Plasma collected from heparinized blood is not suitable for HCV-RNA detection by conventional RT-PCR assay.

Detection of hepatitis C virus-RNA (HCV-RNA) in serum or in plasma is considered a reliable marker for ongoing HCV infection. HCV-RNA was measured routinely in plasma collected from heparinized blood of patients with chronic hepatitis C and varying results were found. In this study, HCV-RNA was detected in peripheral blood mononuclear cells (PBMCs) and in serum of 16 out of 17 anti-HCV positive patients with chronic hepatitis C. In contrast, HCV-RNA was found in plasma collected from heparinized blood of only one of these seventeen patients. The addition of heparin to known HCV-RNA containing solutions before reverse-transcription and separately before PCR, demonstrated the inhibitory effect of heparin on the reverse transcription and amplification reaction. Furthermore, evidence is provided that plasma for PCR should be collected preferably into EDTA vacutainers. It is concluded, therefore, that plasma collected from heparinized blood is not suitable for HCV-RNA determination by RT-PCR. In addition, PBMCs might play an important role in the pathobiology of hepatitis C virus, since HCV-RNA was easily detected in PBMC of patients with chronic hepatitis C.