Low-level viremia is associated with non-B subtypes in patients infected with HIV with virological success following HAART introduction.

This prospective study aimed to determine factors associated with detection of very low-level viremia in patients infected with HIV-1 with virological success following HAART introduction. Fifty-seven patients, mostly (n = 51, 89%) treated with a protease inhibitor-based regimen, were included and followed for 2 years. Viral loads were monitored by Abbott m2000 RealTime HIV-1. Patients were classified as (i) HIV-RNA-negative if viral loads remained strictly undetectable (0 copies/ml), or (ii) HIV-RNA-positive if at least one HIV-1 RNA could be detected in 1-49 copies/ml during follow-up. At month 24, 44 patients (77%) were in the HIV-RNA-positive group, whereas 13 (23%) remained without very low-level viremia. Univariate analysis, Kaplan-Meier curves and the Cox proportional hazard model revealed that B subtype was the only predictor of belonging to the HIV-RNA-negative group (HR 3.98; 95% CI 1.08-14.7). This association needs to be confirmed. Further study of the reservoir and the mechanisms of viral latency according to HIV-subtype will also be necessary to develop new therapeutic strategies and eradicate HIV infection.