Diagnostic significance of HLA-DQ typing in patients with previous coeliac disease diagnosis based on histology alone

A single nucleotide polymorphism genetic risk score to aid diagnosis of coeliac disease: a pilot study in clinical care

BACKGROUND

Single nucleotide polymorphism-based genetic risk scores (GRS) model genetic risk as a continuum and can discriminate coeliac disease but have not been validated in clinic. Human leukocyte antigen (HLA) DQ gene testing is available in clinic but does not include non-HLA attributed risk and is limited by discrete risk stratification.

AIMS

To accurately characterise both HLA and non-HLA coeliac disease genetic risk as a single nucleotide polymorphism-based GRS and evaluate diagnostic utility.

METHODS

We developed a 42 single nucleotide polymorphism coeliac disease GRS from a European case-control study (12 041 cases vs 12 228 controls) using HLA-DQ imputation and published genome-wide association studies. We validated the GRS in UK Biobank (1237 cases) and developed direct genotyping assays. We tested the coeliac disease GRS in a pilot clinical cohort of 128 children presenting with suspected coeliac disease.

RESULTS

The GRS was more discriminative of coeliac disease than HLA-DQ stratification in UK Biobank (receiver operating characteristic area under the curve [ROC-AUC] = 0.88 [95% CIs: 0.87-0.89] vs 0.82 [95% CIs: 0.80-0.83]). We demonstrated similar discrimination in the pilot clinical cohort (114 cases vs 40 controls, ROC-AUC = 0.84 [95% CIs: 0.76-0.91]). As a rule-out test, no children with coeliac disease in the clinical cohort had a GRS below 38th population centile.

CONCLUSIONS

A single nucleotide polymorphism-based GRS may offer more effective and cost-efficient testing of coeliac disease genetic risk in comparison to HLA-DQ stratification. As a comparatively inexpensive test it could facilitate non-invasive coeliac disease diagnosis but needs detailed assessment in the context of other diagnostic tests and against current diagnostic algorithms.

First-degree Relatives of Celiac Disease Patients Have Increased Seroreactivity to Serum Microbial Markers

Risk of celiac disease (CD) is increased in relatives of CD patients due to genetic and possible environmental factors. We recently reported increased seropositivity to anti-Saccharomyces cerevisiae (ASCA), Pseudomonas fluorescens-associated sequence (anti-I2) and Bacteroides caccae TonB-linked outer membrane protein (anti-OmpW) antibodies in CD. We hypothesized these markers also to be overrepresented in relatives. Seropositivity and levels of ASCA, anti-I2 and anti-OmpW were compared between 463 first-degree relatives, 58 untreated and 55 treated CD patients, and 80 controls. CD-associated human leukocyte antigen (HLA)-haplotypes and transglutaminase (tTGab) and endomysium (EmA) antibodies were determined. One or more of the microbial antibodies was present in 75% of relatives, 97% of untreated and 87% of treated CD patients and 44% of the controls. The relatives had higher median ASCA IgA (9.13 vs. 4.50 U/mL, p < 0.001), ASCA IgG (8.91 vs. 5.75 U/mL, p < 0.001) and anti-I2 (absorbance 0.74 vs. 0.32, p < 0.001) levels than controls. There was a weak, positive correlation between tTGab and ASCA (r = 0.31, p < 0.001). Seropositivity was not significantly associated with HLA. To conclude, seropositivity to microbial markers was more common and ASCA and anti-I2 levels higher in relatives of CD patients than controls. These findings were not associated with HLA, suggesting the role of other genetic and environmental factors.

