The prognostic value of discordant immunologic (CD4 cell increase) and virologic (plasma HIV RNA level decrease) responses to antiretroviral treatment is not known.

To study the relation between clinical outcome of HIV-infected patients receiving highly active antiretroviral therapy (HAART) and early immunologic and virologic responses to such therapy.

Prospective cohort study.

68 hospitals in France.

2236 protease inhibitor–naive patients.

Initiation of HAART with one protease inhibitor and two nucleoside analogues between July 1996 and March 1997.

Immunologic and virologic response at 6 months. Multivariate Cox models were used to assess the relation between these responses and progression to a new AIDS-defining event or death.

On the basis of 6-month immunologic and virologic responses, patients were classified into four groups: complete response (47.5%), complete nonresponse (16.2%), immunologic response only (19.0%), and virologic response only (17.3%). After month 6 and within a median of 18 months, 69 patients died and 123 experienced a new AIDS-defining event. After adjustment, complete nonresponders and those with only a virologic response had significantly higher risks for clinical progression at 6 months (relative risk, 3.38 [95% CI, 2.28 to 5.02] and 1.98 [CI, 1.26 to 3.10], respectively) than complete responders. The difference between complete responders and those with only an immunologic response at 6 months was weaker and nonsignificant (relative risk, 1.55 [CI, 0.96 to 2.50]).

Immunologic response after 6 months of HAART indicates a favorable clinical outcome in HIV-infected patients regardless of virologic response. This suggests that both immunologic and virologic markers should be used in clinical practice to evaluate treatment response.