Prevalence and characteristics of celiac disease in South African patients with type 1 diabetes mellitus: Results from the Durban Diabetes and Celiac Disease Study

Background and Aim: The aim of this study was to assess the prevalence and characteristics of celiac disease (CD) in all patients with type 1 diabetes mellitus attending a tertiary adult diabetes clinic in Durban, South Africa. Methods: This was a cross-sectional observational study that screened 202 patients; of these, 56.4% were African (Black), 31.7% Asian Indian, 4.5% White, and 7.4% mixed race. Demographic data, symptoms, and anthropometry were documented. Blood tests included anti-tissue transglutaminase antibody (tTG), anti-endomysial antibody (EMA), and anti-gliadin antibody (AGA). Endoscopy and duodenal biopsy were performed in patients with celiac antibodies. Diagnosis of CD was based on the modified Marsh classification. Results: Mean age and mean duration of diabetes were 26.4 ± 11.4 and 10.7 ± 9.1 years, respectively. Celiac antibodies were found in 65 (32.2%) patients: EMA 7.4%, tTG immunoglobulin A (IgA) 8.4%, tTG immunoglobulin G 1.9%, AGA IgA 18.3%, and AGA immunoglobulin G 21.8%. Histological evidence of CD was found in 5.9% (n = 12/202): 2.5% were classed as definite CD (Marsh 3) and 3.4% as potential CD (Marsh 1). None of the patients with CD were symptomatic. The sensitivity of AGA IgA, EMA, and tTG IgA antibodies for detecting histologically proven CD was 66.7%, 50.0%, and 41.7%, respectively. Conclusion: The prevalence of CD was similar to reports from western countries. No ethnic specific differences were noted. CD was silent in all patients in this study. The sensitivity of EMA and tTG antibodies was poor and merits further evaluation as screening tools for CD in South African patients with type 1 diabetes mellitus.