Association between HLA alleles and risk of celiac disease in Iranian patients

Celiac disease (CD) is a common autoimmune disease that is manifested by inflammation of the small intestine and varying extra intestinal symptoms, also considered to be associated with human HLA-DQ genes. In this study, 40 patients of CD and 40 healthy control samples were genotyped for HLA-DQB1 and 14 patients of CD and 14 healthy control samples were genotyped for HLA-DQA1genes using the SSP-PCR technique and a commercial kit.The DQA1*05 allele had the highest frequency among the patient group (42.86%). The frequency of this allele was 28.57% in healthy controls, and there was no statistically significant difference in this case (p= 0.771).The DQB1*02 allele was the most common in patients (33.75%) followed by the DQB1*03 allele (31.25%).The difference in frequency of the HLA-DQB1*02 allele in the patient and control groups was statistically significant (P= 0.0002, OR = 4.72). The remarkable differences in the distribution of HLA-DQ2 in Iranian patients compared to controls and relative risks signified the role of these alleles in the development of CD in Iranian patients and confirmed the likelihood of using HLA-DQ typing in the substantiation of the disease.

The Phenotype of Celiac Disease Has Low Concordance between Siblings, Despite a Similar Distribution of HLA Haplotypes

The factors determining the presentation of celiac disease are unclear. We investigated the phenotypic concordance and the distribution of human leukocyte antigen (HLA) risk haplotypes in affected siblings. One hundred sibling pairs were included. Clinical and histological parameters and HLA haplotypes were compared between the first diagnosed indexes and their siblings. The phenotype was categorized into gastrointestinal, extra-intestinal, malabsorption/anemia, and asymptomatic. The phenotype was fully concordant in 21 pairs. The most common concordant phenotype was gastrointestinal (14 pairs). Indexes had more anemia/malabsorption and extra-intestinal symptoms than siblings (45% vs. 20%, p < 0.001 and 33% vs. 12%, p < 0.001, respectively). Twenty siblings and none of the indexes were asymptomatic. The indexes were more often women (81% vs. 63%, p = 0.008). They were also more often seronegative (11% vs. 0%, p = 0.03) and younger (37 vs. 43 year, p < 0.001), and had more severe histopathology (total/subtotal atrophy 79% vs. 58%, p = 0.047) at diagnosis. The indexes and siblings were comparable in other disease features. Pairs with discordant presentation had similar HLA haplotypes more often than the concordant pairs. The phenotype was observed to vary markedly between siblings, with the indexes generally having a more severe presentation. HLA did not explain the differences, suggesting that non-HLA genes and environmental factors play significant roles.

HLA-DQ2 and -DQ8 haplotypes frequency and diagnostic utility in celiac disease patients of Gaza strip, Palestine

Purpose

Celiac disease (CD) diagnosis can be established by serological and small bowel biopsy (SBB), while absence of HLA-DQ2 and -DQ8 haplotypes excludes the disease. The present study aims at evaluating the diagnosis of a representative sample of pediatric and adult CD patients of Gaza strip in light of DQ2 and DQ8 haplotypes expression.

Methods

Unrelated CD patients (n = 101) and matched healthy controls (n = 97) were genotyped for DQA1*05, DQB1*02 and DQB1*03:02 alleles by allele-specific real-time PCR. The diagnosis was re-evaluated according to the patient laboratory tests and HLA-DQ genotype.

Results

The diagnosis of 35 patients who have been managed for CD could not be confirmed. Twenty-five of them were diagnosed upon their clinical presentation only. The remaining were either negative for serological and SBB tests or negative for HLA-DQ haplotypes. The HLA-DQ alleles were negative in 4 SBB and one Anti-EMA positive patients. The frequency of DQ2 and DQ8 haplotypes among the remaining 65 confirmed cases was 70.8 and 15.4%, respectively, compared to 17.5 and 27.8% in the controls. The DQB1*02 allele was the most common in the cases (84.6%) followed by DQA1*05 allele (80%) and DQB1*03:02 allele (20%). The DQA1*05 allele was commonest in the control group (54.6%) followed by DQB1*02 allele (42.3%) and DQB1*03:02 allele (28.9%).

Conclusions

Absence of HLA-DQ2 and HLA-DQ8 genotyping in the workup of patients may result in CD misdiagnosis, particularly in a setting with poor histopathological diagnostic capacity.

