Prevalence of Celiac Disease in Healthy Turkish School Children

OBJECTIVES: Epidemiological studies of celiac disease (CD) in Turkey have been performed only within some regions of the country. The aim of this study was to determine the prevalence of CD in Turkish school children. METHODS: Between 2006 and 2008, serum samples were collected from 20,190 students (age range, 6-17 years) in 139 schools in 62 cities from different regions of Turkey. CD was screened using IgA antitissue transglutaminase (IgA-tTG) and total serum IgA. Subjects with selective IgA deficiency were further tested for IgG-tTG. Serum samples positive for IgA or IgG-tTG were further tested for IgA antiendomysial antibodies (IgA-EMAs) using an indirect immunofluorescence method. Small-intestinal biopsy was offered to all subjects with tTG antibody positivity. RESULTS: Of the 20,190 subjects, 489 were antibody positive (IgA-tTG only in 270, both IgA-tTG and IgA-EMA in 215, and IgG-tTG in 4). Selective IgA deficiency was detected in 108 patients, and 4 of them were positive for IgG-tTG. An intestinal biopsy was conducted in 215 subjects (IgA-tTG positive in 110, IgA-tTG and IgA-EMA positive in 104, and IgG-tTG positive in 1). The biopsy findings of 95 children were consistent with CD. Thus, the estimated biopsy-proven prevalence was 1: 212 children. The positive predictive value (PPV) for IgA-tTG plus EMA was 75.9%. PPV was 44.3% when only IgA-tTG was used. CONCLUSIONS: We estimate that the prevalence of CD is at least 0.47% in healthy Turkish school children. Screening for IgA-tTG plus EMA provided better results for diagnosis when compared with testing for IgA-tTG alone.