Prevalence of celiac disease in Tunisia: mass-screening study in schoolchildren

Abstract

Background: Celiac disease is reported to be common among North Africans, particularly Tunisians. Nevertheless, the prevalence of coeliac disease in the general population has not been previously investigated.

Objective: This study aimed to determine the prevalence of celiac disease among children in Tunisia and to describe the clinical profile of the screened patients.

Methods: A mass screening study based on drawing lots was carried out on schoolchildren in Ariana, a Tunisian district. A participation agreement was obtained from 6286 children (3175 boys, age: 9.7+/-3 years). Two children of known celiac disease were present in this population. All participants were tested for IgA antitissue transglutaminase antibodies (IgA-tTG) by a commercial enzyme-linked immunosorbent assay (ELISA) and total IgA levels. Sera, found positive by the initial screening, were assessed by immunofluorescence for the presence of IgA antiendomysium antibodies (IgA-AE). Positive participants were also called in for serological control, intestinal biopsy, biological exploration (hemoglobin rate, calcemia and albuminemia) and bone mineral densitometry.

Results: Among the 6284 participants, 139 (1/45) were positive for IgA-tTG. Forty-two of these had low-level IgA-tTG and no one had IgA deficiency. IgA-AE was detected in 40 participants. One hundred and seven children were called in, 28 had both positive tests (IgA-tTG +/IgA-AE+) and 79 were only positive for IgA-tTG (IgA-tTG +/IgA-AE-). Intestinal biopsy was performed in the 28 participants of the first group (IgA-tTG +/IgA-AE+) and confirmed celiac disease in 26 cases. In the second group (IgA-tTG +/IgA-AE-), intestinal biopsy was performed in 26 children and histological examination was normal in all cases. Among the 26 biopsy-proven celiac disease children, six (23%) had typical clinical symptoms of celiac disease, whereas the others had atypical forms with 11 (42%) asymptomatic. In 23 biopsy-proven celiac disease children, bone mineral density was significantly lower than that of a group of 109 normal children (0.850+/-0.06 g/cm2 versus 0.912+/-0.06 g/cm2, P<0.05). Seven participants (30.4%) among the celiac disease children and six (7.5%) among the controls had a total-body Z score for bone mineral density of <-2 (P<0.001).

Conclusion: The prevalence of celiac disease in Tunisian schoolchildren, estimated to be about 1/157, is close to the European prevalence. Most of the screened children showed an atypical and asymptomatic form, but even the typical forms were underdiagnosed. Ostopenia was frequently observed in celiac disease patients.