The potential usefulness of human leukocyte antigen typing for celiac disease screening: A systematic review and meta-analysis

BACKGROUND AND AIM

The presence of specific human leukocyte antigen-DQ2 and DQ8 seems to be necessary for celiac disease development, but the real contribution of its typing for screening is still uncertain. We aim to conduct a systematic review and meta-analysis of the diagnostic performance of human leukocyte antigen typing tests for celiac disease screening.

METHODS

Systematic review of published studies assessing accuracy of human leukocyte antigen DQ2 and DQ8 typing for the detection of celiac disease were selected. MEDLINE and EMBASE were searched from 1st January 2004 until 31st December 2013. Two independent researchers carried out selection and classification of studies, data extraction and analysis. Meta-analysis combining sensitivities, specificities and likelihood ratios of HLA-DQ2 and DQ8 for the diagnosis of celiac disease were carried out.

RESULTS

6 studies including 1303 individuals were finally evaluated. Pooled sensitivity was 98% (95% confidence interval: 97-99). Overall specificity was 45% (95% confidence interval: 41-48). Regarding specificity, studies were heterogeneous and a subgroup analysis was done according to the type of population included. Overall negative likelihood ratio was 0.05 (0.03-0.09).

CONCLUSIONS

Due to its great sensitivity and low negative likelihood ratio, human leukocyte antigen-DQ2/DQ8 typing would be an appropriate test for ruling out celiac disease in the general population suffering related symptoms, and even more in at risk population.

Clinical utility of celiac disease-associated HLA testing

BACKGROUND

Negative predictive value (NPV) of celiac disease (CD)-related human leukocyte antigens (HLA) DQ2 and DQ8 approaches 100 % in individual patients. However, studies evaluating its exclusionary utility in patient groups are lacking.

AIM

We aim to assess the performance of HLA testing when applied to patient groups with varying characteristics and propose evidence-based recommendations for its clinical use.

METHODS

Demographic and clinical information was recorded in patients undergoing HLA testing. Using predetermined criteria, patients were classified as CD, non-CD, or indeterminate. Diagnostic yield of HLA testing was defined as the percentage of patients in whom CD could be excluded based on negative HLA test.

RESULTS

Two hundred and fifty-six patients underwent testing for CD-related HLA DQ2 and DQ8. 102 (100 non-CD, 2 CD) patients tested HLA negative for a 98 % NPV and 39 % diagnostic yield. Diagnostic yield was highest (60 %) in patients with intraepithelial lymphocytosis plus normal IgA tissue transglutaminase antibody (IgA-tTG) and lowest in patients with positive IgA-tTG plus villous atrophy (0 %). CD was diagnosed in two HLA-negative patients, who carried half of DQ2.5 trans genotype.

CONCLUSIONS

Diagnostic yield of CD-related HLA testing varies widely depending on clinical indication. HLA testing is a practical and valuable test for most patients in whom initial evaluation for CD is inconclusive. A negative HLA result usually obviates the need for further celiac testing including endoscopy and gluten challenge. Rarely, in patients reported as HLA negative, half of HLA DQ2.5 (cis or trans) is sufficient for development of CD.

Evaluation of HLA-DQ2/DQ8 genotype in patients with celiac disease hospitalised in 2012 at the Department of Paediatrics

Introduction

Celiac disease (CD) is a permanent intolerance to gluten that occurs in genetically predisposed individuals and leads to small intestinal mucosa damage. According to ESPGHAN guidelines from 2012, CD can be diagnosed in a patient with characteristic clinical symptoms, in whom, anti-tissue transglutaminase antibodies (> 10 times the upper limit) are found, endomysial antibodies (EMA) is confirmed and a positive genetic test is obtained. In these conditions no small-bowel biopsies are required.

Aim

Evaluation of the presence of HLA-DQ2 and HLA-DQ8 haplotypes in children with previously diagnosed CD, hospitalised in 2012 at the Department of Paediatrics and Immunology and/or the Gastroenterological Outpatient Clinic, and their relatives.

Material and methods

Blood samples of 22 subjects, including 9 children with CD diagnosed on the basis of clinical symptoms, serological investigations and small-intestine biopsy, 7 diagnosed on the basis of clinical symptoms and serological investigations, 2 with the suspicion of CD on the basis of clinical symptoms and 4 relatives of a child with CD. Methods: HLA-DQ2/DQ8 test, automatic evaluation by EUROArrayScan.

