HIV-DNA undetectability during chronic HIV infection: frequency and predictive factors

Background HIV-DNA is a marker of HIV reservoirs. Objectives of the study were to determine prevalence of HIV-DNA < 100 copies/106 PBMCs in blood and to identify factors associated with this in a cohort of HIV-1-infected subjects treated with ART and with undetectable viral load (VL). Methods This was a cross-sectional study on chronic HIV-1-infected people living with HIV (PLWH) followed up at the Department of Infectious Diseases of San Raffaele Scientific Institute on current ART without change for 12 months, with available pre-ART HIV-RNA and with undetectable VL for ≥12 months. HIV-DNA was amplified and quantified by real-time PCR (ABI Prism 7900); limit of detectability was 100 copies/106 PBMCs. Logistic regression was used to identify predictive factors for HIV-DNA < 100 copies/106 PBMCs. Results Four hundred and sixty-eight PLWH were considered in the analyses, 119 (25%) with HIV-DNA < 100 copies/106 PBMCs. At multivariate analysis, we found that PLWH with lower zenith HIV-RNA, higher nadir CD4 and a shorter time between HIV diagnosis and ART start were more likely to have HIV-DNA < 100 copies/106 PBMCs, after adjustment for age, gender, calendar year of ART start, type of current ART regimen, percentage time spent with undetectable VL since ART start, current CD4 and CD4/CD8 ratio. Conclusions In our chronic PLWH on virological suppression for 4 years, the prevalence of HIV-DNA < 100  copies/106 PBMCs was found to be 25%. Lower zenith HIV-RNA, shorter time between HIV diagnosis and starting ART and higher CD4 nadir were independently associated with low HIV-DNA.