) had a TTG between 3 and 10 × ULN (Figure 1, group B). In group B, 114 (58.8%; 95% CI 52–65%) had an intestinal biopsy, whereas 80 patients (41.2%; 95% CI 34–48%) did not undergo biopsy for the following reasons: follow-up serology of known CD (n=25), not referred (n=38), and refused biopsy (n=17). Of the 114 patients who underwent intestinal biopsy, 74 were EMA positive (64.9%; 95% CI 56–73%) and 40 were EMA negative. Biopsies were diagnostic of CD in 56 EMA-positive patients (75.7%; 95% CI 65–84%) and 16 EMA-negative patients (40%; 95% CI 26–55%) (OR=4.7; 95% CI 2.0–10.7%, P<0.001, Table 3). In group B, 45 (23.2%; 95% CI 18–30%) of the 194 patients had a CD-associated condition and underwent an intestinal biopsy. Biopsies were diagnostic of CD in 28 of these patients (62.2%; 95% CI 48–75%), and 14 (50%; 95% CI 33–67%) were asymptomatic at the time of celiac screening. TTG 1–3 × ULN (Group C)
Of the 775 patients with a positive TTG, 245 (31.6%; 95% CI 28–35%) had a TTG 1–3 × ULN (Figure 1, group C). Within this group, 53 (21.6%; 95% CI 17–27%) had an intestinal biopsy, whereas 192 patients (78.4%; 95% CI 73–83%) did not have a biopsy for the following reasons: follow-up serology of known CD (n=18), not referred to pediatric gastroenterologist (n=109), and patients were seen but not biopsied (n=65). Of the last group, a biopsy was not performed for the following reasons: family refused biopsy because they previously started on a GFD (n=6), repeat serology normalized (n=24), endoscopy recommended by pediatric gastroenterologist but family refused (n=1), and pediatric gastroenterologist decided against biopsy (n=34) (e.g., negative HLA DQ2/8, symptoms resolved before consultation, false-positive serology from intercurrent illness, or other autoimmune condition). The majority of these unbiopsied patients were EMA negative: 178 of 192 (92.7%; 95% CI 88–96%). Of the 53 patients with an intestinal biopsy, 23 were EMA positive of whom 12 had biopsies diagnostic of CD (52.2%; 95% CI 33–71%). Of the 30 EMA-negative patients who underwent biopsy, four had biopsies consistent with CD (13.3%; 95% CI 5–30%) (OR=7.1; 95% CI 1.9–26.9%, P<0.01, Table 3). In group C, 9 of the 53 patients who underwent biopsy had a CD-associated condition (17%; 95% CI 9–29%) and of these 3 had CD (two symptomatic with an associated condition). Negative TTG (Group D)
In group D, 574 IgA-sufficient patients had a negative TTG within 6 months before an intestinal biopsy. Of these, 3 patients had biopsies diagnostic for CD (2 female, ages 3.8, 11.8, and 16.3 years at the time of endoscopy), and all presented with typical gastrointestinal symptoms. All were followed and responded to a GFD, and one patient had HLA testing that was DQ2 positive.

Patients with a negative TTG and negative duodenal biopsies for CD within 6 months of the biopsy were categorized as true negatives (n=571). The most common indication for intestinal biopsy was abdominal pain in addition to other gastrointestinal symptoms such as nausea, diarrhea, weight loss, and constipation (19.1%), followed by symptoms suggestive of inflammatory bowel disease (e.g., bloody diarrhea, weight loss, fatigue, and/or abdominal pain) in 17.2% (Supplementary Table S2 http://www.nature.com/ajg/journal/v110/n5/suppinfo/ajg201587s1.html).

The prevalence of biopsy-proven CD in this IgA-sufficient cohort of children who underwent intestinal biopsy from a general gastroenterology clinic was 34.6% (350/1,011; 95% CI 32–38%). The sensitivity of the TTG was very high (98.7%), with a specificity and positive predicted value (PPV) of 86.4% and 79.4%, respectively. If only tests with a TTG ≥10 × ULN are included, the PPV improves to 95.9% (Table 3).

Patients With Bulbar Biopsy
During the study period, 437 children had positive serology and intestinal biopsies performed. Before recommendations to perform duodenal bulb biopsies, 133 of 177 (75.1%; 95% CI 68–81%) were diagnosed with CD (group 1), whereas after bulbar biopsies were included in the diagnostic protocol (group 2), 214 of 260 (82.3%; 95% CI 77–87%) were diagnosed with CD (OR=1.5; 95% CI 1.0–2.5%, P=0.07). Among the 214 children with CD and bulbar biopsies (group 2), we identified 21 (9.8%; 95% CI 6–14%) with typical changes of CD limited only to the duodenal bulb (71.4% female, median age at diagnosis 8.7 years, range 2.9–17.8 years; Table 4). The clinical presentation and serological profile of these 21 patients were variable as outlined in Table 4.

Of the 162 patients with a TTG ≥10 × ULN and bulbar biopsy, 6 had findings diagnostic of CD only in the duodenal bulb (3.7%). However, 10/73 (13.7%) and 5/25 (20%) of patients with a TTG 3–10 × ULN and 1–3 × ULN, respectively, had changes only in the duodenal bulb (each P<0.01 when compared with TTG ≥10 × ULN). IgA-deficient Patients
Over the study period, 25 patients had IgA deficiency (Supplementary Table S3 http://www.nature.com/ajg/journal/v110/n5/suppinfo/ajg201587s1.html), of whom 20 had gastrointestinal symptoms. Six patients had biopsies diagnostic of CD. The prevalence of IgA deficiency in the 17,505 children who had a celiac testing was 0.14% (25/17,505; 95% CI 0.9–0.21%) or 1 in 700. The prevalence of CD in IgA-deficient patients who underwent biopsy was 30% (6/20; 95% CI 14–52%), and the prevalence of IgA deficiency in biopsy-proven CD was 1.7% (6/356; 95% CI 0.8–3.6%) or 1 in 60 patients.

Discussion
Our retrospective study describes the outcome of consecutively enrolled children with positive and negative celiac serology who underwent intestinal biopsy. ESPGHAN recently published guidelines on the diagnosis of CD in children,[2] and our study is the largest, single-center experience published thus far evaluating the performance of the ESPGHAN guidelines,[8–12] TTG, and EMA in children from a general pediatric gastroenterology clinic. It contains a large cohort of patients including those with negative serology and negative biopsies for CD. Published studies thus far reporting on the high positive and negative predictive value of the TTG have been based on populations with a high prevalence of CD (>65%). As the prevalence of CD drops below 35–40%, the PPV of TTG-based tests drops to <80%.[13] The prevalence of CD in our cohort was 35%, and this more closely reflects a typical referral-based pediatric gastroenterology practice. A recent meta-analysis of diagnostic celiac antibody testing in children[14] described that, based on enzyme-linked immunosorbent assay testing, the specificity of the TTG ranges between 77.8 and 100%, with the majority of studies reporting specificities >95%. However, a pooled estimate was not performed because of the heterogeneity of the studies included. Multiple medical conditions are known to give rise to a falsely positive TTG, including other autoimmune diseases such as type 1 diabetes mellitus, inflammatory bowel disease, liver disorders, rheumatologic conditions, as well as acute viral infection.[15–18] The EMA is more specific for CD with a pooled specificity of 98.2%.[14]

Our study presents the PPV for low, moderate, and high titers of TTG when the EMA is positive and negative, and our data highlight the strength of EMA testing, especially at low TTG titers. When the TTG is mildly elevated (i.e., 1–3 × ULN) and EMA negative, the PPV of biopsy-proven CD is only 13%, but it increases to 52% with a positive EMA. Thus, asymptomatic patients with such low TTG titers and a negative EMA should have their celiac serology followed rather than undergo immediate biopsy. The yield of a positive biopsy increases if the TTG titers rise or the EMA becomes positive. When the TTG is moderately elevated (i.e., 3–10 × ULN), the PPV is only 40% if the EMA is negative and increases to 76% with a positive EMA, supporting the recommendation that these patients should be referred to a pediatric gastroenterologist for evaluation as CD can only be diagnosed with certainty with duodenal biopsies rather than with serology alone.