Results

The presence of HLA-DQ2 and/or HLA-DQ8 genotype was confirmed in 16 children with CD diagnosed on the basis of clinical symptoms and serological tests with/without intestinal biopsy, in 2 with the suspicion of CD and in 1 relative of a celiac child.

Conclusions

The evaluation of HLA-DQ2/DQ8 haplotype confirms the genetic predisposition to CD in subjects with the disease diagnosed previously on the basis of clinical symptoms, serological tests or intestinal biopsy. Genetic testing is particularly indicated for the diagnosis of CD in infants consuming gluten for a short time and in small amounts.

[Lymphocytic duodenosis: etiological study and clinical presentations]

INTRODUCTION

Lymphocytic duodenosis (LD) is a characteristic lesion in the initial phases of celiac disease (CD) but can be associated with many other entities. The aim of this study was to evaluate the prevalence of distinct causes of LD and possible differences in clinical presentation according to etiology.

METHODS

A retrospective study was performed that included 194 patients diagnosed with LD (more than 25 intraepithelial lymphocytes per 100 epithelial cells). A preestablished strategy to evaluate the cause of the disease was followed that included celiac serology (antitransglutaminase antibodies), HLA-DQ2/DQ8 genotypes, diagnosis of Helicobacter pylori and small intestinal bacterial overgrowth (SIBO). Diagnosis of CD was established on the basis of clinical and histological response to a gluten-free diet in patients with positive serology or compatible findings on HLA-DQ2 (at least one of the alleles) or -DQ8 (both alleles) study.

RESULTS

The most frequent cause of LD was CD (39%), followed by SBBO (22%), H.pylori (14%), CD and SIBO (12%), and other causes (13%). Most of the patients (83%) had a compatible HLA-DQ2 or -DQ8 genotype. In these patients, the most frequent diagnosis was CD (46%), while in the absence of HLA-DQ2/DQ8, the most frequent diagnoses were SIBO (44%) and H. pylori (22%). CD was the most frequent diagnosis in patients referred for dyspepsia, diarrhea and anemia, while H. pylori was the most frequent diagnosis in patients with abdominal pain.

CONCLUSIONS

The most common causes of LD in our environment are CD, followed by SIBO and H. pylori infection.

Intramuscular vs intradermal route for hepatitis B booster vaccine in celiac children

AIM: To compare intradermal (ID) and intramuscular (IM) booster doses, which have been used in healthy and high risk subjects, such as healthcare workers, haemodialysis patients, human immunodeficiency virus patients, and renal transplant recipients unresponsive to initial hepatitis B vaccination, in celiac individuals.

METHODS: We conducted our study on 58 celiac patients, vaccinated in the first year of life, whose blood analysis had showed the absence of protective hepatitis B virus (HBV) antibodies. All patients had received the last vaccine injection at least one year before study enrolment and they had been on a gluten free diet for at least 1 year. In all patients we randomly performed an HBV vaccine booster dose by ID or IM route. Thirty celiac patients were revaccinated with recombinant hepatitis B vaccine (Engerix B) 2 μg by the ID route, while 28 celiac patients were revaccinated with Engerix B 10 μg by the IM route. Four weeks after every booster dose, the anti-hepatitis B surface (HBs) antibody titer was measured by an enzyme-linked immune-adsorbent assay. We performed a maximum of three booster doses in patients with no anti-HBs antibodies after the first or the second vaccine dose. The cut off value for a negative anti-HBs antibody titer was 10 IU/L. Patients with values between 10 and 100 IU/L were considered "low responders" while patients with an antibody titer higher than 1000 IU/L were considered "high responders".

