Unaltered lymphocyte subsets in hepatitis C virus-seropositive blood donors.

Lymphocyte subsets were evaluated by dual-color flow cytometry in whole blood specimens from 35 blood donors who were seropositive on enzyme-linked immunosorbent assay (ELISA) for hepatitis C virus (HCV) and whose sera reacted in a four-antigen recombinant immunoblot assay (RIBA) (referred to as the HCV+R group), 15 donors who were seropositive on ELISA for HCV with indeterminate or negative RIBA results (the HCV+I/N group), and 25 HCV-seronegative controls (HCV-group). The cell subsets assessed included natural killer cells, B cells, T cells, CD4 and CD8 subsets of T cells, and T-cell subsets defined by the coexpression of markers that appear (HLA-DR, CD25, CD38) or disappear (CD45RA) after activation. A one-way analysis of variance revealed no significant differences among the three study groups. These findings show that, unlike cytomegalovirus- and human immunodeficiency virus-positive individuals, HCV-positive individuals do not exhibit lymphocyte alterations indicative of the immune activation caused by chronic viral infection.