The ESPGHAN guidelines include an algorithm for the “nonbiopsy” diagnosis of CD in a specific patient population (symptomatic child, TTG ≥10 × ULN, positive EMA, positive HLA DQ2, and/or DQ8 and family agreement).[2] In applying these “nonbiopsy” criteria to our cohort, 98.2% (95% CI 95–99%) of symptomatic children with such high TTG titers and positive EMA could have been initially diagnosed without an intestinal biopsy. At our center, this would have eliminated ~60 endoscopies per year (or 50% of all endoscopies performed to evaluate for CD per year). Four patients, however, who met the ESPGHAN “nonbiopsy” criteria had initial biopsies not diagnostic of CD. All were either HLA DQ2 and/or DQ8 positive; thus, genetic susceptibility testing was not helpful in identifying these false-positive patients. If the nonbiopsy algorithm is applied more strictly to patients with an EMA ≥1:80, a relatively high titer, we achieved 100% PPV. Furthermore, all patients whether symptomatic and asymptomatic with an EMA ≥1:80 had biopsies consistent with celiac disease. Thus, future studies may further explore the possibility of designing a “nonbiopsy” algorithm for both symptomatic and asymptomatic patients with very high EMA titers to achieve 100% specificity and PPV. In our experience, we observed that families who have another member with CD were most accepting of the nonbiopsy diagnosis, but this has not been studied formally.

The pediatric celiac guidelines also reaffirm the importance of multiple duodenal biopsies including at least one or two from the duodenal bulb,[2] as the findings of CD may be more severe in the bulb compared with the rest of the duodenum[4] or may be found exclusively in the bulb.[3–6] In our study, 20% of patients with low titer TTGs (1–3 × ULN) and intestinal biopsy had changes diagnostic of CD only in the duodenal bulb, again highlighting the importance of bulbar biopsies, especially in patients with low titer TTGs.

One concern in not performing intestinal biopsies is that other gastrointestinal pathology may be missed. In reviewing the biopsies of the 217 patients who would have met the ESPGHAN “nonbiopsy” criteria, 206 patients had antral biopsies, of which 58% were normal, whereas 31% had mild chronic lymphocytic gastritis, of which CD is likely the cause. One patient was diagnosed with Helicobacter pylori. Forty patients also had esophageal biopsies of which 78% were normal, whereas 20% had pathological changes. Six patients had mild reflux esophagitis, but only one patient displayed heartburn symptoms and was started acid suppressor therapy. One patient was diagnosed with esophageal candidiasis. Thus, only three patients (1.4%) had significant pathology on the upper endoscopy that would have been missed.

Patients with selective IgA deficiency deserve particular attention when being evaluated for potential celiac disease. As demonstrated in previous studies[19,20] and reaffirmed in our cohort, the prevalence of selective IgA deficiency in patients with CD is higher as compared with the general population (1 in 60 vs. 1 in 700). Furthermore, the prevalence of CD in patients with selective IgA deficiency was 30% in our cohort, and this is also substantially higher than the general population risk. Although many patients with associated conditions and CD are asymptomatic at the time of screening, all of our biopsy-positive patients with selective IgA deficiency had gastrointestinal symptoms at the time of biopsy.

The IgA and IgG antibodies to deamidated gliadin peptides have received increasing attention to improve antibody testing for CD. Recently, a multicenter study that utilized the combination of IgG deamidated gliadin peptides and IgA TTG demonstrated superiority to measuring IgA TTG alone as the initial diagnostic test.[11] This combination eliminated the need to measure serum IgA to identify IgA-deficient children and may improve accuracy in children <2 years of age where serum IgA levels vary. Combined testing may increase the number of patients who would not require a biopsy. Prospective studies are required to confirm this finding before incorporating it into the nonbiopsy algorithm.[2,11] A limiting factor of this study is its retrospective design. However, we enrolled consecutive patients with celiac serology from a laboratory database, thus minimizing the risk of inappropriately excluding patients. Another limitation is the time lapse between the celiac serology and the intestinal biopsy (≤6 months). Although patients were asked to continue on a minimum of 3 g of gluten a day, the equivalent of one slice of bread, until the time of biopsy, it is possible some did not report limited gluten consumption. Third, before 2008, most patients with low titer (1–3 × ULN) TTGs underwent intestinal biopsy. As most of these patients had normal biopsies, our practice changed to recommend repeating the TTG as a first measure. This potentially introduces selection bias as the number of patients with these low titers and negative EMA are underrepresented by our data. Finally, in potentially applying our data one has to be mindful of the fact that there is currently a lack of standardization between TTG assays that results in different performance characteristics with each assay.[21] Thus, although we reported our data using common multiples of the ULN of TTG as outlined in the updated ESPGHAN guideline, these results may not be translatable for use in all centers. Use of more specific tests such as the EMA can be very helpful, especially in managing patients with very high as well as very low titer TTGs. In conclusion, the TTG is a highly sensitive test screening test for CD with a 99.4% negative predictive value. The test performance, however, depends on the degree of elevation of the TTG. If available, a positive EMA greatly improves the PPV of the TTG. Furthermore, before a center applying the ESPGHAN nonbiopsy criteria, it is important to evaluate how the TTG serology performs to avoid inappropriate management.

Pauline Anderson
May 14, 2015

Having celiac disease (CD), an autoimmune disorder characterized by a sensitivity to gluten, more than doubles the risk for neuropathy, a new study shows.

“In patients with neuropathy and no obvious cause, celiac disease should be considered,” said Jonas Ludvigsson, MD, PhD, professor of clinical epidemiology, Karolinska Institutet, a pediatrician at Örebro University Hospital, Stockholm, and president, Swedish Pediatric Society.

As well, said Dr Ludvigsson, physicians managing patients with CD should be aware of their increased risk for neuropathy.

The study was published online May 11 in JAMA Neurology

Lasting Risk
In Sweden, at least 90% of patients suspected of having CD undergo a small-intestine biopsy before diagnosis. Researchers linked nationwide data on biopsy-verified CD from Swedish pathology registers to data on neuropathy from the Swedish National Patient Register. The diagnosis was validated through examination of medical records for a diagnosis of villous atrophy, which is almost exclusively caused by CD.

Researchers also linked data on CD to information from the Prescribed Drug Register in Sweden.

The analysis included 28,232 patients with CD and 139,473 controls matched for age, sex, calendar year, and county. Among patients with CD, the median age of diagnosis was 29 years.

During a median of 10 years, 198 patients with CD were diagnosed with neuropathy (0.7%) compared with 359 controls (0.3%). The absolute risks of neuropathy were 64 per 100,000 person-years for patients with CD and 15 per 100,000 person-years for controls, which corresponded to a hazard ratio (HR) of 2.5 (95% confidence interval [CI], 2.1 – 3.0; P < .001). Adjusting for educational level, socioeconomic status, country of birth, type 2 diabetes, several autoimmune disorders associated with CD (including type 1 diabetes, thyroid disease, and rheumatoid arthritis), vitamin deficiencies, and alcoholic disorders had only a marginal effect on the risk estimate (HR, 2.3; 95% CI, 1.9 - 2.7). The risk was highest in the first year after a CD diagnosis, when physicians might have been more prone to investigate for neuropathy, but there was also a significantly increased risk after the first year. For example, the HR for developing neuropathy in patients with CD at more than 5 years of follow-up was 2.2. There were no differences in increased neuropathy risk between male and female patients with CD. Age at diagnosis also didn't influence risk estimates for neuropathy. When the outcome was restricted to neuropathy in those with a record of neuropathy-associated medications, the association between CD and neuropathy remained. The risk varied according to type of neuropathy. Celiac disease was most strongly associated with mono-neuritis multiplex (with an HR of 7.6). The next strongest link was to autonomic neuropathy (HR, 4.2). There was no association between CD and acute inflammatory demyelinating polyneuropathy (HR, 0.8). The study did not have enough statistical power to examine the association between CD and multifocal motor neuropathy, which has been reported by other researchers. Bidirectional Association
There also seemed to be a bidirectional association between CD and neuropathy in that the association existed before the CD diagnosis.

“That is probably because some patients have undiagnosed celiac disease and are then at increased risk of neuropathy — and only after the neuropathy diagnosis is the celiac disease detected,” commented Dr Ludvigsson. “But it could also mean that celiac disease and polyneuropathy share a common cause or risk factor.”

Other possible mechanisms linking celiac disease with neuropathy include chronic inflammation and malnutrition. A deficiency of vitamin B12 has been found to be associated with CD and with neuropathy, suggesting that this deficiency may help explain the connection between the two conditions, said Dr Ludvigsson.