RESULTS: No significant difference in age, gender, duration of illness, and years of gluten intake was found between the two groups. We found a high percentage of "responders" after the first booster dose (ID = 76.7%, IM = 78.6%) and a greater increase after the third dose (ID = 90%, IM = 96.4%) of vaccine in both groups. Moreover we found a significantly higher number of high responders (with an anti-HBs antibody titer > 1000 IU/L) in the ID (40%) than in the IM (7.1%) group, and this difference was evident after the first booster dose of vaccination (P < 0.01). No side effects were recorded in performing delivery of the vaccine by either the ID or IM route.

CONCLUSION: Our study suggests that both ID and IM routes are effective and safe options to administer a booster dose of HBV vaccine in celiac patients. However the ID route seems to achieve a greater number of high responders and to have a better cost/benefit ratio.

Spectrum of gluten-sensitive enteropathy in patients with dysmotility-like dyspepsia

BACKGROUND

Dysmotility-like dyspepsia symptoms are frequent in patients with gluten-sensitive enteropathy (GSE). Current data suggest that patients with mild enteropathy may be present with gluten-sensitive symptoms and complications.

AIM

To investigate the prevalence of GSE, including mild enteropathy, in patients with dysmotility-like dyspepsia symptoms.

METHODS

We retrospectively studied 142 patients who presented dysmotility-like dyspepsia symptoms and normal upper gastrointestinal endoscopy. Endoscopic duodenal biopsies were taken and processed using hematoxylin-eosin staining and CD3 immunophenotyping. In patients with enteropathy (number of intraepithelial lymphocytes greater than 25 per 100 enterocytes) we also performed coeliac serology (anti-tissue transglutaminase IgA) and HLA-DQ2/DQ8 genotyping. A gluten-free diet was offered if one of these markers was positive. The final GSE diagnosis was established based on clinical and histopathological response to the gluten-free diet after 18 months of follow-up.

RESULTS

Fifty-one patients (35.9%) had enteropathy; 4 (2.8%) Marsh type 3b, 24 (16.9%) Marsh type 3a, 3 (2.1%) Marsh type 2, and 20 (14.1%) Marsh type 1. A positive serology result was extremely low (6.7%) in mild enteropathy (Marsh type 1-3a) in contrast with Marsh type 3b patients (50%). Most patients with enteropathy had positive HLA DQ2 or -DQ8 genotyping (84.1%). Out of the 37 patients who started a gluten-free diet, 34 (91.9%) improved their symptoms, and 28 of 32 (87.5%) had a histopathological or serological response. A final GSE diagnosis was established in 28 of the 142 patients (19.7%).

CONCLUSION

Gluten-sensitive enteropathy can be a frequent and unsuspected cause of dysmotility-like dyspepsia.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE

Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immunemediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied.

METHODS

The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy.

RESULTS

Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain.

CONCLUSION

The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

[Gluten-sensitive enteropathy and functional dyspepsia]

Gluten-sensitive enteropathy (GSE) is increasingly diagnosed in adults. The symptoms of this disease can overlap with those of functional dyspepsia. The prevalence of GSE in dyspepsia has been reported to be 1.2-6.2% and could be higher if the entire spectrum of lesions related to gluten sensitivity, including lymphocytic enteropathy, is considered. Patients with dyspepsia secondary to GSE could be mistakenly diagnosed with functional dyspepsia unless upper gastrointestinal endoscopy is completed with duodenal biopsy and immunostaining for intraepithelial lymphocytes. A missed diagnosis could have major consequences in terms of morbidity and mortality and quality of life. Consequently, endoscopic study of patients with dyspepsia should be completed by duodenal biopsy when there are symptoms suggestive of GSE.

HLA-DQB1 Haplotypes and their Relation to Oral Signs Linked to Celiac Disease Diagnosis

Objectives:

Celiac disease (CD) is an autoimmune disorder that can be divided into typical and atypical forms. Atypical forms can show extraintestinal manifestations among which oral signs are very frequent. Considering that the pathogenesis of CD is related to a positivity to specific HLA-DQB1 haplotypes, we tested whether the presence of the HLA-DQB1*02 allele could be a hypothetical cause of the development of oral manifestations.

Subjects and Methods:

For this study was been examined the oral condition of 98 Sardinian patients, all affected by CD and all on a gluten-free diet for at least 1 year. Then was been determined each patient’s HLA-DQB1 haplotype and compared these results with clinical information.

