Background: Earlier studies have shown that women have not demonstrated the same benefit from ART as men. Previous data from Columbia Presbyterian Medical Center ID clinic suggest that women are less likely to be on ART when meeting DHHS criteria. It is not clear whether women have a virologic and CD4 response to ART similar to that of men.

Methods: Retrospective chart review of all patients attending CPMC HIV clinic starting a first ART regimen after January 1, 1997. Outcome measures were: having an HIV RNA viral load <400 copies/mL (UVL) within 24 weeks of starting ART;  time from first UVL till virologic failure defined as the first of 2 consecutive viral loads >400 copies/mL; and slope of CD4 change after initiation of ART. Logistic regression was used to evaluate those reaching UVL, and Cox proportional hazards model was used to evaluate time to virologic failure. The slope of CD4 change between groups was compared using a t-test after weighting by the individual slope variance.

Results: 229 patients were included; 35% were female. The reported HIV risk factors for women were heterosexual contact (84%), IDU (13%), and receipt of blood products (3%). The mean baseline CD4 for women prior to starting ART was 152/mm³ compared to 127/mm³ for men (p=NS). The mean baseline log₁₀ viral load was 4.78 for women and 5.03 for men (p=0.006). The mean time from the first clinic visit to starting ART was 355 days for women compared to 184 days for men (p=0.03).  7.5% of women failed to reach UVL compared to 19.5% men (OR 3.0, 95%CI 1.2-7.5). Baseline viral load, CD4, use of NNRTI vs PI and age were not related to reaching UVL. The significant factors for failing to reach UVL in the multivariate model were male gender (OR 4.7, 95%CI 1.6-13.9) and HIV risk factor of IDU (OR 3.8, 95%CI 1.2-11.9). The proportion of women maintaining an UVL 1 year later was .79 (95%CI 0.71-0.87) and 3 years later .70 (95%CI 0.60-0.82) and was similar to men.  The CD4 change for women after HAART was 122/mm³ per year vs 113/mm³ per year for men (p=.13).

Conclusions: Women were started on ART with a similar CD4 as men, but were observed in the clinic for a longer time prior to initiating ART. Once starting ART, women were more likely than men to reach UVL. Men and women maintained a similar, durable virologic and CD4 response to ART.