However, the authors noted that the influence of vitamin deficiencies did not significantly affect the risk estimate in the study.

The researchers didn’t investigate whether a strict gluten-free diet would prevent neuropathy in patients with CD, but according to Dr Ludvigsson “that would make an interesting study.”

Given the autoimmune nature of CD, the data reinforce the potential role of immunologic mechanisms for the development of neuropathy, said the authors.

While other studies have found a similar association between celiac disease and neuropathy, this new analysis used a nationwide sample of patients, so it included “average patients” with CD, commented Dr Ludvigsson. “Some earlier studies primarily studied patients with celiac disease in specialist centers, which makes it is difficult to calculate a correct risk for neuropathy.”

The size of the study sample also enabled researchers to calculate a more precise risk estimate than was the case in the past, according to Dr Ludvigsson. The large number of patients also allowed investigators to study subtypes of neuropathy. “That has not been done on a large scale before,” he said.

Future related research should include electrophysiologic studies, thorough serum evaluations, prior drug histories, and skin biopsies to evaluate for small-fiber neuropathy, said the authors. The study results suggest that screening could be beneficial in patients with neuropathy, they concluded.

“In patients with neuropathy where there is a plausible cause, such as high alcohol consumption or type 1 diabetes, looking for celiac disease may not be necessary,” said Dr Ludvigsson. “But in cases where there is no obvious cause for the neuropathy, I think screening for celiac disease is appropriate.”

The estimated prevalence of CD is 1%. Research indicates that about 60% of patients with CD are women.

The association between CD and neuropathy was first reported in 1966. Other autoimmune disorders also increase the risk for neuropathy.

Strong Case
Asked to comment, Shamik Bhattacharyya, MD, Department of Neurology, clinical fellow in neurology, Massachusetts General Hospital, Brigham & Women’s Hospital, and Harvard Medical School, Boston, noted the study’s strengths, particularly the very large number of participants in both study groups, and the duration of follow-up.

The study also makes a strong case for the increased risk for neuropathy in patients with CD relative to the general population, said Dr Bhattacharyya. However, he pointed out that the absolute risk remains small at 64 people per 100,000 patients followed for 1 year.

“For the larger population of patients with neuropathy without symptoms of celiac disease such as diarrhea, the role of testing for disease, if any, remains unclear.”

Any person with neuropathy is also at relatively increased risk for CD — again a small absolute risk — but who those patients are remains unknown, added Dr Bhattacharyya.

But what he found “particularly provocative” about the study was that the risk for neuropathy remained increased for years after the diagnosis of celiac disease.

“The patients in this study probably were treated for celiac disease with a gluten-free diet. Since their risk remained elevated even with this diet, we really don’t know whether this treatment even has any effect on the risk of neuropathy. This is particularly relevant for patients with neuropathy without diarrhea who test positive for antibodies associated with celiac disease.”

Dr Ludvigsson and Dr Bhattacharyya have disclosed no relevant financial relationships.
JAMA Neurol. Published online May 11, 2015. Abstract

A Population-Based Study From England
Alyshah Abdul Sultan PhD; Laila J Tata PhD; Kate M. Fleming PhD; Colin J. Crooks PhD; Jonas F. Ludvigsson PhD; Nafeesa N. Dhalwani PhD; Lu Ban PhD; Joe West PhD
Disclosures
Am J Gastroenterol. 2014;109:1653-1661. 

Abstract and Introduction

Abstract
Objectives Evidence-based information about adverse birth outcomes and pregnancy complications is crucial when counseling women with celiac disease (CD); however, limited population-based data on such risks exist. We estimated these for pregnant women with CD diagnosed before and after delivery.

Methods We included all singleton pregnancies between 1997 and 2012 using linked primary care data from the Clinical Practice Research Datalink and secondary care Hospital Episode Statistics data. Risks of pregnancy complications (antepartum and postpartum hemorrhage, pre-eclampsia, and mode of delivery) and adverse birth outcomes (preterm birth, stillbirth, and low birth weight) were compared between pregnancies of women with and without CD using logistic/multinomial regression. Risks were stratified on the basis of whether women were diagnosed or yet undiagnosed before delivery.

Results Of 363,930 pregnancies resulting in a live birth or stillbirth, 892 (0.25%) were among women with CD. Diagnosed CD was not associated with an increased risk of pregnancy complications or adverse birth outcomes compared with women without CD. However, the risk of postpartum hemorrhage and assisted delivery was slightly higher among pregnant women with diagnosed CD (adjusted odds ratio (aOR)=1.34). We found no increased risk of any pregnancy complication among those with undiagnosed CD. We only observed a 1% absolute excess risk of preterm birth and low birth weight among undiagnosed CD mothers corresponding to aOR=1.24 (95% confidence interval (CI)=0.82–1.87) and aOR=1.36 (95% CI=0.83–2.24), respectively.

Conclusions Whether diagnosed or undiagnosed during pregnancy, CD is not associated with a major increased risk of pregnancy complications and adverse birth outcomes. These findings are reassuring to both women and clinicians.

Introduction
Subclinical pathological evidence of celiac disease (CD) is present in around 1% of most European populations,[1] of which approximately 0.2% have been clinically diagnosed with CD.[2] This suggests that about 10 in 1,000 pregnant women could have some form of latent or undetected CD and that about 2 in 1,000 deliveries per year in the United Kingdom will be in women with known CD. Given this estimated prevalence and the potential adverse physiological effects that CD might engender, it is surprising that very few good studies have been produced that have tried to quantify the risks to the mother and the child around delivery. The studies[3–9] that have tried to quantify the risks of pregnancy and delivery-related adverse events among women with CD can be categorized broadly as either case series of individuals, in single or multiple centers pooled together, or registry based. Most case series[4,10,11] have been based on a small number of pregnant women with known CD (i.e., <150) or pregnant women who are screened for positive serology leading to the identification of a small number of women with previously undiagnosed CD. Unsurprisingly, the results are conflicting; e.g., Martinelli et al.[11] reported that the 12 pregnant women that they found to have undiagnosed CD were more likely to have babies with low birth weight compared with those with negative serology. However, a similar study based on 52 undiagnosed cases from multiple centers found no excess risk of low birth in offsprings.[10] Larger studies from Sweden and Denmark[7,8] have used inpatient national registries to identify women with CD, which provide greater number of women but appear to underestimate the prevalence of CD. This may explain their findings of an increased risk of some adverse birth outcomes for both mother (cesarean section) and child (low birth weight, intrauterine growth restriction)[7,8] if the populations they have studied were not generalizable to all women with CD. It appears therefore that accurate contemporary estimates of the risk of adverse birth outcomes among women with undiagnosed and diagnosed CD that are generalizable to the majority are absent. Therefore, we have carried out a population-based cohort study using primary and secondary health-care data from England with the aim of quantifying the risks of pregnancy complications and adverse birth outcomes among women with CD. Methods

Study Population
We used the Clinical Practice Research Datalink (CPRD),[12] which is a large longitudinal UK database of computerized primary care (i.e., general practice) records. The vast majority of the UK population is registered with general practitioners (GPs), who are responsible for overseeing a patient’s medical care, which includes coordination of their health care from hospital or other secondary care facilities. The CPRD includes practices that have met training standards in their recording of clinical information using Vision software and who have consented to be included in the database.[13] All patients within a consented practice are automatically included.

Around 53% of the CPRD practices are linked to Hospital Episode Statistics (HES)[14] data that contain information on all hospitalizations in England including all discharge diagnoses and procedures. The anonymized patient identifiers from CPRD and HES were linked by a trusted third party using the National Health Service number, date of birth, postcode, and gender.[15] First, patients were matched exactly according to the National Health Service number (over 90% of patients are linked in this way), with the remaining patients linked probabilistically on the basis of postcode, date of birth, and gender. As HES only covers English hospitals, practices from Northern Ireland, Wales, and Scotland were excluded. Previously, data from the linked portion of the CPRD have been shown to be broadly representative in terms of age and sex distribution to data from the UK population published by the Office for National Statistics.[16] We identified all singleton pregnancies recorded in HES between 1997 and 2012 that ended in a live birth or a stillbirth among women aged 15–44 years as our study population. We therefore had prospectively recorded health and socio-demographic information for women before, during, and after pregnancy.