Results:

The statistical analysis evidenced that the absence of the HLA-DQB1*02 allele predisposes to oral manifestations such as dental enamel defects (DED) and recurrent aphthous stomatitis (RAS) (Pvalue=5.98x10^-05, OR = 0.23, CI: (0.10 - 0.45) per each copy of the HLA allele).

Conclusions:

These results showed that the presence of the HLA-DQB1*02 allele influences the development of oral signs in a dose-dependent manner and also how the HLA haplotype connected to oral signs could have a fundamental role for the diagnosis of atypical forms of CD.

Reproducibility of the histological diagnosis of celiac disease

OBJECTIVE

A small intestinal biopsy is considered to be the gold standard for the diagnosis of celiac disease (CD). However, the assessment of small intestinal histology may vary between pathologists. Our aim was, therefore, to determine the interobserver variability in the histological diagnosis of CD.

MATERIAL AND METHODS

Biopsy specimens of 297 pediatric patients suspected of having CD were revised by a single experienced pathologist and compared to the original reports. Mucosal changes were scored using the Marsh classification. In patients with a discrepancy in diagnosis, clinical and serological data were used to determine the most probable diagnosis.

RESULTS

Although the interobserver variability for the Marsh classification was found to be moderate with a Kappa value of 0.486, the Kappa value for the diagnosis reached an almost perfect agreement (0.850). Nevertheless, in 22 patients a different diagnosis was made by the second observer. Interestingly, in this subgroup relatively more biopsies were classified to be of suboptimal quality. Based on clinical presentation, serology and follow-up, 19 of those patients truly had CD. In 14 of them the diagnosis was originally missed by the first observer while five cases were under-diagnosed by the second pathologist.

CONCLUSIONS

CD can be missed histologically due to assessment variation between pathologists. A final diagnosis of CD should be based on histology, serology as well as response to the diet.

HLA-DQ genotyping combined with serological markers for the diagnosis of celiac disease: is intestinal biopsy still mandatory?

OBJECTIVES

The aim of this study was to evaluate the value of HLA-DQ2/DQ8 allelic genotyping combined with serologic testing for the diagnosis of celiac disease (CD).

PATIENTS AND METHODS

One hundred seventy children, who underwent jejunal biopsy for digestive symptoms or malnutrition, were tested for HLA-DQ2/DQ8 and serologic markers (tTG and/or anti-endomysial antibodies). Children were classified in 2 groups, according to jejunal histology: group 1, when partial or total villous atrophy was associated with an increased intraepithelial lymphocytosis suggesting CD, and group 2, when these histological criteria were absent.

RESULTS

Eight children were excluded from the study because their intestinal histology was not informative; 82 children were classified in group 1 and 80 in group 2. Eighty-one of 82 children in group 1 were positive for HLA and serologic testing. The other child had negative HLA and serologic testing but marked villous atrophy, and further investigation showed an allergic disease. Among the 80 children in group 2, 53 were negative for both HLA and serologic testing, 22 were positive for HLA but negative for serologic testing, 2 were negative for HLA and positive for serologic testing, and 3 patients were positive for both HLA and serologic testing. The last 3 children were shown to have an autoimmune background and had probably a latent form of CD. The association of HLA-DQ2/DQ8 and serologic markers had a sensitivity of 98.8%, a specificity of 96.2%, a positive likelihood ratio of 26.3, and a negative likelihood ratio of 0.013.

CONCLUSIONS

The association of positive HLA-DQ2/DQ8 and serologic testing has a high predictive value for CD. We suggest that symptomatic children with high titers of immunoglobulin (Ig)A tTG could be diagnosed as patients with CD without performing jejunal biopsy. In other children, HLA-DQ2/DQ8 could be useful to exclude the diagnosis of CD if negative. In cases of low IgA tTG titers or in patients with IgA deficiency, intestinal biopsy remains mandatory.

