HIV-1 RNA Quantification from Dried Blood Spots and Plasma Using the Siemens VERSANT HIV-1 RNA 1.0 Assay (kPCR)
HIV-1 RNA Quantification from Dried Blood Spots and Plasma Using the Siemens VERSANT® HIV-1 RNA 1.0 Assay (kPCR)
Objective: Dried blood specimens (DBS) use simplifies the sample collection for viral load (VL) testing in some settings. We compared the VL quantification using DBS and the plasma using the Siemens VERSANT® HIV-1 RNA 1.0 (kPCR) Assay. Methods: Paired DBS/plasma samples were prepared from 62 HIV-1 infected patients harboring different HIV-1 subtypes and recombinants and HIV-1 RNA was quantified by kPCR in 62 paired specimens. DBS and plasma VL results were compared. Viraemia values in DBS were corrected for plasma volume differences assuming the hematocrit percentage in each patient. Results: The results showed a good correlation between corrected VL values in DBS and the results obtained in plasma. The intraclass correlation coefficient was 82.3%. The detection rate in DBS was 83.9%, while the sensitivity of the kPCR for DBS was 92.9%. Overall VL in DBS was, on average, 0.8 log (SD = 0.58) lower than in plasma. We observed overestimated VL in DBS specimens with less than 1,000 copies/ml in plasma. Conclusion: DBS can be used for HIV-1 quantification using kPCR and can be useful for the early therapeutic failure detection in treated subjects. However, VL in DBS can be overestimated in specimens with low VL in plasma, maybe due to a higher effect of proviral DNA in quantification. More studies including more HIV-1 variants are needed to define the kPCR performance.