Sex-Related Differences in Inflammatory and Immune Activation Markers Before and After Combined Antiretroviral Therapy Initiation.

Abstract

Women progress to death at the same rate as men despite lower plasma HIV RNA (viral load). We investigated sex-specific differences in immune activation and inflammation as a potential explanation. Inflammatory and immune activation markers [interferon γ, tumor necrosis factor (TNF) α, IL-6, IL-18, IFN-γ-induced protein 10, C-reactive protein (CRP), lipopolysaccharide, and sCD14] were measured at weeks 0, 24, and 48 after combination antiretroviral therapy (cART) in a random subcohort (n = 215) who achieved virologic suppression in ACTG A5175 (Prospective Evaluation of Antiretrovirals in Resource-Limited Settings). Association between sex and changes in markers post-cART was examined using random effects models. Average marker differences and 95% confidence intervals were estimated using multivariable models. At baseline, women had lower median log10 viral load (4.93 vs 5.18 copies per milliliter, P = 0.01), CRP (2.32 vs 4.62 mg/L, P = 0.01), detectable lipopolysaccharide (39% vs 55%, P = 0.04), and sCD14 (1.9 vs 2.3 µg/mL, P = 0.06) vs men. By week 48, women had higher interferon γ (22.4 vs 14.9 pg/mL, P = 0.05), TNF-α (11.5 vs 9.5 pg/mL, P = 0.02), and CD4 (373 vs 323 cells per cubic millimeter, P = 0.02). In multivariate analysis, women had greater increases in CD4 and TNF-α but less of a decrease in CRP and sCD14 compared with men. With cART-induced viral suppression, women have less reduction in key markers of inflammation and immune activation compared with men. Future studies should investigate the impact of these sex-specific differences on morbidity and mortality.