HIV low-level persistent viremia under new antiretroviral regimens: what we have learned up to this point?

Methods A cohort, retrospective study was conducted in Adult Clinic I of the National Institute for Infectious Diseases “Prof. Dr. Matei Bals”, Bucharest, over a 6 year-period (01.2008-12.2013). The main inclusion criteria were: HIV-positive patients stable on ART (>6 months) at their first regimen, good adherence and absence of other medication susceptible for drug-drug interactions with ART. We recorded the demographical data (age/gender), the HIV transmission route, CDC stage, the baseline immune-virological status (CD4 count, HIV-VL and genotypic mutations) and ART regimen. There were also registered subsequently CD4 count and HIV-VL (biannually taken). We then analyzed the management of the patients found with LLV: maintaining the current ART regimen and close monitoring, ART intensification or ART switch. LLV was defined as VL >50 and <1000 copies/mL in at least 2 determinations over a 24 week-period, after at least 24 weeks of stable ART. Results Of 61 patients screened, 35 met the inclusion criteria. The median age was 38 years, (IQR, 32-51) and 71.4% (n = 25) were male. According to 1993 CDC classification, 42.8% (n = 15) were A2 and 22.8% (n = 8) were C3. Sixty percent (n = 21) were heterosexually infected. The median baseline CD4 count was 292 cells/cmm (IQR, 179-376), and median VL was 5.1 log10 copies/mL (IQR, 4.4-5.4). Two patients had detectable baseline mutations. All ART regimens contained 2 NRTI plus one as following: boosted-lopinavir (11 patients), efavirenz (10 patients), boosted-darunavir (6 patients), boostedatazanavir (5 patients) and raltegravir (3 patients). Of 11 patients (31.4%) who had detectable VL at 6 months, 5 met the LLV definition criteria. Their median VL was 267 copies/mL and the median CD4 count was 551/cmm. None of them had had baseline mutations. They didn’t have changes in the current ART regimen, except one patient in whom we increased darunavir dose to 1200 mg/ day. At 12 months their median CD4 count raised to 743/cmm and the median VL declined to 150 copies/mL.