Clinical, biologic, and behavioral predictors of early immunologic and virologic response in HIV-infected patients initiating protease inhibitors

Predictors of virologic (plasma HIV RNA viral load [VL] < 500 copies/ml) an d immunologic (rise in CD4(+) cell count > 50 cells/mm(3)) response after 4 months of therapy (M4) were studied in 750 HIV-1-infected patients prospec tively enrolled at the initiation of a protease inhibitor (Pl)-containing r egimen. A virologic response was observed in 80% of patients, and an immuno logic response was observed in 64%. Sixty-two percent of patients self-repo rted full adherence to therapy at I month of therapy (M1) and M4. In multiv ariate analysis, a virologic response was more frequent in fully adherent p atients (odds ratio [OR] = 2.0, p = .001). An immunologic response was asso ciated with age < 36 years (OR = 1.4; P = .03), baseline VL (OR = 1.5 per I log(10), copies/ml higher p < .01), decrease in VL at MI (OR 1.5 per I log (10) copies/ml decrease, p < .01). baseline total lymphocyte count (OR 1.7 per 50% lower: p < .001), and baseline CD4(+) cell percentage greater than or equal to 20% (OR = 1.9; p < .001) but not with adherence to therapy. Ful l adherence seems to be a major predictor of a virologic response to PI-con taining triple therapy. An immunologic response may be possible despite inc omplete adherence, at least early in therapy.