Older age at infection and nulliparity are associated with long-term non-progression in female sex workers infected with non-subtype B HIV-1

Studies have reported on HIV-infected, antiretroviral therapy (ART)-naïve individuals who show minimal disease progression despite prolonged infection. The characteristics of these long-term non-progressors (LTNPs) are not well-characterized in populations predominantly infected with non-subtype B HIV-1. Female sex workers in Mombasa, Kenya who acquired HIV-1 were studied to ascertain immunologic disease progression. Long-term non-progression was defined as an ART-naïve duration of infection ≥7 years and a majority of CD4+ cell counts ≥600 cells/µl with a non-declining CD4+ trend. Correlates of long-term non-progression were determined using multivariable logistic regression. Between February 1993 and March 2014, 332 women acquired HIV-1. Of these, 77 (23%) had ≥7 years of follow-up and 13 (17%) were categorized as LTNPs. Factors associated with long-term non-progression included age >30 years at infection (aOR = 9.41, 95% CI: 1.48–59.86, P = 0.005) and nulliparity (aOR = 20.19, 95% CI: 1.36–299.90, P = 0.03). Each log10 copies/ml increase in viral load (VL) set point was associated with a lower likelihood of being a LTNP (aOR = 0.31, 95% CI: 0.12–0.79, P = 0.01). These findings suggest that age and parity may influence the likelihood of long-term non-progression through mechanisms that are not mediated by the effects of these variables on VL. Future studies should seek to determine whether the associations presented are reproducible.