DNA STAINING CHANGES ASSOCIATED WITH APOPTOSIS AND NECROSIS IN BLOOD-LYMPHOCYTES OF INDIVIDUALS WITH HIV-INFECTION

We used flow cytometry to quantitate cells that die by apoptosis or ne crosis. The method uses low concentrations of two DNA binding dyes tha t allow one to establish selective regions for live, apoptotic, and ne crotic cells in a rat thymocytes model. Quantitative analysis of blood lymphocyte death in individuals with HIV infection by this technique shows the presence of nonviable cells that exhibit a spectrum of chang es in staining by DNA binding dyes. These changes range from typical f eatures of cells undergoing programmed cell death or apoptosis to chan ges observed in cells that die by accidental death or necrosis. The pr oportion of cells exhibiting these lethal changes increases significan tly in patients who progress to AIDS, but, although cells with stainin g features associated with apoptosis and necrosis were both found to b e increased in in vitro-activated cells from AIDS patients, spontaneou s in vivo activation preferentially leads to apoptotic changes without a significant increase of cells exhibiting the staining changes assoc iated with necrosis. (C) 1995 Wiley-Liss, Inc.