Preanalytical stability of HIV-1 and HCV RNA: impact of storage and plasma separation from cells on blood donation testing by NAT.

BACKGROUND The aim of this study was to evaluate the optimal preanalytical conditions prior to nucleic acid amplification technology (NAT) for human immunodeficiency virus-1 (HIV-1) or Hepatitis C virus (HCV) RNA in pools of 96 plasma specimens with regard to storage temperature, time and plasma separation in a blood donation environment. STUDY DESIGN AND METHODS Changes in viral nucleic acid concentration of HIV-1 and HCV were observed for 5 days according to the Paul-Ehrlich-Institute's (PEI) guidelines that demand 95%-detection limit of at least 10 000 IU mL(-1) for HIV-1 RNA and 5000 IU mL(-1) for HCV RNA within a single donor blood specimen. Ninety-five per cent detection limits of HIV-1 RNA over 3 days after storage at either 5 or 21 °C were evaluated by using standardised HIV-1 RNA-positive plasma. RESULTS HCV RNA in whole blood samples proved to be more stable than HIV-1 RNA. Whole blood storage at 21 °C was shown to decrease the detectability of HIV-1 RNA even after only 18 h. Plasma samples once used for NAT at time 18 h did not alter viral stability up to 48 h after donation. Ninety-five per cent detection limits of HIV-1 RNA were securely below 10 000 IU mL(-1) for 24 h after whole blood storage at 5 °C. CONCLUSIONS These results may lead to a discussion around the most suitable preanalytical conditions in blood donation environments. Contrary to the current PEI guidelines that allow storage of whole blood specimens up to 18 h at 21 °C, these results suggest that immediate storage in a 5 °C container after blood donation is more suitable and would permit storage of whole blood up to 24 h prior to the separation of plasma from cells.