Use of HLA typing in diagnosing celiac disease in patients with type 1 diabetes.

OBJECTIVE This study examines the use of HLA typing for the diagnosis of celiac disease in a group of Australians with type 1 diabetes. RESEARCH DESIGN AND METHODS Subjects included 131 sequential patients with type 1 diabetes (mean age 17 years [range 10-37]), 77 patients with biopsy-proven celiac disease (mean age 52 years [range 12-84]), and 162 healthy control subjects (mean age 17 years [range 2 months to 56 years]). Subjects were prospectively screened for celiac disease using endomysial antibodies (EMAs), tissue transglutaminase antibodies (TTGAs), and celiac disease-specific HLA typing. RESULTS Celiac disease was diagnosed in 11 subjects after an intestinal biopsy (prevalence 8.4%). There was 95% agreement between TTGA and EMA for positive results and 100% for negative results. There was no significant difference for HLA DQ2 and DR4 among patients with type 1 diabetes with or without celiac disease. CONCLUSIONS The prevalence of celiac disease among patients with type 1 diabetes is higher than previously estimated in Australia. TTGA is a valuable diagnostic tool that can be used for screening celiac disease in patients with type 1 diabetes. HLA typing should not be used in the diagnosis of celiac disease in patients with type 1 diabetes because of the similarities of HLA types between patients with type 1 diabetes and those with celiac disease.