Study of Spontaneous Apoptosis in HIV + Patients: Correlation with Clinical Progression and T Cell Loss

Abstract

In vitro spontaneous apoptosis (SA) of lymphocytes was studied in HIV infection to evaluate possible clinical and prognostic correlations, in a transsectional study of 101 individuals in different clinical categories and in a prospective longitudinal study of 18 asymptomatic individuals (mean follow-up, 17.2 months). The rate of SA was higher in HIV⁺ patients than in healthy controls (p < 0.001) and was higher in patients with AIDS than in the other HIV⁺ individuals (p < 0.001). It was inversely correlated with the peripheral blood CD4⁺ (R -0.61; p < 0.001) and CD8⁺ (R -0.46; p < 0.001) cell numbers. In a group of long-term survivors (LTS), it was significantly lower than in a control group of asymptomatic HIV⁺ patients with a similar number of circulating CD4⁺ lymphocytes but a shorter follow-up (p < 0.02). In the Five asymptomatic HIV-infected individuals who showed a clinical progression, peaks of SA rates above the normal range before the clinical event were much more frequent than in those who remained asymptomatic (p < 0.0001), even though they were fairly homogeneous as far as CD4⁺ cell count and viral load were concerned. The median levels of SA rates were moreover correlated with the rate of total T cell loss (R -0.46; p 0.053). This study suggests that evaluation of the SA levels may provide a predictive factor for clinical and immunological progression of HIV-related immunodeficiencies and strengthen the hypothesis for the role of this phenomenon in the pathogenesis of this progression.