Impact of Early Antiretroviral Therapy on Detection of Cell-Associated HIV-1 Nucleic Acid in Blood by the Roche Cobas TaqMan Test

Abstract

The Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test, v2.0 (the CAP/CTM assay), was used to quantify cell-associated HIV-1 (CAH) nucleic acid in peripheral blood mononuclear cells (PBMC) from well-characterized clinical specimens from HIV-1-infected individuals on antiretroviral therapy (ART). Chronically infected individuals on ART with no detectable plasma HIV-1 RNA demonstrated average CAH burdens of 3.2 HIV-1 log10 copies/million cells. Assay sensitivity and specificity were 98.9% and 100%, respectively, with the positive and negative predictive values being 100% and 98.6%, respectively. The CAH burden was also measured at weeks 0, 1, 2, 8, and 60 in 37 participants (RV254/SEARCH010, Bangkok, Thailand) stratified by Fiebig stage (Fiebig stage I [FI] to FVI) at ART initiation. Prior to ART initiation, the average CAH burden was 1.4, 4.1, and 3.6 log10 copies/million PBMCs for individuals who initiated ART at FI, FII, and FIII to FVI, respectively. Initiation of ART resulted in a rapid decline of CAH in all individuals, with the greatest decrease being observed in individuals who initiated ART at FI to FIII. By week 60, 100% (FI), 71.8% (FII/FIII), and 20.5% (FIV to FVI) of samples from individuals initiating treatment were at or near the limit of quantitation. Residual CAH was detectable at 60 weeks in most individuals who initiated ART at later stages (FIV to FVI) and averaged 1.9 ± 0.7 log10 copies/million PBMCs. The modified Roche CAP/CTM assay provides a convenient, standardized approach to measure residual HIV in blood and may be useful for monitoring patients under therapy or those participating in HIV remission studies.

Decreased Seroreactivity in Individuals Initiating Antiretroviral Therapy during Acute HIV Infection

“…Only 27/57 (47%) of RNA-positive individuals who were infected while on PrEP were found to be reactive by the Bio-Rad GS HIV Combo Ag/Ab EIA, and none were HIV-1 positive by either the HIV-1 WB or the Geenius assay (53). Alternative approaches, such as testing for cell-associated HIV total nucleic acid (RNA and DNA), may be required to rule out HIV-1 infections in individuals with inconclusive HIV diagnostic test results and may be helpful to confirm infections in such cases (6,54). decision, unless so designated by other documentation.…”

Performance evaluation of a laboratory developed PCR test for quantitation of HIV-2 viral RNA

“…Alternative approaches, such as testing of whole blood or PBMCs for HIV-2 total nucleic acid (TNA: RNA and DNA) may be more appropriate for those applications [26,28,41]. Our studies with HIV-1 infections demonstrated that the HIV-1 TNA is readily detected in ART treated HIV-1 infected individuals even in the absence of detectable plasma viral load [43]. Indeed, several studies of HIV-2 infected individuals have shown that viral nucleic acid can be readily detected by TNA testing of whole blood and PBMCs even when plasma viral load is very low or undetectable [25,26,28].…”

False reactive HIV-1 diagnostic test results in an individual from Kenya on multiple testing platforms-A case report

“…Qualitative HIV RNA testing was performed on plasma (Aptima HIV-1 RNA Qualitative Assay, Hologic Inc., San Diego, CA). Since the participant was on ART for almost 8 weeks prior to sample collection, it was likely that plasma HIV RNA tests would be negative, hence quantitative cell-associated HIV nucleic acid (both RNA and DNA) was measured using multiple aliquots of whole blood lysates and cell pellets with a modified version of the COBAS AmpliPrep/COBAS TaqMan HIV-1 Test v2.0 (Roche Diagnostics, Indianapolis, IN, USA) [ 8 ]. All HIV-1 nucleic acid tests were negative.…”