Mothers with CD were defined as those with a medical Read code for a diagnosis of CD in their primary care records (Read codes J690.00 CD, J690.13 Gluten enteropathy, J690.14 Sprue-nontropical, J690100 Acquired CD, and J690z00 CD NOS). We did not include women who had diagnoses of dermatitis herpetiformis (DH); however, women with both diagnoses (CD and DH) were retained in the CD group. Each woman with CD was assigned a date of diagnosis corresponding to the date of her first record of CD or the date of her first prescription of a gluten-free product. These women were then classified as having the CD diagnosis before delivery (diagnosed CD) or afterward (undiagnosed CD) for each pregnancy in the study. Pregnancies among women with a recorded history of CD before the study start date were included in the diagnosed CD group. The method that we used for defining CD has been validated in general practice databases with the positive predictive value ranging between 81 and 89%.[2]

Pregnancies in which women’s first diagnosis of CD was recorded in the 12 weeks postpartum were also included in the diagnosed CD group. We used this conservative approach to include women who may have had well-controlled CD not requiring medical/GP contact before or during pregnancy but whose postpartum follow-up may have resulted in a recorded diagnosis. Moreover, the diagnostic work-up/process for CD may be long and therefore these are unlikely to be new diagnoses.

Our comparison group consisted of pregnant women without any recorded diagnoses of CD or DH in their primary or secondary care data. Pregnant women who received a gluten-free prescription in the absence of any CD or DH diagnosis at any point during the study period were also excluded.

Defining Outcomes
We extracted information on pregnancy complications, which included postpartum hemorrhage, antepartum hemorrhage, and pre-eclampsia/eclampsia based on International Classification of Disease version 10 codes from secondary care. Mode of delivery was categorized as normal vaginal delivery, assisted vaginal delivery (forceps, breech, or vacuum), and emergency or elective cesarean section. Information on length of gestation was categorized as normal (37–42 weeks), preterm (<37 weeks), or prolonged (>42 weeks), whereas infant’s birth weight was categorized as normal (2,500–4,500 g), low birth weight (<2,500 g), or macrosomia (>4,500 g). We also analyzed birth weight as a continuous variable. Finally, we also extracted information on pregnancies resulting in stillbirths.

Defining Maternal Covariables
For each pregnancy, information on maternal factors during or before pregnancy was extracted from the women’s medical records. Maternal age at delivery was categorized into six age groups (15–19, 20–24, 25–29, 30–34, 35–39, and 40–44 years), whereas calendar year was considered in three categories (1997–2001, 2002–2007, and 2007–2012). Information on body mass index (BMI; the latest measure recorded by the GP before the estimated date of conception categorized according to World Health Organization classification), smoking status (the latest measure recorded by the GP before delivery), and ethnicity (as recorded in HES and categorized as white or nonwhite[17] was also obtained. Socioeconomic status was defined as the area in which the general practice was located, at which the patient was registered (quintiles by rank of Indices of Multiple Deprivation.[18] Finally pregnant women were defined as having diabetes (pre-existing type 1 or type 2) if it was recorded either in primary or secondary care data, or if they had received a prescription for an antidiabetic medication (insulin or oral hypoglycemic agents) any time before delivery.

Statistical Analysis
We calculated the proportions of pregnancies with complications or adverse birth outcomes that occurred in women with and without a diagnosis of CD. These proportions were then stratified by the status of the pregnancy with respect to having diagnosed or undiagnosed CD. We used logistic regression to calculate odds ratios (OR) and 95% confidence intervals (95% CI) to assess the associations of CD overall, diagnosed CD, and undiagnosed CD with each pregnancy complication and adverse birth outcome. For categorical outcomes (e.g., mode of delivery), multinomial logistic regression was used and relative risk ratios and corresponding 95% CIs were calculated. These estimates were adjusted for all potential confounders: maternal age, BMI, smoking status, diabetes, ethnicity, calendar year, and socioeconomic status. Missing information on BMI, smoking status, and birth weight was categorized as a separate category and included in the analysis. We used linear regression to calculate the mean grams of difference in the birth weight of infants born to women with CD compared with those born to women without CD while adjusting for all covariables. As some women experienced more than one pregnancy during the study period, a clustering term (in our regression models) was fitted. For the purpose of this study, we only considered pregnancy complication or adverse birth outcome to be truly associated with CD if we observed an absolute risk difference (between women with and without CD) of 3% or more. All outcomes with the absolute risk difference of less than 3% were considered to be within the random variation of the data.

Sensitivity Analyses
We undertook four additional analyses to ensure the robustness of our results. First, we repeated our analysis by restricting the group of women with CD to only those who had received a gluten-free prescription to increase the specificity of our disease definition. Second, we assessed the extent to which women had only hospital recordings of CD using International Classification of Disease version 10 codes (K90.0; with no evidence in their primary care records) and repeated our analysis including these cases. We also repeated our analyses reclassifying those pregnancies in women who had their diagnosis recorded for the first time within the 12 weeks postpartum as undiagnosed CD (rather than diagnosed). Finally, we assessed whether there is an independent increase in the risk of adverse birth outcomes regardless of the mode of delivery. This was done by restricting our analysis to only those women who underwent a normal vaginal delivery. All analyses were carried out using Stata SE version 11.2 (Stata Statistical Software, College Station, TX).

Ethical Statement
This study was approved by the Independent Scientific Advisory Committee reference number=10_193R.

Results

Study Population
Among 276,586 women in our study population, there were 364,186 singleton pregnancies resulting in a live birth or a stillbirth. We excluded 0.07% (n=256) of pregnancies in women with DH without CD (0.01%) or who had gluten-free prescriptions without any evidence of concurrent CD (0.05%). This resulted in a total of 363,930 pregnancies, which were included in the analysis. The overall proportion of pregnancies among women with CD was 0.25% (892 out of 363,930) with the median age at diagnosis of 29 years (inter quartile range=20.2–34.7). Of these pregnancies, 62% (n=551) were among women with diagnosed CD and 38% (n=341) among women with undiagnosed CD. Table 1 shows the maternal characteristics for all pregnancies in women with and without CD. Compared with women without CD, women with CD had lower BMI, were less likely to be smokers and had a higher prevalence of diabetes. Pregnant women with diagnosed CD were slightly older than those with undiagnosed CD but otherwise had similar maternal characteristics.

Pregnancy Complications and Adverse Birth Outcomes Among Women With CD
Table 2 shows the absolute risks of pregnancy complications and adverse birth outcomes among pregnancies in women with diagnosed and undiagnosed CD and those in women without CD. Overall, pregnancies in women with CD had a slightly higher incidence of postpartum and antepartum hemorrhage, preeclampsia/eclampsia, cesarean section delivery, assisted delivery, stillbirth, preterm birth, and low-birth-weight babies compared with pregnant women without CD (absolute risk difference of <2.5%), all of which were not statistically significant. Diagnosed CD
Among pregnancies in women diagnosed with CD, we found a slightly higher risk of postpartum hemorrhage with an absolute risk (AR) of 13.2% (Table 2) than women without CD. This corresponded to a 3.5% excess absolute risk and a 34% increased adjusted relative risk (OR=1.34 (95% CI=1.04–1.72)) compared with pregnancies in women without CD (Table 3). There was no statistically significant increased risk of preeclampsia/eclampsia, antepartum hemorrhage, or cesarean section delivery. We observed a greater risk of assisted deliveries among those with diagnosed CD (AR=15% vs. 12% in women without CD), which corresponded to a 34% increased relative risk (adjusted OR (aOR)=1.34, 95% CI=1.05–1.71) and a 3% excess absolute risk. The risk of stillbirth, preterm birth, and babies born with low birth weight was similar among pregnancies in women with diagnosed CD and without CD. Finally, there was no mean difference in the birth weight of babies born to women with diagnosed CD compared with women without CD (adjusted mean difference=−15 g; 95%CI=−72 g to 41 g).

Undiagnosed CD
Among pregnancies in women with undiagnosed CD, we found no overall increased risk of postpartum hemorrhage, pre-eclampsia/eclampsia, antepartum hemorrhage, or having an assisted delivery or emergency cesarean section (Table 2 and Table 3). Compared with pregnancies among women without CD, the risk of preterm birth was roughly similar among those with undiagnosed CD (6.5% vs. 7.6%; aOR=1.24; 95% CI=0.82–1.88). We found that pregnancies in women with undiagnosed CD resulted in babies with a mean birth weight 65 g lower than babies born to women without CD; however, this difference was not statistically significant at the 5% level (95% CI=−151 g to 20 g) after adjusting for all potential confounding factors.

