CD95 EXPRESSION AND APOPTOSIS DURING PEDIATRIC HIV-INFECTION - EARLY UP-REGULATION OF CD95 EXPRESSION

Pediatric HIV infection is characterized by a progressive decline in C D4 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 catego ries, we found that the percentage of CD4 and CD8 T cells expressing C D95 and the percentage of lymphocytes undergoing apoptosis were increa sed in children with HIV infection and were greater in children from i mmunologic Category III as compared to those in Category I. Most strik ing was our observation that an increased percentage of CD95-positive cells appeared as early as 3 months of age, at a time when these child ren did not have elevated levels of apoptosis. These data demonstrate early upregulation of CD95 expression in HIV-infected infants, an abbe ration which may have profound implications for the pathogenesis of pe rinatally acquired IIIV disease. (C) 1998 Academic Press.