HLA DRB1 Alleles Discriminate the Manifestation of Autoimmune Hepatitis as Type 1 or Type 2 in North Indian Population

Abstract

Autoimmune hepatitis is a polygenic disorder of unknown etiology, where genetic factors affect the occurrence and clinical phenotype of the disease. It has been reported as a rare disease entity in the Indian subcontinent. This study was undertaken to investigate the association of HLA alleles with autoimmune hepatitis type 1 and type 2 in north Indian population and to analyze if distinct human leukocyte antigen (HLA) alleles help in characterization of the subtypes of autoimmune hepatitis. Sixty-eight patients with autoimmune hepatitis and 128 healthy controls were recruited in the study. Out of 68 patients, 55 were diagnosed with autoimmune hepatitis type 1 and 13 with autoimmune hepatitis type 2. The patients and the controls were typed for HLA class II alleles by PCR-SSP method. HLA DRB1*04 and DRB1*08 were found to be significantly associated with autoimmune hepatitis type 1 in north Indian population. It was also observed that DRB1*04, DRB1*13 were significantly associated with pediatric autoimmune hepatitis type 1 and DRB1*08 was significantly associated with adult autoimmune hepatitis type 1. DRB1*14 was significantly associated with autoimmune hepatitis type 2. The study indicates that autoimmune hepatitis in north Indian population is associated with HLA alleles that may help to discriminate the subtypes as autoimmune hepatitis type 1 and type 2. The study also highlights the ethnic variations in the Indian subcontinent in context to the genetic association of HLA with autoimmune diseases.