Sensitivity and Other Analyses
Sixty-seven percent of pregnant women with CD received a gluten-free prescription during the study period. Our findings for both diagnosed and undiagnosed CD remained broadly consistent when we added celiac cases recorded solely in the secondary care data (n=176) and restricted our analysis to only those cases who received a gluten-free prescription (n=595; Table 4). However, we did find a statistically significant increased risk of infants with low birth weight born to mothers with CD compared with those without CD (aOR=1.83; 95% CI=1.05–3.17). When we included pregnancies in women with CD who had been classified as diagnosed because of their diagnosis being in the postpartum period as undiagnosed, our risk estimates remained unchanged (Table 5). Similarly, our estimates for pregnancy complications and adverse birth outcomes remained unchanged when we restricted our analysis to pregnant women who underwent normal vaginal delivery (Table 5). This was with the exception of postpartum hemorrhage, which was not associated with increased risk among women with diagnosed CD.

Discussion

Main Findings
In this large nationally representative cohort of more than 360,000 singleton pregnancies resulting in a live birth or a stillbirth, we have provided contemporary, generalizable, population-based estimates of the proportion of pregnancies in England that occur in women either with a diagnosis of CD before delivery or following it and their risk of pregnancy complications and adverse birth outcomes. We found that 0.25% of pregnancies were among women who had or went on to develop CD, of which over one-third are not diagnosed until after delivery. With the exception of postpartum hemorrhage and assisted delivery, we observed no increased risk of pregnancy-associated complications or adverse birth outcomes among the pregnancies in women with diagnosed CD compared with those without the diagnosis. Similarly, we also found that undiagnosed CD is not associated with pregnancy complications and adverse birth outcomes.

Strength and Limitations
We have conducted one of the largest studies to determine the risk of pregnancy complications and adverse birth outcomes in CD using data from both primary and secondary care while adjusting for important confounding factors such as BMI, smoking status, and maternal diabetes. Our study used an open cohort approach, with prospectively collected data from across England covering 3% of the total UK population with a similar age and sex distribution to the population as a whole. Furthermore, HES is the primary source of maternity statistics in England where birth outcomes have been externally validated with high accuracy.[19] Although our study lacked information on the severity of CD, the use of general practice data to ascertain CD diagnosis makes our study findings not only generalizable to the singleton pregnancies resulting in a live birth or a stillbirth in England but also to other developed nations with similar health-care systems. A weakness of this study is the lack of histological and serological information common to cohorts that have been studied in specific secondary or tertiary centers or with complete linkages to pathology systems. However, because the definition of CD that we have used is based on recording of a clinical diagnosis by the GPs, it reflects the real world of clinical practice, as it occurs in the general population of the United Kingdom. This, in turn, has allowed us to study a large number of pregnancies, which would not otherwise be easily possible in a bespoke cohort study. Fortunately, this method of defining CD has been validated in general practice databases with a positive predictive value ranging between 81 and 89%, which increases when prescription data are also used.[2] When we increased the specificity of our diagnosis by restricting our analysis only to cases with a supporting gluten-free prescription, our estimates remained broadly similar for both diagnosed and undiagnosed CD, indicating that any misclassification inherent to our overall definition is likely to have had a small effect on our estimates. We do acknowledge that CD diagnoses recorded in inpatient data in England have not been validated. For this reason, we only included them in our sensitivity for which our estimates remained unaltered.

It is important to highlight that 33% of pregnant women with CD diagnosis did not receive gluten-free prescriptions, which may be due to a number of factors. For instance, these prescriptions are expensive and aside from during pregnancy/early postpartum (or if other comorbidities are present) women of this age do not routinely get free prescriptions in England, and hence they may purchase specific gluten-free products directly. Moreover, a relatively short duration of follow-up (i.e., our inability to capture those prescriptions) and a high proportion of “prevalent” cases (i.e., women giving up those prescriptions later on after diagnosis) may also be contributory factors. Another limitation of this study is the lack of compliance data on a gluten-free diet among those with diagnosed CD. Similar to most studies conducted on the topic, we assumed that all women with diagnosed CD are broadly compliant with a gluten-free diet, which seems reasonable given previous evidence suggesting that complete nonadherence to a gluten-free diet is uncommon among patients with CD.[20] There could of course be some misclassification in terms of children of mothers with and without CD in our study. It is likely that some mothers without CD in our study may have undiagnosed disease throughout the whole study period. This, however, should only bias our results toward the null, i.e., of no increase in the risk of pregnancy complications and adverse birth outcomes.

We also recognize that our lack of complete data on BMI and birth weight could bias our estimates. However, we treated missing data as a separate category and included them in our analysis. The fact that we were able to use data on BMI does, however, give us an advantage over other studies[3,7,8] in this field, which have been previously unable to. We observed lower proportions of pregnant women with undiagnosed CD in more recent years compared with those with diagnosed CD. This was probably owing to the fact that in order to be undiagnosed a pregnancy needs to occur earlier in the data and vice versa for those with diagnosed CD. It is important to note that our study may have limited power to show small excess risks for certain outcomes (e.g., stillbirths). Therefore, one cannot rule out minor risk increases associated with these outcomes owing to a potential for type 2 error.

Comparison With Previous Literature
The overall prevalence of CD in our study among pregnant women was calculated to be 0.25%. Although this proportion is much lower than most small-scale hospital-based studies (1%),[4,11] it is not surprising as our cases included those with a clinical diagnosis of CD as opposed to positive serology identified via screening. Our proportions are still higher than those reported by most large registry-based studies (around 0.07%).[7,8] This may be due to their reliance on inpatient hospital data and lack of outpatient or primary care data leading to the underestimation of the prevalence. We did not observe increased risks of preterm birth and low birth weight among those with diagnosed CD, a finding consistent with the available population-based studies.[3,7,8,11] Our finding of a 34% increased risk of postpartum hemorrhage and assisted deliveries among those with diagnosed CD is new, as previous studies have not reported this.

Overall, we found no increased risk of low birth weight and preterm birth among undiagnosed celiac mothers. This finding is consistent with a multicenter study conducted by Greco et al.[10] where 5,055 mothers were screened for CD, of which 51 (1%) had a positive result. The study concluded that undiagnosed CD, although common in pregnancy, is not associated with an excess risk of preterm delivery, low birth weight, abortion, or intrauterine growth restriction. Our findings do, however, contradict some of the largest registry-based studies to date.[3,7,8] For instance, Ludvigsson et al.[7] in their population-based study demonstrated that women with undiagnosed CD were 71% more likely to have preterm birth and over two times more likely to have infants with low birth weight. These different findings to ours could be because the cases identified through hospital-based registers may suffer from a more severe form of disease than those diagnosed within the general population. Our study showed no increased risk of cesarean section in the undiagnosed CD group in contrast to an increased risk among this group in Swedish data.[7] One explanation could be the difference in the medical indication and the incidence of cesarean sections in the United Kingdom and Sweden (26%[21] vs. 17%.[22] Although we did not find an increased risk of stillbirth, we did not assess the risk of earlier fetal losses in our study, and previous studies have indicated that women with CD may have an increased risk of miscarriage,[9,11] which needs further assessment. With regard to overall fertility, although there is mixed evidence as to whether women with unexplained infertility may be more likely to have undiagnosed CD than the general population,[23,24] there is evidence[9] suggesting that women with CD have fertility rates similar to those of the general population. The study by Tata et al.[9] showed no difference in the fertility rate for women with incident vs. prevalent CD, and the prevalence of CD in women who had children was 0.2%, which was similar to the overall prevalence of the disease in the female population.

The only persistently increased risk that we observed was a 34% increased risk of postpartum hemorrhage and assisted deliveries among those with diagnosed CD, which has not been reported before. This may be due to the higher proportion of women undergoing assisted delivery, which may increase the likelihood of postpartum hemorrhage compared with normal vaginal delivery.[25] This increased risk in women with diagnosed CD may therefore be due to more assisted deliveries rather than disease-related per se.

Conclusion and Implications
Most women with CD diagnosed either before or after pregnancy will have a pregnancy and delivery that is not complicated by an adverse event. Our findings do suggest that among women already diagnosed with CD there may be a small increase in the risk of a pregnancy being complicated by a postpartum hemorrhage, but the reasons for this are not entirely clear. Overall, our results should be reassuring to both women and practitioners. However, this study does not preclude that the lack of increased risk observed among pregnant women with CD was due to an adequate treatment of CD before childbirth, thereby optimizing maternal health.

