HLA alleles appear to influence the exact phenotype-the most interesting apparent association being between HLA-DRB1*0301-DQB1*0201, liver-kidney microsome autoantibodies (anti-CYP1A2), and autoimmune hepatitis.
Because of the persistence of hypertransaminasemia, a percutaneous liver biopsy was performed showing 'low grade chronic active autoimmune hepatitis' (AIH), positive for liver-kidney microsomal autoantibodies and antibodies to the hepatic autoantigen cytochrome P450-1A2.
The five CYP proteins did not react with sera from normal controls nor from patients with chronic hepatitis B. CYP2D6 reacted with sera from 100% (9/9) of AIH type II patients, 79% (19/24) of patients with anti-LKM-1-positive chronic hepatitis C, and 6.5% (2/31) of patients with anti-LKM-1-negative chronic hepatitis C. In contrast, CYP1A2 reacted with serum from one patient with AIH type I, CYP2E1 reacted with sera from two patients with AIH type I, one patient with anti-LKM-1-positive chronic hepatitis C, and two patients with anti-LKM-1-negative chronic hepatitis C, and CYP3A4 reacted with sera from one patient with AIH type II and one patient with anti-LKM-1-positive chronic hepatitis C. CYP2C9 did not react with any of the sera included in this study.