Quantitation of HIV-1 RNA in dried blood spots by the real-time NucliSENS EasyQ HIV-1 assay in Senegal

Abstract

Measurement of viral load in plasma remains the best marker for the follow-up of antiretroviral therapy. However, its use is limited in developing countries due to the lack of adequate facilities and equipment, and cryopreservation of plasma during storage and transportation. Practical and reliable methods adapted to field conditions for the collection, transportation and accurate measurement of HIV-1 viral load are needed for the optimum use of antiretroviral therapy in resource-limited countries. This study evaluated the use of dried blood spots (DBS) for the real-time quantitation of HIV-1 RNA levels with the NucliSENS EasyQ ® HIV-1 assay (bioMérieux, Lyon, France) under field conditions in Senegal (Africa). Dried blood spots and plasma from 41 patients living in suburban Dakar were used for determination of HIV-1 RNA concentrations and stability at 37 °C. Analysis was performed at the Dakar University Hospital laboratory. Extraction was done with the bioMérieux NucliSENS ® miniMAG™, and real-time detection was done with the bioMérieux NucliSENS ® EasyQ system. HIV-1 RNA concentrations in plasma were compared with concentrations in dried blood spots after 8 and 15 days at 37 °C. The study showed a strong concordance in RNA levels between plasma and dried blood spots, which appear to be very stable over time with no apparent degradation observed after 2 weeks at 37 °C (mean difference 0.065 log IU/ml). These results suggest that the use of dried blood spots in combination with the NucliSENS EasyQ HIV-1 assay is well adapted for HIV-1 RNA level monitoring in centralized laboratories in developing countries.