A Prospective 1-year Follow-up Study of Adult Patients With Coeliac Disease
G. Galli; G. Esposito; E. Lahner; E. Pilozzi; V. D. Corleto; E. Di Giulio; M. A. Aloe Spiriti; B. Annibale
Disclosures

Aliment Pharmacol Ther. 2014;40(6):639-647. 

Abstract and Introduction

Abstract

Background Adequate gluten-free diet (GFD) is the only treatment for coeliac disease (CD). However, no agreement has been reached on either how and when to assess patient adherence to GFD or its effectiveness on villous atrophy.

Aim To assess, in a prospective study, patient adherence to and efficacy of GFD on histological recovery after 1-year of GFD.

Methods Between 2009 and 2012, we enrolled 65 consecutive newly-diagnosed adult patients (median age 38 years, 18–70) with biopsy-proven atrophic CD. Patients were re-evaluated after 1 year of GFD with duodenal histology, serological assays, symptoms and a dietary interview based on a validated questionnaire. Complete histological recovery was defined as the absence of villous atrophy and ≤30/100 intraepithelial lymphocytes.

Results Overall, 81.5% of patients had adequate adherence (ADA) to GFD, whereas 18.5% had an inadequate adherence (IADA); 66% of ADA patients and no IADA patients achieved complete histological recovery (P < 0.00001). Among ADA patients, antibody seroconversion and symptoms were not significantly different between patients who achieved complete histological recovery and those who achieved partial histological recovery with P = 0.309 and P = 0.197, respectively. Multivariate analysis showed that Marsh 3C was a risk factor for incomplete histological recovery in ADA patients (OR 8.74, 95% CI: 1.87–40.83). Conclusions This study shows that complete histological recovery after 1-year of GFD in adult patients, who are assessed as adherent to the GFD, can be obtained in 66% of patients. Patients with severe histological damage at diagnosis are at risk for incomplete histological recovery 1 year later.

Introduction
Coeliac disease (CD) is an immune-mediated disorder that affects approximately 1% of the Western population.[1,2] Patients with CD have intestinal lesions consisting of varying degrees of villous atrophy, crypt hyperplasia and intraepithelial lymphocytosis, as observed in duodenal biopsies.[3] The only known therapy is a lifelong gluten-free diet (GFD), which can lead to mucosal healing and improvements in symptoms and nutritional parameters. GFD may also prevent the onset of long-term complications, including malignancies.[4]

There is little evidence on the best method of assessing GFD adherence and mucosal healing during GFD. The evaluation of serum coeliac disease-associated antibodies, such as anti-transglutaminase and/or anti-endomysium (Ab tTG IgA and/or EMA), and the assessment of clinical symptoms are the most frequently used methods to assess CD patients during follow-up.[5–9] However, these antibodies often decrease and/or disappear regardless of histological healing and GFD adherence,[10–12] whereas the initial symptoms may improve right after the beginning of the GFD, even if the histological resolution is slower.[6,13,14] Therefore, antibody negativity and the disappearance of initial symptoms are not always reliable markers for assessing adherence and the histological response to diet. In adult patients on GFD, no agreement currently exists as to the necessity of gastroscopic/histological control during follow-up or regarding the appropriate timing.[15] In fact, the existing bodies of evidence contrast one another due to the retrospective nature of most relevant studies, which have used varying follow-up periods (ranging from 9 months to 33 years) and only sometimes adhered to validated methods of assessing GFD adherence.[11,16–20] Thus, few prospective studies have investigated intestinal histological recovery during GFD[12,21,22] using a validated tool for diet adherence.

The aim of this prospective study was to assess the adherence to and the efficacy of GFD on histological duodenal mucosa healing after 1 year of diet in newly diagnosed adult subjects.

Materials and Methods

Study Population
From January 2009 to December 2012, 65 consecutive newly diagnosed patients (72.3% female) with coeliac disease were included. All patients (pts) were adults (median age 38, range 18–70) and had atrophic disease. A total of 57 patients (87.7%) had serological positivity at the time of diagnosis (anti-tTG and/or EMA IgA antibodies), and 19 (29.3%) had autoimmune or endocrinological comorbidities associated with coeliac disease, such as hypothyroidism (n = 9 pts), hyperthyroidism (n = 1 pt), type I diabetes mellitus (n = 4 pts), autoimmune hepatitis (n = 1 pt), psoriasis (n = 3 pts) and multiple sclerosis (n = 1 pt). For each patient, the signs/symptoms leading to CD diagnosis were collected, as follows: 18 patients (27.7%) had gastrointestinal symptoms (including diarrhoea, abdominal pain and distension or irritable bowel syndrome-like symptoms); 39 (60%) presented with extraintestinal manifestations, such as anaemia, nutritional deficiency (including osteopenia or osteoporosis), discomfort or gynaecologic alterations (such as infertility or poliabortivity); and 8 patients (12.3%) were diagnosed by screening due to diseases associated with CD or a family history of CD.

The study was approved by the local (Sant’Andrea Hospital) ethics committee, and written informed consent was obtained from each patient.

Study Design
At baseline, after the gastroscopy with biopsies had been performed but before the start of the GFD, all patients were interviewed using a structured questionnaire to collect their ages, presenting signs and symptoms and comorbidities. Patients were informed about the disease and the importance of following a lifelong GFD. A specific written information sheet regarding management during the first year of GFD was given to all patients. Moreover, before the start of GFD, all patients underwent serological assessment (Ab anti-TtG IgA and EMA, total IgA, red blood cell count, ferritin, triglycerides and cholesterol) and dual-energy X-ray absorptiometry (DEXA) to detect osteoporosis or osteopenia.

After 1 year of GFD, the patients submitted to a follow-up gastroscopy with at least four duodenal biopsies, and serological assays were repeated. GFD adherence was assessed during the clinical examination after 1 year of the diet using a dietary interview according to a validated structured questionnaire consisting of four questions about how the patients managed their GFD.[23] The aim of the questionnaire was to evaluate their real adherence to GFD, which is defined as either adequate, with a score of 3–4, or inadequate, with a score of 0–2.[23,24]

Clinical symptoms were also evaluated. Clinical well-being was defined as the complete resolution of baseline symptoms after 1 year of GFD. Clinical improvement was defined as a resolution of at least 50% of the baseline symptoms after 1 year of GFD. DEXA was repeated after 1 year, when the baseline bone mineral density values were below the normal values.

Diagnostic Investigations
Endoscopic Procedure. Gastroscopy with at least four biopsies obtained from the second part of the duodenum was performed in all patients using a flexible video-gastroscope (Olympus GIF-Q165). The endoscopic appearance was assessed based on the following proposed classifications:[21] ‘normal’ endoscopic appearance, ‘mild’ endoscopic alterations (micronodular bulb, granular mucosa in the second part of the duodenum), ‘moderate’ alterations (scalloping of the duodenal folds, reduction in the duodenal folds) and ‘severe’ alterations (mosaic pattern of the mucosa in the second part of the duodenum and loss of the duodenal folds). The same classification system was used to assess the endoscopic appearance 1 year after beginning the GFD; the endoscopist who performed the follow-up gastroscopy was unaware of the baseline endoscopic appearance.

Histological Classification. The biopsies were examined by an expert pathologist (EP) after haematoxylin and eosin staining and immunohistochemical staining for CD3 counts. The pathologist (EP) was unaware of the clinical data of the patients; biopsies were analysed using the Marsh classification system modified by Oberhuber.[1,3] Complete histological resolution of villous atrophy associated with the absence of crypt hyperplasia and ≤30/100 intraepithelial lymphocytes was defined as ‘complete histological recovery’ (Marsh 0). The partial or absent improvement of at least one grade on the Marsh classification compared with the initial histology was defined as ‘partial histological recovery’ or ‘no histological recovery’, respectively.

Serological Assays
Anti-endomysium (EMA) and anti-transglutaminase (tTG) IgA antibodies were assessed in all patients at diagnosis and at the 1-year point after GFD initiation. An indirect immunofluorescence assay was used to detect the IgA EMA in monkey oesophagus sections. IgA tTG Abs were assayed using an enzyme-linked immunosorbent assay kit commercially available from Eurospital (Trieste, Italy). Other blood assays, such as ferritin, red blood cell counts, total cholesterol, triglycerides and total IgA, were performed using standard laboratory techniques.

