Clinical outcome after 4 years follow-up of HIV-seropositive subjects with incomplete virologic or immunologic response to HAART.

The duration of the clinical, virologic, and immunologic response to HAART, is not well defined. In this observational multi-center study 2,143 patients were enrolled classified according to virologic suppression (<500 cp/ml) and immune recovery (>100 CD4+ cells/mul from baseline) at month 12 of HAART as complete responders, virologic only responders, immunologic only responders and non-responders. Kaplan Meyer curves, multivariate and politomous regression analysis were used. Complete responders patients were 781 (36.4%), immunologic only responders 441 (20.6%), virologic only responders 336 (15.7%), and non-responders 585 (27.3%). Using multivariate analysis, being antiretroviral-naive increased the probability of having both a virologic only or a complete response and reduced the probability of an immunologic only response (P < 0.001 for all tests). Older age was associated directly with a virologic only response and inversely associated with an immunologic only response (P = 0.027 and P = 0.035, respectively). Using politomous analysis, patients baseline HIV-RNA level more than 5 log cp/ml had a 1.9-fold higher probability of an immunologic response than of a complete response (P = 0.001). After 4 years, the clinical progression rate was six times greater in non-responders, 1.9 times greater in virologic only responders, and 2.3 times greater in immunologic only responders than for responders. However, patients with virologic only response or with immunologic only response had a significantly reduced risk for clinical progression than non-responders (P < 0.001). After 4 years of HAART, the risk of clinical progression in patients with immunologic only or virologic only response is low but still higher than in complete responder patients.