Whatman FTA(R) cards versus plasma specimens for the quantitation of HIV-1 RNA using two Real-Time PCR assays

Abstract

BackgroundSeveral studies have been conducted to compare the use DBS as alternative to plasma specimens, but mainly using Whatman 903(R) cards as filter paper. The aim of this study was to evaluate Whatman FTA(R) cards (FTA cards) specimens for HIV-1 viral load testing by comparing it to plasma specimens, using 2 real-Time PCR assays.\n\nMethodologyA cross-sectional study was conducted between April 2017 and September 2017, in HIV-1 patients admitted at Yalgado Ouedraogo teaching hospital. Paired FTA cards and plasma specimens were collected and analyzed using Abbott RealTime HIV-1 assay (Abbott) and COBAS(R) AmpliPrep/COBAS(R) TaqMan v2.0 (Roche), following manufacturers protocol.\n\nResultsA total of 107 patients were included. No Statistical differences (p-value > 0.05) were observed between the mean viral loads obtained from FTA cards and plasma specimens with Roche and Abbott assays. Twenty-nine samples with Roche and 15 samples with Abbott assay showed discrepant results. At viral loads of [≤]1000 copies/mL, the sensitivity and specificity of FTA cards were 78.6%, and 100% with Roche, and 92.3% and 95.9% with Abbott. Strong correlation was found between FTA cards and plasma specimens with both assays. With Roche, Bland-Altman analysis showed bias of -0.3 and 95% limits of agreement of -2.6 to 1.8 log10, with 97/99 cases (97.9%) within agreement limits. With Abbott, Bland-Altman analysis showed bias of -0.1 and 95% limits of agreement of -2.3 to 2.1 log10, with 96/99 cases (96.9%) within agreement limits.\n\nConclusionOur study demonstrated the feasibility of using FTA cards filter paper for HIV-1 viral load testing. However, further studies are required for FTA cards filter paper validation in HIV-1 treatment monitoring.