DEXA
The bone mineral density (BMD) in the lumbar spine and left femoral neck were measured by dual-energy X-ray absorptiometry (DEXA). The BMD values were expressed as standard deviation scores that compared the individual BMD measurements to those of young adults (T-score). Based on the World Health Organization criteria, T-scores between −1.0 and −2.4 indicated osteopenia, and scores of −2.5 or less indicated osteoporosis.

Statistics
Data are expressed as medians and interquartile ranges or values and percentages. Comparisons between different groups were made using the Fisher’s exact test and Mann–Whitney U-test, as appropriate. A P value <0.05 was considered statistically significant. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to describe the associations and were obtained by logistic regression analysis. Age, gender, anaemia, hypocholesterolaemia and higher grades of histological damage (Marsh 3C) were included in the model to detect any possible factors linked to the persistence of histological duodenal damage. Two-tailed P values <0.05 were considered statistically significant. Statistical analyses were run using a dedicated software (MedCalc Software, Mariakerke, Belgium, version 12). Results
Dietary assessment after 1 year of GFD showed that 53 patients (81.5%) had an adequate adherence to GFD (ADA), whereas 12 patients (18.5%) had an inadequate adherence to GFD (IADA). Table S1 http://onlinelibrary.wiley.com/store/10.1111/apt.12893/asset/supinfo/apt12893-sup-0001-TableS1.docx?v=1&s=d7f30c858792c205c11cc59c3a8f97be5707a4b9 shows the main biochemical, clinical, endoscopic and histological features, none of which was significantly different between the groups of CD patients.

Table 1 describes the responses of patients with ADA and IADA to GFD after 1 year. Regarding the clinical evaluation, 45 patients (85%) with ADA reported clinical well-being, and eight patients demonstrated clinical improvement. Further, two (16.7%) subjects with IADA achieved clinical well-being, and seven patients achieved clinical improvement (P = 0.00001). With regard to specific antibodies, the proportion of patients without seroconversion after 1 year of diet was similar in both groups (29.7% of patients with ADA vs. 30% of patients with IADA).

The gastroscopic findings were normalised in 17 patients (38.6%) with ADA and two patients (22.2%) with IADA (P = 0.331). Only CD patients with ADA achieved a complete histological recovery (Marsh 0) (66% vs. 0%; P < 0.00001), whereas 32% achieved a partial histological recovery. Despite strict adherence to the diet, one patient (2%) did not achieve any histological improvement. No patient with IADA achieved a complete histological recovery; 58.3% achieved a partial histological recovery; and 41.7% did not obtain any histological improvement. Table 2 shows the features of ADA patients with complete histological recovery (n = 35) and partial histological recovery (n = 17) at diagnosis. At univariate analysis, the most severe degree of villous atrophy (Marsh 3C) at diagnosis was present in fewer patients with complete histological recovery than in those with partial histological recovery: n = 9 (25.7%) vs. n = 12 (70.5%) patients, P = 0.0028. No differences were found between the groups with regard to gender, age, body mass index (BMI), comorbidities, presenting sign/symptoms, antibodies positivity or gastroscopic appearance. Regarding the biochemical and nutritional parameters, univariate analysis showed that between patients with complete histological recovery and patients with partial histological recovery, there were no significant differences in the ferritin or triglyceride levels (respectively P = 0.141 and P = 0.964), whereas the haemoglobin and cholesterol levels were lower in patients with partial histological recovery (respectively P = 0.041 and P = 0.008). In patients with osteoporosis, a higher percentage of partial histological recovery (P = 0.036) was observed. A logistic regression model including possible factors linked to the persistence of histological duodenal damage after 1 year of GFD showed that Marsh 3C damage (OR 8.74, 95% CI 1.87–40.83) was associated with a lack of complete histological recovery after 1 year of GFD. Table 3 shows patients' features after 1 year of GFD. Among patients with complete histological recovery, 32 (91.5%) achieved clinical well-being, compared with 13 (76.5%) with partial histological recovery; respectively, three (8.5%) and four (23.5%) of these patients achieved symptom improvement. However, these differences were not statistically significant, at P = 0.197 and P = 0.197, respectively. The antibody seroconversion (Ab tTG IgA and/or EMA) was 80% and 64.7% in patients with complete and partial histological recoveries, respectively, and seven patients (24.1%) with total histological recovery and six (35.3%) with partial histological recovery were still positive for the antibodies. The P value for these results was 0.309, showing no significant difference between the groups. With regard to the gastroscopic findings, normalisation was described in 13 patients (72.2%) with complete histological recovery and in four patients (50%) with partial histological recovery; there was no statistically significant difference (P = 0.366) between the groups. All nutritional parameters were increased after 1 year of GFD compared to baseline, regardless of complete or partial histological recovery and without significant differences. As previously described, one patient did not achieve any histological improvement despite strict adherence to GFD. This patient, at 1 year, did not achieve antibody seroconversion but observed improvement in the clinical status and nutritional parameters at the resolution of anaemia (Hb 11.8 g/dL vs. Hb 13.8 g/dL). This subject was thus considered refractory to the diet. Discussion
This study shows that complete histological recovery is obtained in 66% of patients after 1 year of adequate GFD. It has previously been observed that GFD adherence is highly variable, depending on the population considered; indeed, strict adherence was observed over a range from 36% to 93%.[16,21,22,25–30] In previous studies, interviews performed by dedicated dieticians or using unvalidated questionnaires represented the most common methods of assessing GFD adherence. In our study, we observed that 81.5% of patients had an adequate adherence to the diet, a higher percentage than that observed in previous studies. Most likely, each patient’s awareness of his or her study participation represents a valid explanation for the observed high adherence to GFD; such a phenomenon was also reported by the recent BSG guidelines.[15] The use of a validated dietary questionnaire,[23] also validated in a multicentre setting,[24] at the 1-year follow-up point is a simple and practical method of discriminating those patients with adequate adherence to the diet from those with inadequate adherence.

Concerning mucosal healing, previous studies showed that the percentages of histological recovery after starting GFD are extremely broad, ranging from 8% to 96%, with a median of 46%. However, these results were mostly obtained regardless of the patient’s adherence to GFD.[11,16–21,25–27,31] Although the majority of these studies delegate dietary assessment to dieticians, differences in the methods used and the lack of a validated tool for dietary assessment may explain the observed results’ variability. It has been well established that coeliac patients with inadequate adherence to diet do not completely recover from the histological mucosal damage.[4,8] Our results show that none of the patients with inadequate GFD adherence completely recovered from histological damage; 58.3% showed only partial histological recovery, whereas 41.7% did not achieve any histological recovery. This finding suggests that a validated dietary assessment may be used as a tool to identify those patients who do not follow an adequate GFD to avoid useless gastroscopic control.

Another innovative aspect of this study is represented by the histological criteria used for complete mucosal recovery. The latter status is defined as the absence of villous atrophy and crypt hyperplasia in presence of normal lymphocytic infiltrate (≤30/100 IELs, Marsh 0). Previous studies have considered the disappearance of villous atrophy alone to signal histological healing after GFD, thereby considering non-atrophic damages, such as Marsh 1 and Marsh 2 as histological healing. Most authors have considered both lymphocytic infiltration and crypt hyperplasia as lacking specificity.[11,17,20,23,26,31–35] However, the data on the outcomes of non-atrophic lesions in patients with CD have been poor and conflicting,[10,20] particularly because there are insufficient studies on coeliac patients after GFD.[35] For this reason, we believe that the absence of villous atrophy and crypt hyperplasia in presence of normal lymphocytic infiltrate is truly representative of histological healing, according to the standardised classification (Marsh modified by Oberhuber).[1,3]

Another peculiar aspect of our study is that we enrolled only adult CD patients. Many studies have considered both adults and children.[10,17,19,20,32] However, intestinal histological healing in children after GFD has been shown to occur earlier and to a greater extent than in adults, with a complete histological recovery of 95%.[11,19,20,25] We believe that the enrolment of both children and adults in the same study may be misleading, ultimately resulting in an overestimation of the complete histological recovery.

Coeliac antibody positivity has been described as both linked[22,25] and not linked[12,27,28] to GFD adherence. In our study, serum antibodies (Ab tTG IgA and/or EMA) were positive after 1 year in patients with adequate and inadequate adherence to GFD, with overlapping percentages (29.7% and 30%). This result suggests that evaluating serum antibodies during GFD does not clearly distinguish patients with adequate GFD adherence from those with inadequate adherence.

