Background/aims: We aimed to identify the genetic factors associated with increased tendency toward autoimmune hepatitis, a chronic and progressive inflammatory condition.
Methods: A total of 32 children diagnosed with autoimmune hepatitis were included in the present study, and 160 healthy adult blood donors served as controls. In both groups, HLA phenotypes were examined (HLA-A, B, C, DR, DQ) and compared. In addition, the association between the type of autoimmune hepatitis and HLA status was explored.
Results: Compared to controls, patients with autoimmune hepatitis had increased frequencies of the following class 1 HLA antigens: A24.9 (28% vs. 9%, p=0.007), A26 (25% vs. 3%, p<0.001), A32 (34% vs. 4%, p<0.001), B38 (9% vs. 0.6%, p=0.015), and B51 (16% vs. 0%, p<0.001). Among class II HLA antigens, DRB1*04 (22% vs. 0%, p<0.001), DRB1*07 (9% vs. 0%, p=0.004), DRB1*11 (12% vs. 0%, p=0.001), DRB1*15 (25% vs. 0%, p<0.001), DRB1*14 (31% vs. 0%, p<0.001), and DR11.5 (9% vs. 0%, p=0.004) were more frequent in patients compared to controls. Type 1 autoimmune hepatitis was associated with high frequencies of A24.9, A26, A32, and DRB1*15, whereas type 2 autoimmune hepatitis was associated with high frequencies of A26, B51, B38, and DRB1*11. On the other hand, frequencies of A32 and DRB1*04 were high among patients with unclassified autoimmune hepatitis.
Conclusions: There seem to be associations between certain HLA antigens and susceptibility to autoimmune hepatitis, but variations among different geographical locations suggest a role for environmental factors.