Early changes in T-cell activation predict antiretroviral success in salvage therapy of HIV infection

OBJECTIVE:: Because effective antiretroviral therapy (ART) reduces immune activation, we hypothesize that early changes in immune activation are associated with subsequent virologic response to therapy. DESIGN:: Observational cohort study. SETTING:: Institutional HIV clinic. SUBJECTS:: Thirty-four adult HIV patients with virologic failure on their current antiretroviral regimen. INTERVENTION:: Change to salvage regimen selected by patient's physician. MAIN OUTCOME MEASURES:: Measures of immune activation at baseline and at 2, 4, 8, and 24 weeks after enrollment. Data were analyzed by proportional hazards (PH) models. RESULTS:: PH models showed that reductions between baseline and week 2 in expression of CD38 (P = 0.02) or CD95 (P = 0.02) on CD4 T cells were associated with increased likelihood of achieving virologic suppression. Kaplan-Meier analysis demonstrated that patients who had reductions within the first 2 weeks of therapy in CD4 T-cell expression of CD38 (P = 0.003) or CD95 (P = 0.08) were more likely to achieve viral suppression than those who did not. CONCLUSIONS:: Reduced CD4 T-cell expression of CD38 and CD95 occurring within 2 weeks of salvage therapy is associated with subsequent viral suppression. Monitoring CD38 and CD95 may allow earlier assessment of the response to ART.