Analysis of human plasma products: polymerase chain reaction does not discriminate between live and inactivated viruses

BACKGROUND: The viral safety of human plasma products is based on the careful selection of donors and donations and the removal and inactivation of human pathogenic viruses that could potentially contaminate human plasma. For the analysis of the final products for potential virus contamination, the use of polymerase chain reaction (PCR) has been proposed. To test whether this method can discriminate between infectious and inactivated viruses, the following studies were performed. STUDY DESIGN AND METHODS: Infectious and virus-inactivated preparations were titrated with specific PCR, using viruses such as hepatitis B virus (HBV), hepatitis C virus, bovine viral diarrhea virus, and poliovirus. The inactivation method employed was pasteurization (10 hours, 60 degrees C) or solvent/detergent (SD) treatment; in the case of HBV, there was consecutive treatment by both methods. RESULTS: Pasteurization of HBV and hepatitis C virus as well as SD treatment of HBV or pasteurization of HBV followed by SD treatment did not affect the detectability of these viruses by PCR, whereas an infectivity study in chimpanzees demonstrated that infectious hepatitis C virus was inactivated by pasteurization. Pasteurization also had no effect on the PCR titers of stabilized bovine viral diarrhea virus or poliovirus preparations, but it destroyed the infectivity of these viruses completely after only 4 hours' heat treatment. CONCLUSION: Pasteurization or SD treatment destroys the infectivity of the viruses tested, but neither significantly affects their detectability by specific PCR. Therefore PCR is not a suitable measure for testing the viral safety of finished plasma products that have been subjected to virus inactivation.