Serological screening for coeliac disease in adults with Turner's syndrome: prevalence and clinical significance of endomysium antibody positivity

OBJECTIVE

To investigate the prevalence of coeliac disease (CD) in an adult population with Turner's syndrome (TS). Design A clinic population with TS was screened using a serological test for CD.

METHODS

Two hundred and fifty six patients with TS were included in the study. Five patients had existing diagnoses of CD. The remaining 251 asymptomatic patients were screened using an IgA endomysium antibody (EMA) test. Positive cases were offered endoscopy with duodenal biopsy. HLA typing was undertaken in existing cases and new EMA-positive cases.

RESULTS

Of the 251 patients screened, eight were found to be EMA positive (3.2%). Seven patients proceeded to duodenal biopsy on which all were confirmed histologically to have cluster of differentiation (2.8%). The prevalence of subclinical cluster of differentiation in the population can therefore be estimated between 2.8 and 3.2%. The total population prevalence of CD, including the previously diagnosed cases, is estimated between 4.7 and 5.1%. Ten patients with histologically confirmed cluster of differentiation underwent HLA typing of which eight were HLA-DQ2 positive, one was HLA-DQ8 positive and one was negative to both HLA-DQ2 and HLA-DQ8.

CONCLUSIONS

This study demonstrates an increased prevalence of cluster of differentiation in an adult population with TS over the general population. This is consistent with previous data published in paediatric populations.

HLA and autoimmune digestive disease: a clinically oriented review for gastroenterologists

OBJECTIVES

The human leukocyte antigen (HLA) system includes genes involved in graft-vs-host rejection and in immune response. The discovery that HLAs are associated with several diseases led to appealing developments both in basic biomedical research and in clinical medicine, and offered the opportunity to improve the understanding of pathogenesis and classification of diseases, as well as to provide diagnostic and prognostic indicators. The aim of this article is to review the association between HLA alleles and autoimmune digestive disease and its current relationship with modern HLA nomenclature and clinical practice.

METHODS

Articles dealing with the association between HLAs and autoimmune digestive disease (including celiac disease, inflammatory bowel disease, autoimmune hepatitis, sclerosing cholangitis and primary biliary cirrhosis) were searched for using Pubmed and SCOPUS databases from earliest records to January 2008.

RESULTS

The review has provided two sections. In the first, we explain the basic principles of HLA structure, function, and nomenclature, as an introduction to the second section, which describes current associations between HLA alleles and digestive diseases. The clinical implications of each HLA association are critically discussed. Actually, a clinical role for HLA typing is suggested for only a few conditions, e.g., celiac disease.

CONCLUSIONS

The knowledge of current HLA nomenclature and of its association with some digestive diseases such as celiac disease can be useful in clinical practice for diagnostic and prognostic purposes. This can avoid improper HLA typing as well as stressing the need for further studies on other possible clinical applications.

Gluten intake interferes with the humoral immune response to recombinant hepatitis B vaccine in patients with celiac disease

OBJECTIVE

Patients with celiac disease, who often carry human leukocyte antigen-DR3;DQ2, are prone to inadequate response to hepatitis B immunization. We evaluated vaccine response in relation to disease activity and whether previous treatment with a gluten-free diet influences the achievement of protective antibody titers.

PATIENTS AND METHODS

We studied 128 children and adolescents with celiac disease and 113 age-matched control subjects. Twenty-two patients with celiac disease were prospectively immunized after diagnosis during dietary treatment (group 1). A total of 106 (group 2) and the control subjects received vaccination by mass immunization in schools at 14 years of age regardless of diet status and when celiac disease was still undiagnosed in 27 of these children. Diet compliance and celiac disease activity were monitored by measurement of antibodies against transglutaminase and endomysium. Vaccine response was determined by measuring antihepatitis B antibodies from serum.

RESULTS

The seroconversion after hepatitis B vaccination was 95.5% in group 1. All of these patients carried human leukocyte antigen DQ2. The response rate in group 2 was 50.9% and correlated with gluten intake (untreated patients: 25.9%, non-strict diet: 44.4%, strict diet: 61.4%). Treated and compliant patients did not significantly differ from control subjects (75.2%). Thirty-seven antihepatitis B-negative patients with celiac disease received a booster during a controlled gluten-free diet, and 36 (97.3%) seroconverted, irrespective of the presence of human leukocyte antigen DQ2.

