Rate of and predicting factors for virologic failure in HIV-infected patients with persistent low-level viremia under antiretroviral therapy.

To determine the rate of and predicting factors for virologic failure among HIV-infected patients with persistent low-level viremia (PLV) under antiretroviral therapy (ART), a retrospective cohort study was conducted among HIV-infected patients who experienced PLV under ART. Persistent low-level viremia was defined as HIV RNA level at 50 to 1000 copies/mL for at least 2 consecutive visits. Of 68 patients, mean ± standard deviation age was 35.2 ± 9.0 years and 64.7% were males. Median (interquartile range [IQR]) CD4 count was 94 (26-264) cells/mm(3) and baseline HIV RNA was 112 000 (1 090-461 500) copies/mL. During the median (IQR) follow-up period of 5.7 (3.4-10.3) years of ART, the rate of virologic failure was 38.2%. In multivariate analyses, only maximum amplitude of HIV RNA >400 copies/mL during PLV (hazard ratio = 5.668; 95% confidence interval, 1.888-17.014; P = .002) significantly predicted virologic failure. Patients with PLV >400 copies/mL are more likely to develop virologic failure and should be closely monitored. Interventional studies to prevent virologic failure in these patients are needed.