Prospective evaluation of accuracy of HIV viral load monitoring using the Aptima HIV Quant Dx assay with fingerstick and venous dried blood spots prepared under field conditions in Kenya

Abstract

Quantification of HIV-1 RNA is essential for clinical management of HIV patients. The limited throughput and significant hands-on time required by most HIV Viral load (VL) tests makes it challenging for laboratories with high test volume, to turn around patient results quickly. The Hologic Aptima HIV-1 Quant Dx Assay (Aptima), has the potential to alleviate this burden as it is high throughput and fully automated. This assay is validated for both plasma and dried blood spots (DBS), which are commonly used in resource limited settings. The objective of this study was to compare the performance of Aptima to Abbott RealTime HIV-1 Assay (Abbott RT), which was used as reference. This was a cross-sectional prospective study where HIV VL in finger stick (FS) DBS, venous blood (VB) DBS and plasma, collected from 258 consenting adults visiting 5 medical facilities in Kenya, Africa were tested in Aptima. The results were compared to plasma VL in Abbott RT at the medical decision point (MDP) of 1000 copies/mL and across Aptima assay range. The total agreement at MDP between plasma HIV VL in Abbott RT and plasma, FS and VB DBS tested in Aptima were 97.7%, 92.2% and 95.3% respectively with kappa statistic of 0.95, 0.84 and 0.90. The positive and negative agreement for all 3 sample types were >92%. Regression analysis between VL in Abbott RT plasma and various sample types tested in Aptima had a Pearson’s correlation coefficient ≥0.91 with systematic bias of < 0.20 log copies/mL on Bland-Altman analysis. The high level of agreement in Aptima HIV VL results for all 3 sample types with Abbott RT plasma VL along with the high throughput, complete automation, and ease of use of the Panther platform makes Aptima a good option for HIV VL monitoring for busy laboratories with high volume of testing.

Comparison of the performance of Aptima HIV-1 Quant Dx Assay with Abbott RealTime HIV Assay for viral load monitoring using plasma and Dried Blood Spots collected in Kenya

“…Although only venous DBS were tested in this study, we previously compared the recovery of HIV-1 from venous DBS, fingerstick DBS, and plasma with the Aptima test [ 23 ] showing good agreement between plasma, venous DBS, and fingerstick DBS. One limitation of the current study is that no replicate testing or retesting of invalid specimens was performed due to volume limitation for these clinical samples.…”

“…In a previous study [ 23 ], we investigated the performance of the Aptima HIV Quant Dx assay using fingerstick and venous dried blood spots prepared under field conditions. In that study, we did not compare HIV-1 VL in Aptima with those in other assays using DBS.…”

“…Instead it was compared to the Aptima plasma HIV-1 VL. In fact, whereas multiple studies compared VL results of paired DBS and plasma samples at the medical decision point of 1000 copies/ mL by testing both sample types in Aptima [23][24][25][26], there is no published information comparing the performance of DBS specimens tested in Aptima and other assays at the medical decision point (MDP) of 1000 copies/mL.…”

Use of laboratory-developed assays in global HIV-1 treatment-monitoring and research

“…Most viral load testing in LMICs is done in centralized public laboratories using expensive, government owned platforms requiring high maintenance costs, highly skilled labour, and long test turnaround times. Widely used commercial VL assays include the Real-time HIV-1 (Abbott Molecular, USA); the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test, v2.0 (Roche Molecular Diagnostics, Basel, Switzerland) 15 ; and the Hologic Aptima® HIV-1 Quant Dx Assay on the Panther platform 15 , 16 . The high cost of the assays (up to $100 per test) coupled with the logistics of cold-chain transport of reagents and samples to centralized testing laboratories continues to limit the accessibility of VL testing in resource-constrained settings (RCS) 9 .…”

Oral manifestations of HIV-infection in patients based on CD4+ T-lymphocyte counts

“…Выяснено, что провоцирующими этиологическими факторами развития некротизирующих заболеваний пародонта являются курение, наличие грибов видов Candida, неправильное питание и отсутствие гигиены полости рта [66]. Вышеперечисленными факторами ряд авторов объяснил развитие ЯНГ у пациентов без тяжелого иммунодефицита [68][69][70].…”