APOPTOSIS-RELATED MORTALITY IN-VITRO OF MONONUCLEAR-CELLS FROM PATIENTS WITH HIV-INFECTION CORRELATES WITH DISEASE SEVERITY AND PROGRESSION

Peripheral blood mononuclear cells (PBMC) from 103 HIV-infected patien ts were tested for their mortality rate (MR) when incubated in vitro f or 3 days in a culture medium. MR was related to apoptosis as shown by DNA analysis and morphological evaluation of ethidium bromide-stained PBMC by flow cytometry. MR was significantly higher in patients in CD C stage IV as compared to patients in stage II or III (p = 0.017). MR was also higher in patients with low CD4 cells/mm(3) (p = 0.014 for pa tients with <400 cells; p = 0.001 for patients with <200 CD4 cells/mm( 3)) and with low percentage of CD4 cells (p = 0.001 for patients with <10% of CD4 cells). A significant negative correlation was observed be tween MR and both absolute numbers or percentages of CD4 cells (p < 0. 001). The addition of interleukin-2 (IL-2) and fibroblast-conditioned medium (FCM) to the cultures significantly reduced MR. However, the ab ility of both IL-2 and FCM to preserve viability was significantly ass ociated with p24 negativity. Clinical and immunological follow-up was available for 60 patients for a mean period of 26 months. MR at the be ginning of the study was significantly higher in the group of patients who clinically progressed (according to the CDC classification) or di ed during the follow-up (p < 0.0001). Our data suggest that MR correla tes with both disease severity and progression and that MR is directly related to the depletion of CD4 cells in cultures. We also propose th at CD4 depletion contributes to increased in vitro cell death observed in HIV infection through impaired cytokine production.