Gender differences in HIV drug resistance mutations and virological outcome.

Background: Previous studies have shown that female gender has higher odds of developing HIV drug resistance mutations. We aimed to evaluate the gender differences in HIV drug resistance mutation patterns and outcomes in a cohort of an HIV-infected population who underwent genotype resistance testing (GRT).

Methods: We conducted a retrospective study from January 2004 to April 2007 of patients >12 years of age who underwent GRT in the HIV Outpatient Program Clinic (HOP) at the Medical Center of Louisiana at New Orleans.

Results: Among 391 patients included in the analysis, 130 were females and 261 were males. There were no major statistically significant differences in the baseline demographic, clinical, or genotypic characteristics between males and females before GRT except for race, presence of coexisting hepatitis B and C infection, prior diagnosis of tuberculosis, presence of thymidine analogue mutations (TAMs), and protease inhibitor (PI) mutations L90M and I84V (p < 0.05). Females showed a 1.6 fold probability of carrying nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.02-2.6), whereas males showed a 2-fold probability of carrying PI mutations (OR 2, 95% CI 1.12-3.8). Sixty-seven percent of males achieved virological suppression compared with 57% of females at 1 year (±6 months). Independent of history of optimal treatment and race, females showed 2-fold odds of having virological failure compared with males at 1 year (±6 months) after GRT (OR 2.0, 95% CI 1.04-3.8).

Conclusions: Females did worse than males in regard to viral load suppression at the end of 1 year if they had documented HIV drug resistance at baseline. Further longitudinal studies are needed to confirm our findings.