Level of HIV DNA in peripheral blood mononuclear cells correlates with efficacy of antiretroviral therapy

A novel colorimetric assay was developed and validated for accurate quantitation of HIV DNA in PBMCs. We tested 318 sequential samples from 56 subjects, 53 of whom were undergoing dual or triple therapy. Patients were considered responders when viremia levels were below 5,000 HIV RNA copies/ml: 3,492 and 1,242 were mean RNA copy number of responders, while 55,916 and 34,880 were of nonresponders. The mean DNA copy number for untreated and responder subjects were similar (72 and 75, respectively), while it was 4.54-fold higher for nonresponders (339). Moreover, it was higher for dual-therapy nonresponders than for triple therapy nonresponders, 390 and 288, respectively. This report (J Clin Microb, in press) provides strong evidence that HIV DNA levels in PBMCs correlate with therapeutic efficacy and suggests that DNA quantitation is a useful tool to monitor the decay of the HIV reservoir towards disease remission, especially when viremia is undetectable. Since both unintegrated and integrated HIV DNA forms were measured, the 2LTR circular unintegrated form was amplified in 91 samples from 15 patients. 2LTR DNA correlates with viral replication, but was also present in samples from patients with persistently undetectable viremia suggesting residual or cryptic HIV replication.