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

Abstract

267 words 1 8 Abstract 2 3Background: Several studies have been conducted to compare the use DBS as 2 4 alternative to plasma specimens, but mainly using Whatman 903 ® cards as filter 2 5paper. The aim of this study was to evaluate Whatman FTA ® cards (FTA cards) 2 6 specimens for HIV-1 viral load testing by comparing it to plasma specimens, using 2 2 7 real-Time PCR assays. 2 8 Methodology: A cross-sectional study was conducted between April 2017 and 2 9 September 2017, in HIV-1 patients admitted at Yalgado Ouédraogo teaching 3 0 hospital. Paired FTA cards and plasma specimens were collected and analyzed 3 1 using Abbott RealTime HIV-1 assay (Abbott) and COBAS ® AmpliPrep/COBAS ® 3 2TaqMan v2.0 (Roche), following manufacturers' protocol. 3 3 Results: A total of 107 patients were included. No Statistical differences (p-value > 3 4 0.05) were observed between the mean viral loads obtained from FTA cards and 3 5 plasma specimens with Roche and Abbott assays. Twenty-nine samples with Roche 3 6 and 15 samples with Abbott assay showed discrepant results. At viral loads of ≤ 1000 3 7 copies/mL, the sensitivity and specificity of FTA cards were 78.6%, and 100% with 3 8 Roche, and 92.3% and 95.9% with Abbott. Strong correlation was found between 3 9 FTA cards and plasma specimens with both assays. With Roche, Bland-Altman 4 0 analysis showed bias of -0.3 and 95% limits of agreement of -2.6 to 1.8 log10, with 4 1 97/99 cases (97.9%) within agreement limits. With Abbott, Bland-Altman analysis 4 2showed bias of -0.1 and 95% limits of agreement of -2.3 to 2.1 log10, with 96/99 4 3 cases (96.9%) within agreement limits. 4Conclusion: Our study demonstrated the feasibility of using FTA cards filter paper 4 5