Journal of clinical microbiology 2017 07 12() pii 10.1128/JCM.00755-17
HIV-2 infection is characterized by a very low replication in most cases and low progression. That necessitates a different approach to patient monitoring than that for HIV-1 infection. Here, a new, highly specific, and sensitive method for HIV-2 DNA quantification has been developed. The new test is based on quantitative real-time PCR, targeting the LTR and Gag regions and using an internal control. Analytical performance was determined in three laboratories and clinical performance on blood samples from 63 patients infected with HIV-2 group A (n=35) or group B (n=28). The specificity was 100%. The 95% limit of detection was three copies/PCR and the limit of quantification was six copies/PCR. The within-run coefficients of variation were between 1.03% at 3.78 log10 copies/PCR and 27.02% at 0.78 log10 copies/PCR. The between-run coefficient of variation was 5.10%. Both manual and automated nucleic acid extraction methods were validated. HIV-2 DNA load was detectable in blood cells of all 63 patients. When HIV-2 DNA was quantifiable, median loads were significantly higher in antiretroviral-treated than in naïve patients, and were similar for groups A and B. HIV-2 DNA load was correlated with HIV-2 RNA load (r = 0.68, IC95% = [0.4-0.8], p<0.0001). Our data show that this new assay is highly sensitive and quantified the two main HIV-2 groups, making it useful for diagnosis of HIV-2 infection and pathogenesis studies on HIV-2 reservoirs.