Gender differences in clinical progression of HIV-1-infected individuals during long-term highly active antiretroviral therapy

Objective: To assess gender differences in the long-term clinical, virological and immunological outcomes during highly active antiretroviral therapy (HAART). Methods: This longitudinal observational multicentre study followed 2460 HIV-infected patients who had begun a protease inhibitor-based regimen for a median period of 43 months. Outcome measures were virological suppression (<500 copies/ml), confirmed virological rebound after suppression, and death or new AIDS-defining illness (ADI). Results: At baseline, 690 female patients (28.0%) had significantly lower age, higher prevalence of heterosexual contact and lower prevalence of intravenous drug use as risk factors for HIV infection compared with males. Furthermore, females had a lower number of AIDS-defining illnesses, higher CD4 cell counts and lower viral loads. No gender differences were reported in terms of proportion of patients achieving viral suppression or exhibiting rebound after achieving viral suppression. Female patients experienced reduced clinical progression during follow-up compared with males (P=0.008) by Kaplan-Meier analysis; however this difference was not significant in an adjusted analysis. In a multivariate model, the interaction between gender and risk factor for HIV or viral load showed that female drug users and female patients with a baseline HIV RNA viral load of 10⁴-10⁵ copies/ml had a favourable clinical outcome compared with males (P=0.035 and P=0.015, respectively). Conclusion: No differences were found between genders in terms of virological and immunological outcomes during long-term HAART. Nevertheless, a lower risk of clinical progression was reported among female patients with intermediate baseline viral load than in males.