Role of HLA-DQ typing and antitissue transglutaminase antibody titres in diagnosing coeliac disease among Sudanese children with type 1 diabetes mellitus

Abstract

Objective The aim of the study was to determine the prevalence of coeliac disease (CD) and to recognise Human leukocyte antigen (HLA)-associated hereditary susceptibility to Sudanese CD patients with type 1 diabetes mellitus (DM1). Design Antitissue transglutaminase IgA (anti-TG IgA) was measured in the serum of 373 children affected with DM1 aged 1-19-year old and in 100 serum samples from non-diabetic control children. Histological examination was performed in 19 children seropositive for anti-TG IgA (17 DMI and 2 controls). Additionally, PCR-based analysis of Major histocompatibility complex, class II, DQ beta 1 (HLA-DQB1) genotyping was implemented in three study population groups as follows: group 1 (n=25) (+ve DM1 and +ve CD), group 2 (n=63) (-ve DM1 and +ve CD) and control group 3 (n=2) (+ve CD). Results Twenty-six Sudanese children with DM1 out of 373 (6.97%) were seropositive for anti-TG IgA. Duodenal biopsy revealed Marsh 2 and 3 in 13 out of 17 (76.47%) seropositive anti-TG IgA patients with DM1. Significant association (p<0.05) was detected between the level of anti-TG IgA autoantibodies (IU/mL) and Marsh stage. HLA DQ2 and DQ8 were found in 88% (22/25) and 8% (2/25) of examined patients with CD with DM1, respectively. Conclusions Anti-TG IgA titre of greater than 10 times upper limit of normal (≥10× ULN) can be useful for detecting CD in children with type 1 diabetes without duodenal biopsy. HLA testing in children with DM1 appears to provide little added benefit given the high prevalence (96%) of HLA DQ2/DQ8 in children with DM1.