Stability of HIV-1 RNA in blood during specimen handling and storage prior to amplification by NASBA-QT

Abstract The influence of different storage temperatures and anticoagulation conditions on the HIV-1 RNA load as measured by NASBA-QT was examined. Blood specimens from 14 HIV-1 infected individuals were processed within 2 h after collection. The HIV-1 RNA load remained stable for at least 6 months when samples were frozen directly at −70°C in lysis buffer. This lysis buffer fully inactivated the virus. When whole EDTA blood was stored, the HIV-1 RNA load was stable for 72 h at 25°C, but it declined within 24 h at 4°C. The HIV-1 RNA load in whole heparinized blood declined significantly after 24 h at both 4 and 25°C. It was slightly lower (average of 0.18 log ml −1 ) than in whole EDTA blood. At 4°C, the HIV-RNA load in serum and EDTA-plasma stored with lysis buffer did not decline up to 14 days. At +30°C, however, the load declined significantly after 2 days. Of clinical significance, the mean load in EDTA plasma was 0.5 log ml −1 higher than in serum. This difference was patient dependent (range 0.1–0.7 log ml −1 ). We thus recommend, for quantifying HIV-1 RNA by NASBA, to use preferably EDTA blood which is kept at room temperature until plasma separation. When using heparinized blood, the plasma should be stored frozen within 8 h.