Screening of the adult population in Iran for coeliac disease: comparison of the tissue-transglutaminase antibody and anti-endomysial antibody tests

Recent insights in the epidemiology of autoimmune diseases: improved prevalence estimates and understanding of clustering of diseases

Previous studies have estimated a prevalence of a broad grouping of autoimmune diseases of 3.2%, based on literature review of studies published between 1965 and 1995, and 5.3%, based on national hospitalization registry data in Denmark. We examine more recent studies pertaining to the prevalence of 29 autoimmune diseases, and use these data to correct for the underascertainment of some diseases in the hospitalization registry data. This analysis results in an estimated prevalence of 7.6-9.4%, depending on the size of the correction factor used. The rates for most diseases for which data are available from many geographic regions span overlapping ranges. We also review studies of the co-occurrence of diseases within individuals and within families, focusing on specific pairs of diseases to better distinguish patterns that may result in insights pertaining to shared etiological pathways. Overall, data support a tendency for autoimmune diseases to co-occur at greater than expected rates within proband patients and their families, but this does not appear to be a uniform phenomenon across all diseases. Multiple sclerosis and rheumatoid arthritis is one disease pair that appears to have a decreased chance of coexistence.

Prevalence of celiac disease among patients with Behcet's disease in Iran

BACKGROUND

Behcet's disease and Celiac disease, both common in Iran, share many immunopathogenic and clinical features. Based on the possible association between these two diseases, this study is designed to determine the frequency of non-diagnosed celiac disease in patients with Behcet's disease.

METHODS

The sera of 288 consecutive patients with Behcet's disease were screened with anti-endomysial antibody and anti-tissue transglutaminase antibody for celiac disease. Those with a positive test underwent upper gastrointestinal endoscopy and duodenal biopsies to confirm the diagnosis of celiac disease. The patients with celiac disease were put on a gluten free diet to evaluate its efficacy on the improvement of their lesions.

RESULTS

Fourteen patients had positive anti-tissue transglutaminase antibody test (two with positive anti-endomysial antibody as well). Duodenal biopsies showed findings compatible with Marsh 3 in one and Marsh 1 in three other patients. All the diagnosed patients with celiac disease responded to the gluten free diet.

CONCLUSION

Our findings didn't support any association between celiac disease and Behcet's disease in Iranian patients compared to the general population of Iran.

Gluten sensitivity enteropathy in patients with recurrent aphthous stomatitis

Background

Gluten sensitive enteropathy (GSE) is an autoimmune enteropathy triggered by the ingestion of gluten-containing grains in susceptible individuals. Recurrent aphthous stomatitis (RAS) may be the sole manifestation of GSE. The aim of this study was to determine the prevalence of gluten sensitivity enteropathy (GSE) in a large group of patients with RAS and assess the efficacy of gluten free diet (GFD) on the improvement of aphthous lesions in those who were diagnosed with GSE.

Methods

Two hundred and forty seven patients with RAS were included. The patients had at least three aphthous attacks per year. Patients were screened by IgA anti-endomysial antibody (EMA), IgA anti tissue transglutaminase (TTG) and serum IgA level. Those with a positive serology underwent endoscopic biopsies of the duodenal mucosa and patients with negative serology were excluded. The diagnosis of GSE was based on a positive serological test and abnormal duodenal histology. For patients with GSE, gluten free diet was recommended.

Results

Six out of 247 RAS patients had positive TTG test alone, and one had positive EMA and TTG. All 7 patients with positive serologic tests underwent duodenal biopsies. Histological findings were compatible with GSE in all of them (Marsh I in four patients, Marsh II in two patients and Marsh IIIB in one another.). The mean age of GSE patients was 27.42 ± 10.56 (range, 13 to 40) years old. They were suffering from RAS for an average duration of 4.5 years. All of the 7 GSE patients had not responded to the routine anti-aphthae medications, including topical corticosteroids, tetracycline and colchicine. Four patients who adhered to a strict gluten-free diet showed noticeable improvement in their aphthous lesions over a period of 6 months.

Conclusion

A significant minority (e.g. 2.83%) of RAS patients have GSE. This could be compared with the 0.9% prevalence of GSE in the general population of Iran. This study suggests that evaluation for celiac disease is appropriate in patients with RAS. Additionally, the unresponsiveness to conventional anti-aphthae treatment could be an additional risk indicator.

Screening for celiac disease in diabetic children from Iran

Celiac disease has been shown to be associated with type 1 diabetes mellitus. We conducted this study to determine the frequency of celiac disease in a group of Iranian diabetic children. Ninety-six patients with type 1 diabetes mellitus were tested for anti-tissue transglutaminase antibodies. Six patients (6.25%) were seropositive, and histopathological changes were compatible with celiac disease in intestinal biopsy.

Impact of mass screening for gluten-sensitive enteropathy in working population

AIM: To assess: (1) frequency and clinical relevance of gluten sensitive enteropathy (GSE) detected by serology in a mass screening program; (2) sensitivity of antitransglutaminase (tTGA) and antiendomysium antibodies (EmA); and (3) adherence to gluten-free diet (GFD) and follow-up.

METHODS: One thousand, eight hundred and sixty-eight subjects recruited from an occupational health department underwent analysis for tTGA and EmA and, if positive, duodenal biopsy, DQ2/DQ8 genotyping, clinical feature recording, blood tests, and densitometry were performed. Since > 98% of individuals had tTGA < 2 U/mL, this value was established as the cut-off limit of normality and was considered positive when confirmed twice in the same sample. Adherence to a GFD and follow up were registered.