CONCLUSIONS

Nonresponse to recombinant hepatitis B surface antigen may be a sign of undiagnosed celiac disease. However, there is a good vaccine response in adequately treated patients. Human leukocyte antigen DQ alleles do not seem to have a primary role. Revaccination is recommended during a controlled gluten-free diet.

Gluten tolerance in adult patients with celiac disease 20 years after diagnosis?

BACKGROUND AND OBJECTIVE

Celiac disease (CD) is believed to be a permanent intolerance to gluten. A number of patients, however, discontinue the gluten-free diet (GFD) without developing symptoms or signs. The aim of our study was to investigate whether CD patients are capable of developing tolerance to gluten.

METHODS

All 77 adult patients from our hospital known to have biopsy-proven CD for more than 10 years were invited to participate. We investigated symptoms, gluten consumption, antibodies for CD and other autoimmunity, human leukocyte antigen (HLA)-typing, bone mineral density, and performed small bowel biopsies. Tolerance was defined as no immunological or histological signs of CD while consuming gluten.

RESULTS

Sixty-six patients accepted participation, but after review of the diagnostic biopsies 53 were found to have true CD. Twenty-three percent of patients had a gluten-containing diet, 15% admitted gluten transgression and 62% followed the GFD. Patients on a GFD had significantly more osteoporosis. Normal small bowel mucosa was found in four of eight on gluten-containing diet and in four of four with gluten transgression. Two patients were considered to have developed tolerance to gluten. One of them was HLA-DQ2/DQ8 negative.

CONCLUSION

Development of tolerance to gluten seems possible in some patients with CD. Further follow-up will show whether this tolerance is permanent or only a long-term return to latency. This feature may be associated with genetic characteristics, especially with HLA genotypes that differ from DQ2 or DQ8. More insight into the mechanisms of the development of gluten tolerance may help to distinguish those CD patients that might not require life-long GFD.

Haptoglobin polymorphism: a novel genetic risk factor for celiac disease development and its clinical manifestations

BACKGROUND

Haptoglobin (Hp) alpha-chain alleles 1 and 2 account for 3 phenotypes that may influence the course of inflammatory diseases via biologically important differences in their antioxidant, scavenging, and immunomodulatory properties. Hp1-1 genotype results in the production of small dimeric, Hp2-1 linear, and Hp2-2 cyclic polymeric haptoglobin molecules. We investigated the haptoglobin polymorphism in patients with celiac disease and its possible association to the presenting symptoms.

METHODS

We studied 712 unrelated, biopsy-proven Hungarian celiac patients (357 children, 355 adults; severe malabsorption 32.9%, minor gastrointestinal symptoms 22.8%, iron deficiency anemia 9.4%, dermatitis herpetiformis 15.6%, silent disease 7.2%, other 12.1%) and 384 healthy subjects. We determined haptoglobin phenotypes by gel electrophoresis and assigned corresponding genotypes.

RESULTS

Hp2-1 was associated with a significant risk for celiac disease (P = 0.0006, odds ratio [OR] 1.54, 95% CI 1.20-1.98; prevalence 56.9% in patients vs 46.1% in controls). It was also overrepresented among patients with mild symptoms (69.2%) or silent disease (72.5%). Hp2-2 was less frequent in patients than in controls (P = 0.0023), but patients having this phenotype were at an increased risk for severe malabsorption (OR 2.21, 95% CI 1.60-3.07) and accounted for 45.3% of all malabsorption cases. Celiac and dermatitis herpetiformis patients showed similar haptoglobin phenotype distributions.

CONCLUSIONS

The haptoglobin polymorphism is associated with susceptibility to celiac disease and its clinical presentations. The predominant genotype in the celiac population was Hp2-1, but Hp2-2 predisposed to a more severe clinical course. The phenotype-dependent effect of haptoglobin may result from the molecule's structural and functional properties.