MHC class II sequences of susceptibility and protection in Mexicans with autoimmune hepatitis

Background/Aims: Autoimmune hepatitis has a genetic background associated with different HLA DRB1 alleles depending on the ethnic group. The aim of this study was to analyse the immunogenetics of type I autoimmune hepatitis in Mexicans. Methods: Thirty Mexican Mestizo patients and 175 healthy controls were HLA typed as follows: class I antigens were determined by microlymphocytotoxicity and class II typing was done on DNA samples using PCR-SSO and PCR-SSP for DRB1, DQA1 and DQB1 loci. Results: A significant association of autoimmune hepatitis with DRB1*0404 was found, (c 2 Y‰19.95, pc‰0.002, RR‰7.71), suggesting the presence of a susceptibility gene located at the DRB1 locus. Resistance was at least partially due to a DQB1 gene, since a significant decrease in DQB1*0301 was also detected (c 2 Y‰8.21, pc‰0.04). Analysis of subgroups