CD95 expression and apoptosis during pediatric HIV infection: Early upregulation of CD95 expression

Pediatric HIV infection is characterized by a progressive decline in CD4 T lymphocytes and faster disease progression than is typically seen in adults. Apoptosis, possibly mediated through the CD95 antigen, has been proposed as a mechanism for cell loss which eventually leads to immune dysfunction. In this study of peripheral blood lymphocytes from HIV-infected children, classified according to CDC immunologic categories, we found that the percentage of CD4 and CD8 T cells expressing CD95 and the percentage of lymphocytes undergoing apoptosis were increased in children with HIV infection and were greater in children from immunologic Category III as compared to those in Category I. Most striking was our observation that an increased percentage of CD95-positive cells appeared as early as 3 months of age, at a time when these children did not have elevated levels of apoptosis. These data demonstrate early upregulation of CD95 expression in HIV-infected infants, an abberation which may have profound implications for the pathogenesis of perinatally acquired IIIV disease. (C) 1998 Academic Press.