Virologic, immunologic, and clinical response to highly active antiretroviral therapy: the gender issue revisited

Background: Highly active antiretroviral therapy (HAART) has dramatically improved the prognosis for patients with HIV. There is ongoing debate over a potential gender effect on patient outcome after HAART. Methods: Individuals were from the EuroSIDA cohort, naive to protease inhibitors and nonnucleoside reverse transcriptase inhibitors, and had at least one viral load and CD4 measurement prior to starting HAART. Endpoints were virologic (time to <500 copies/mL, time to rebound [first of two consecutive viral loads >500 copies/mL]), immunologic (time to a 100/mm cell rise in CD4 count) and clinical (time to new AIDS and death). Hazard ratios (HR), derived using Cox regression models, compared female to male rates of achieving endpoints. Results: Of 2547 patients, 20% (511) were female. Significantly more females than males were nonwhite (24% vs. 10%, p <.001). Males were older (median age 39 vs. 35 years, p <.0001), had lower CD4 counts (211 vs. 240/mm, p =.03), higher viral loads (4.6 vs. 4.4 log copies/mL, p <.0001), were more likely to have a history of AIDS (26% vs. 18%, p <.001) and were more likely to be treatment-naive (34% vs. 29%, p =.03). Adjusted HR for association between gender (comparing females with males) and the outcomes studied were as follows: for reaching <500 copies/mL 0.91 (0.81-1.03, p =.17), rebound 1.17 (0.95-1.44, p =.15), for 100 cell CD4 count rise 1.02 (0.88-1.14, p =.99), for progression to new AIDS 1.12 (0.73-1.71, p =.59) and for time to death 1.15 (0.69-1.92, p =.57). Conclusions: We found no significant evidence of a gender difference in virologic, immunologic, or clinical outcomes after starting HAART.