Autoimmune hepatitis type 2 and hepatitis C virus infection: study of HLA antigens

Background/Aims: Markers for hepatitis C virus are often detectable in patients suffering chronic hepatitis with liver-kidney microsomal type 1 antibodies. Several authors have suggested that two subsets of those patients can be defined: a) hepatitis C virus negative and b) hepatitis C virus positive. The aim of this work was to further analyze the possible genetic association, HLA class I and II, in these two groups of patients. Methods: HLA was analyzed in 49 patients. Class I was studied using a standard lymphocytotoxicity test and in class II a reverse hybridization-based test for DRB1 typing and PCR-SSO for DQB1 typing were used. Sixty healthy Spanish subject and 39 chronic hepatitis C subjects without anti-LKM1 antibodies were used as control groups for the “a” and “b” subsets, respectively. Results: No significant association was found with class I specificities in either group. DQB1 typing showed a very significant increase of DQ2 in the “a” group (93.3% vs. 48%; RR=15; pc=0.0025), and DRB1 typing from the “b” group reversed a high association with DR7 (82.3% vs. 43.6%; RR=6; pc=0.0086). Conclusions: Our stuides revealed a strong association with DQ2 for the “a” group and for the first time an extremely high association with DR7 antigen for the “b” subset. Hence it is possible to establish a different genetic profile in these two patient groups.