RESULTS: Twenty-six (1.39%) subjects had positive tTGA and/or EmA, and 21 underwent biopsy: six Marsh III (one IIIa, four IIIb, one IIIc), nine Marsh I and six Marsh 0 (frequency of GSE 1:125). The sensitivity of EmA for GSE was 46.6% (11.1% for Marsh I, 100% for Marsh III), while for tTGA, it was 93.3% (88.8% for Marsh I, 100% for Marsh III). All 15 patients with abnormal histology had clinical features related to GSE. Marsh I and III subjects had more abdominal pain than Marsh 0 (P = 0.029), and a similar trend was observed for distension and diarrhea. No differences in the percentage of osteopenia were found between Marsh I and III (P = 0.608). Adherence to follow-up was 69.2%. Of 15 GSE patients, 66.7% followed a GFD with 80% responding to it.

CONCLUSION: GSE in the general population is frequent and clinically relevant, irrespective of histological severity. tTGA is the marker of choice. Mass screening programs are useful in identifying patients who can benefit from GFD and follow-up.

Gluten sensitive enteropathy in patients with iron deficiency anemia of unknown origin

AIM: To determine the prevalence of gluten sensitive enteropathy (GSE) in a large group of patients with iron deficiency anemia (IDA) of obscure origin.

METHODS: In this cross-sectional study, patients with IDA of obscure origin were screened for GSE. Anti-endomysial antibody (EMA) and tissue transglutaminase antibody (tTG) levels were evaluated and duodenal biopsies were taken and scored according to the Marsh classification. The diagnosis of GSE was based on a positive serological test and abnormal duodenal histology. Gluten free diet (GFD) was advised for all the GSE patients.

RESULTS: Of the 4120 IDA patients referred to our Hematology departments, 206 (95 male) patients were found to have IDA of obscure origin. Thirty out of 206 patients (14.6%) had GSE. The mean age of GSE patients was 34.6 ± 17.03 (range 10-72 years). The female to male ratio was 1.3:1. Sixteen patients had Marsh 3, 12 had Marsh 2, and 2 had Marsh 1 lesions. The severity of anemia was in parallel with the severity of duodenal lesions. Twenty-two GSE patients (73.3%) had no gastrointestinal symptoms. Fourteen GSE patients who adhered to GFD without receiving iron supplementation agreed to undergo follow up visits. After 6 mo of GFD, their mean hemoglobin levels (Hb) increased from 9.9 ± 1.6 to 12.8 ± 1.0 g/dL (P < 0.01). Interestingly, in 6 out of 14 patients who had Marsh 1/2 lesions (e.g. no villous atrophy) on duodenal biopsy, mean Hb increased from 11.0 ± 1.1 to 13.1 ± 1.0 g/dL (P < 0.01) while they did not receive any iron supplementation.

CONCLUSION: There is a high prevalence (e.g. 14.6%) of GSE in patients with IDA of obscure origin. Gluten free diet can improve anemia in GSE patients who have mild duodenal lesions without villous atrophy.

Prevalence of celiac disease in Shiraz, southern Iran

BACKGROUND/AIM

This study was performed to evaluate the prevalence of celiac disease (CD) in Shiraz, southern Iran.

MATERIALS AND METHODS

Serum samples were collected from 1440 persons (age range = 20-83 years, mean age = 45.4 years) in 2004 and screened for endomysial and tissue transglutaminase antibodies. A questionnaire was completed for all subjects in relation to gastrointestinal (GI) symptoms and cases with positive serology were requested to undergo small-bowel biopsy.

RESULTS

Seven cases (0.5%) were positive for IgA anti-tissue transglutaminase (anti-tTG), and only two (0.14%) were positive for IgA anti-endomysial antibody (anti-EMA), both of whom had highly positive anti-tTg levels (40.4 and 48.0 IU/l). The major clinical symptoms of CD, such as recurrent abdominal pain and change in bowel habits were present in all patients with positive anti-tTG assays. Only five subjects with positive serology agreed to undergo upper GI endoscopy and duodenal biopsy. Three of these cases were reported with Marsh I histologic findings, while in the two cases with positive serologic anti-EMA, more advanced forms of CD were present.

CONCLUSION

The prevalence of CD in apparently healthy adults was lower than the reported series from northern parts of the country; therefore, we suggest a more long-term follow-up study in high-risk groups, especially in the apparently healthy subjects in our region.

Nutritional deficiencies in celiac disease

Celiac disease is characterized by small bowel enteropathy, precipitated in genetically susceptible individuals by the ingestion of "gluten," which is a term used to encompass the storage proteins of wheat, rye, and barley. Although the intestine heals with removal of gluten from the diet, the intolerance is permanent and the damage recurs if gluten is reintroduced. This damage causes a wide variety of consequence including maldigestion and malabsorption, resulting in the characteristic, although not universal, features of malnutrition. This article examines recent advances in the understanding of the spectrum of celiac disease, illustrates the impact of celiac disease on nutrition, and describes approaches to the management of the disease.

Adult population screening for coeliac disease: comparison of tissue-transglutaminase antibody and anti-endomysial antibody tests

Serological screening tests for coeliac disease have significantly advanced the diagnosis of this condition. The very high specificity (almost 100%) of anti-endomysial antibody detection has been repeatedly confirmed, whereas a lower specificity (90-95%) is found with anti-tissue transglutaminase antibody assays. In the study by Malekzadeh and colleagues, a group of study participants were identified with raised anti-tissue transglutaminase antibodies, but the endomysial antibody test was negative in 86%. Although many of these participants were found to have raised intra-epithelial lymphocytes in their small intestinal mucosa, there is currently insufficient evidence to confidently diagnose gluten-sensitive disease in these patients. Hence, their report that a minimum prevalence of 1:104 of gluten sensitivity is found in the general population of Iran is likely to be an over-estimate and requires confirmation.