Clinical and demographic factors associated with low viral load in early untreated HIV infection in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial.

OBJECTIVES

A small subset of HIV-positive adults have low HIV RNA in the absence of therapy, sometimes for years. Clinical factors associated with low HIV RNA in early infection have not been well defined.

METHODS

We assessed factors associated with low plasma HIV RNA level at study entry in the Strategic Timing of AntiRetroviral Treatment (START) trial. All START participants had a baseline HIV RNA assessment within 60 days prior to randomization. The key covariables considered for this analysis were race, and hepatitis B virus (HBV) and hepatitis C virus (HCV) status. We assessed factors associated with HIV RNA ≤ 50 and ≤ 400 HIV-1 RNA copies/mL using logistic regression. Because of the strong association between region of randomization and baseline low HIV RNA, analyses were stratified by region.

RESULTS

We found that, of 4676 eligible participants randomized in START with a baseline HIV RNA assessment, 113 (2.4%) had HIV RNA ≤ 50 copies/mL at baseline, and a further 257 (5.5%) between 51 and 400 copies/mL. We found that HIV exposure routes other than male homosexual contact, higher high-density lipoprotein (HDL) cholesterol levels, higher CD4 cell counts, and higher CD4:CD8 ratio were associated with increased odds of low HIV RNA. HCV antibody positivity was borderline statistically significantly associated with low HIV RNA. Race and HBV surface antigen positivity were not significantly associated with low HIV RNA.

CONCLUSIONS

In a modern cohort of individuals with early untreated HIV infection, we found that HIV exposure routes other than male homosexual contact and higher HDL cholesterol were associated with increased odds of low HIV RNA.