Plasma HIV-2 RNA According to CD4 Count Strata among HIV-2-Infected Adults in the IeDEA West Africa Collaboration

Abstract

BackgroundPlasma HIV-1 RNA monitoring is one of the standard tests for the management of HIV-1 infection. While HIV-1 RNA can be quantified using several commercial tests, no test has been commercialized for HIV-2 RNA quantification. We studied the relationship between plasma HIV-2 viral load (VL) and CD4 count in West African patients who were either receiving antiretroviral therapy (ART) or treatment-naïve.MethodA cross sectional survey was conducted among HIV-2-infected individuals followed in three countries in West Africa from March to December 2012. All HIV-2 infected-patients who attended one of the participating clinics were proposed a plasma HIV-2 viral load measurement. HIV-2 RNA was quantified using the new ultrasensitive in-house real-time PCR assay with a detection threshold of 10 copies/ mL (cps/mL).ResultsA total of 351 HIV-2-infected individuals participated in this study, of whom 131 (37.3%) were treatment naïve and 220 (62.7%) had initiated ART. Among treatment-naïve patients, 60 (46.5%) had undetectable plasma HIV-2 viral load (<10 cps/mL), it was detectable between 10-100 cps/mL in 35.8%, between 100-1000 cps/mL in 11.7% and >1000 cps/mL in 6.0% of the patients. Most of the treatment-naïve patients (70.2%) had CD4-T cell count ≥500 cells/mm3 and 43 (46.7%) of these patients had a detectable VL (≥10 cps/mL). Among the 220 patients receiving ART, the median CD4-T cell count rose from 231 to 393 cells/mm3 (IQR [259-561]) after a median follow-up duration of 38 months and 145 (66.0%) patients had CD4-T cell count ≤ 500 cells/mm3 with a median viral load of 10 cps/mL (IQR [10-33]). Seventy five (34.0%) patients had CD4-T cell count ≥ 500 cells/mm3, among them 14 (18.7%) had a VL between 10-100 cps/mL and 2 (2.6%) had VL >100 cps/mL.ConclusionThis study suggests that the combination of CD4-T cell count and ultrasensitive HIV-2 viral load quantification with a threshold of 10 cps/mL, could improve ART initiation among treatment naïve HIV-2-infected patients and the monitoring of ART response among patients receiving treatment.

New Highly Sensitive Real-Time PCR Assay for HIV-2 Group A and Group B DNA Quantification

“…of infants born to seropositive HIV-2 mothers, and for studying the HIV-2 reservoir. Plasma viremia is undetectable in many HIV-2-infected patients in the absence of antiretroviral therapy, particularly in those with high CD4 T cell counts (11). HIV-2 DNA may be the only detectable marker in these patients.…”

“…In the French National HIV-2 Cohort, 71% of antiretroviral-naive patients had plasma viral loads below 100 copies/ml (10). Data from a West Africa cohort showed that 46.5% of antiretroviral-naive patients had undetectable HIV-2 RNA (Ͻ10 copies/ml), and 35.8% had low HIV-2 RNA loads of 10 to 100 copies/ml (11). In this context, HIV-2 DNA may be the only detectable viral marker for patients with undetectable HIV-2 RNA.…”

Low Level of HIV-2 Replication in Patients on Long-Term Antiretroviral Therapy in Togo

“…It has been shown in West Africa cohort study that 46.5% of HIV-2 infected patients were well controlling infection [21]. This seems due to a better immune response including better protection and less immunopathology [22].…”

Assessment of the Cavidi ExaVir Load Assay for Monitoring Plasma Viral Load in HIV-2-Infected Patients

“…As a reference comparative assay, we used an in-house qPCR based assay that is in current use at reference institutions in Portugal and other European countries (4,5,10,(38)(39)(40)(41)54). The associations between viral load and CD4 ϩ T cell counts or antiretroviral therapy status were similar for measurements obtained with ExaVir Load and qPCR.…”

“…In HIV type 2 (HIV-2)-infected individuals, this evaluation is hindered by the inexistence of a "goldstandard" method for the quantification of HIV-2 viral load in the plasma. Unlike with HIV-1, for which there are commercial tests to quantify plasma viral load, specific quantification of plasma viral load in HIV-2-infected patients is only obtained through in-house assays developed for research use (4)(5)(6)(7)(8)(9)(10). This circumstance likely results from the low prevalence of HIV-2 infection worldwide.…”