Objective: The aim of the study was to compare accepted surrogate markers of HIV disease progression with markers of lymphocyte apoptosis in their ability to predict short-term disease progression.

Methods: In all, 40 HIV-positive patients were studied prospectively and observed during follow-up for HIV-related adverse clinical events. Ex vivo apoptosis was measured with the markers CD95 expression, annexin V binding, and Apostain dye uptake by flow cytometry at baseline. Established markers of disease progression (CD4 count, HIV-RNA level, and CD8/38 count), CD8, B-cell, and natural killer (NK) cell counts were determined by standard procedures at baseline and after 6 months.

Results: In HIV-infected patients, CD95 expression and annexin V binding showed significantly elevated apoptosis in peripheral blood lymphocytes and all lymphocyte subsets at baseline compared with HIV-negative, healthy controls. Apostain failed to differentiate between HIV-infected patients and healthy controls. HIV-related complications could be predicted by CD4 and CD8/38 counts, but not HIV viral load as assessed by relative operating characteristic (ROC) analysis (CD4, p=. 003; CD8/38, p=. 031). A similar or even better diagnostic accuracy was found for CD95 expression in total lymphocytes (p<. 001), the CD4+(p=. 003) and CD8+(p=. 005) T-cell subsets and for annexin V binding in CD4+ T cells (p=. 005). When patients with CD4 counts< 200 cells/[mu] l were analyzed separately, only annexin V binding in CD4+ T cells, but none of the other prognostic markers could predict complications (p=. 001).

Conclusion: Determination of annexin V binding on CD4+ T cells may be a useful tool to monitor HIV-infected patients with low (< 200 cells/[mu] l) CD4 counts, as it can reliably assess the risk for imminent complications in such patients.