Analysis of apoptosis and a Th1/Th2 phenotype in HIV-infected patients

Lymphocytes from HIV patients, unlike those from normal HIV-negative subjects, underwent apoptosis upon in vitro culture. We found that the percentage of lymphocytes undergoing apoptosis was significantly higher (P = 0.005) in patients with low CD4 cell counts (< 200 CD4 cells/microliter) (60%) than in patients at earlier stage (> 500 CD4 cells/microliter) (35%). Serum IgE levels increased in two of six patients at last stage and in two of five patients at earlier stage. Spontaneous production of both IL-2 and IL-10, by peripheral blood mononuclear cells (PBMC) after 48 h in culture, was greater in HIV-infected subjects and increased with disease progression. IFN-gamma production was greater in HIV-infected subjects but there was no evident change with disease progression. IL-4 production was barely detectable or not detected in both HIV-infected and HIV-negative individuals. These results indicate that spontaneous apoptosis is associated with advanced disease. However, there was no evidence of in vivo switch from the Th1 to Th2 phenotype in HIV-infected patients.