Several studies have shown that antibody positivity after the start of GFD is more frequently associated with intestinal damage;[17,25,27] moreover, antibody negativity is not necessarily related to histological recovery and may in fact be associated with false-negative results.[7,10,11,19,22,25,27] In our study, antibody seroconversion after 1 year of GFD did not always indicate a complete resolution of the histological damages because seroconversion was evident in 64.7% of patients with partial histological recovery. In addition, the antibodies were still positive in 24.1% of patients with complete recovery of histological damage; this percentage was not different from that of patients with partial histological recovery (24.1% vs. 35.3%, P = 0.309). This finding confirms the possibility of antibody positivity in patients with complete mucosal recovery, as previously reported.[6,10,27] Thus, the determination of antibodies as a surrogate marker of histological healing and GFD adherence should be used with caution.

Symptom evaluation after 1 year of adequate adherence to GFD shows that well-being is obtained in a higher percentage of patients with complete histological recovery (91.5%) than in patients with partial histological recovery (76.5%), although these values are not significantly different. This result suggests that symptom resolution after 1 year of adequate adherence to GFD is not strictly associated with complete histological recovery. This finding is consistent with those of other studies reporting that, despite clinical improvements during GFD, histological damage may persist because clinical well-being is observed after a few months of GFD, though complete histological recovery takes more time.[6,13,14,26]

A lack of adequate adherence to GFD has been described as the most common cause of persistent symptoms in CD.[25,36] In fact, this study shows a highly significant persistence of clinical symptoms among patients whit inadequate adherence to the diet compared with those with adequate adherence (P = 0.0001). Our study confirms that persistence of symptoms may be indicative of an inadequate adherence to GFD.

Our results show that after 1 year of GFD, the BMD and biochemical/nutritional parameters were not significantly different between patients with partial and complete histological recoveries. Previous studies assessing the effect of GFD on BMD and biochemical/nutritional parameters have shown that after the beginning of GFD, there is a gradual improvement in these parameters that may not align with the histological recovery.[37,38] These data suggest that even nutritional parameters may not be reliable markers to assess recovery from histological damage.

The factors that influence histological healing in coeliac patients on GFD include age at diagnosis,[16,19–21,32] severity of histological damage,[16,20,21,26] gender,[16,32] duration[21,26,32] and adherence to GFD.[16,32] In our study, we used a logistic regression model to evaluate the reported risk factors for a lack of complete histological recovery. A higher degree of histological damage at diagnosis (Marsh 3C) emerged as the only significant influence. According to our results, patients with more severe histological damage at diagnosis will have a longer histological recovery time suggesting that in adult coeliac patients, despite a strict adherence to GFD, severe damage may require longer than 1 year for complete recovery. Consequently, the repetition of the gastroscopic and histological assessment should be delayed to 18–24 months.

Considering the significant association between persistent histological damage and the risk of lymphoproliferative malignancies,[26,39] an important conceptual question should be asked of our study. How should we consider patients with a partial histological recovery after 1 year of adequate GFD? For instance, such patients could be considered ‘slow responders’,[10,13,26,31,32,39] exhibiting a gradual healing process without risks of malignant complications, or ‘histologically refractory’,[10,13] reflecting the persistence of histological damage and consequent risk for malignant complications. Although, the present study is not able to settle this question because it was designed to obtain data on the first year of follow-up, it should be kept in mind that no agreement exists regarding the best timing for repeated gastroscopic/histological testing in coeliac patients. This lack of agreement is even less clear in patients who do not achieve complete histological recovery after beginning GFD. Therefore, the present results suggest further research into establishing an optimal timing for repeated gastroscopic/histological assessments in coeliac patients.

In conclusion, this prospective study shows that after 1 year of GFD adherence among adult patients completing a validated dietary questionnaire, complete histological recovery was obtained in two-thirds of the subjects. Furthermore, patients with more severe histological damage (Marsh 3C) at diagnosis are at greater risk for incomplete histological recovery at the 1 year.

Nancy A. Melville
May 21, 2015

LEIPZIG, Germany — In children with celiac disease, immunologic response to the hepatitis B vaccine is impaired, and neither a gluten-free diet nor boosters appear to improve that, according to new research presented here at the 33rd Annual Meeting of the European Society for Paediatric Infectious Diseases.

“This response should be evaluated at diagnosis,” said Maria José Pérez, MD, from Henares Hospital in Coslada, Spain.

Although previous studies have shown this reduced response, most have been limited by low numbers of patients with celiac disease and even lower numbers of control patients, Dr. Pérez explained.

Gluten has been implicated in the impaired response, and two studies have shown a response to the hepatitis B vaccine similar to that in the general population after patients switch to a gluten-free diet.

In their study, Dr. Pérez and her colleagues assessed the immune response to the vaccine in children with celiac disease. The team evaluated 214 children with celiac disease and 346 control patients who had completed the hepatitis B vaccine regimen in the first year of life. All patients were vaccinated before gluten was introduced into their diets.

Antibody titers were measured for each child to determine response to the vaccine. Nonresponse was defined as a level of hepatitis B surface antibody below 10 mUI/mL.

Overall, nonresponse was higher in children with celiac disease than in control subjects (68.7% vs 60.7%). For children younger than 5 years, this difference was significant (50.0% vs 30.1%; P = .015).

Table. Children With Undetectable Hepatitis B Surface Antibody

In children with celiac disease, the researchers found no relation between level of antibody and time since the last intake of gluten.

“Gluten intake has no role in the genesis of suboptimal immunologic response to hepatitis B vaccine in patients with celiac disease,” Dr. Pérez reported.

Over time, levels of antibody decreased in both groups. “When evaluating serologic response to hepatitis B vaccine, time elapsed since vaccination should be considered,” she said.

In another study, Dr. Pérez and a different team of researchers looked at the role of human leukocyte antigen genes in vaccine response. Previous studies have identified these genes as the main marker for lack of response to the hepatitis B vaccine, so the team looked at the association in children with celiac disease.

The study involved 188 children with celiac disease and 204 healthy control subjects.

The rate of responders to the vaccine was significantly lower in children with the human leukocyte antigen DR3 gene than in those without (22.41% vs 47.56%; P < .001). And the rate of undetectable levels of antibody was higher in children with the human leukocyte antigen DQ2 gene than in those without (13.96% vs 3.91%; P = .002). "DQ2 and DR3 expression is associated with an impaired immunologic response to hepatitis B vaccine," Dr. Pérez reported. In another study by another team led by Dr. Pérez, researchers assessed the effectiveness of a booster vaccine. Hep B Booster
The prospective study involved 72 children with celiac disease who were vaccinated in the first year of life and whose antibody levels were below 10 mUI/mL.

The researchers found no change in levels after the children received a single booster.

“A single booster dose of hepatits B vaccine is not effective in achieving an adequate immune response,” especially in children with undetectable levels of antibody, the researchers report.

Children with celiac disease and undetectable levels of antibody should be revaccinated with the complete immunization regimen, they advise.

But antibodies alone might not tell the whole story in terms of response to the vaccine, said Joseph Murray, MD, from the Mayo Clinic in Rochester, Minnesota.

“Protection from hepatitis B is likely not dependent on antibodies alone,” he told Medscape Medical News. “It also involves T-cell response, so the lack of measurable antibodies is not absolute proof of no protection.”

However, the findings support previous research on the poor response to vaccine in children with celiac disease, said Dr. Murray, who is coauthor of a recent report on celiac disease (Clin Gastroenterol Hepatol. Published online July 19, 2014).

“The data are generally consistent with previous data on the genetic association between DQ2 genetics and poor response to hep B vaccine,” he said.

Dr. Murray said he considers such evidence when managing his patients of all ages.

“I routinely test for hepatitis B response in vaccinated celiac patients, especially if they are younger or work in exposure-risk settings, such as healthcare or corrections,” he said.

“If they don’t have a response to a single booster, I recommend they redo the vaccine after 1 year of a gluten-free diet, based on previous studies that suggest active disease impairs response.”

The researchers report no relevant financial relationships. Dr. Murray is editor of the book, Mayo Clinic Going Gluten Free.

33rd Annual Meeting of the European Society for Paediatric Infectious Diseases (ESPID): Abstracts 463 and 464 and poster MPW06. Presented May 15, 2015.