Hepatitis C Virus RNA Quantitation in Venous and Capillary Small-Volume Whole-Blood Samples

Quantitation of hepatitis C virus (HCV) RNA in plasma and serum samples is a costly procedure in both time and reagents. Additionally, cell-associated viral RNA may not be detected. This study evaluated the accuracy of HCV RNA quantitation in small-volume whole-blood (WB) samples, which would be appropriate for point-of-care diagnostic devices. HCV RNA was extracted from 222 clinical plasma and WB samples of 82 patients with chronic hepatitis C by a specific locked nucleic acid-mediated capture method and quantified by real-time reverse transcription-PCR. The results were compared to the reference plasma viral load determined with the COBAS AmpliPrep/TaqMan (CAP/CTM) HCV test. This assay had an analytical sensitivity of 9 IU per 10-μl sample (95% limit of detection [95% LOD]), a linearity range of 500 to 5 x 10⁶ IU/ml, and was accurate in testing 10 HCV subtypes (900 IU/ml, although the use of WB does not increase the diagnostic sensitivity.