Elevated HLA class I antigen expression on peripheral blood mononuclear cells of HBsAg carriers with coexistent human immunodeficiency virus infection.

The density of HLA Class I antigen on peripheral blood mononuclear cells was evaluated by flow cytometry in the following groups of patients: 41 HBsAg carriers; 12 individuals with chronic non-A, non-B hepatitis, and 4 with acute hepatitis B. Fourteen of the carriers were positive for antibody to human immunodeficiency virus, and all were negative for antibody to delta agent. Elevated levels of Class I antigen were observed in only 19% of patients with chronic hepatitis B virus infection alone. In contrast, 86% of HBsAg carriers with coexistent human immunodeficiency virus infection demonstrated increased expression. These data suggest that HBsAg carriers are capable of sustaining a systemic interferon response to another chronic viral infection and further supports the hypothesis that a defective interferon response exists in chronic hepatitis B virus infection.