Immunogenetics of autoimmune diseases in Asian Indians.

The HLA class II molecules play a critical role in the processing and presentation of specific peptides derived from autoantigens of pancreatic beta cells or gluten for T cell scrutiny in IDDM and CD. In the present study, extended DR3-positive haplotypes associated with autoimmunity in northern Indian patients have been reported. The haplotype A26-B8-DR3 was the most common autoimmunity-favoring haplotype encountered among these patients. This association is, indeed, unique to Indian autoimmune patients, as it replaces the otherwise most commonly associated Caucasian haplotype A1-B8-DR3 (AH8.1) in this population. Further, CD patients revealed 100% association with DQB1*0201 along with DQA*0501 (97%) either in cis or trans configuration.