Prospective study of hepatitis after factor VIII concentrate exposed to hot vapour.

A factor VIII concentrate prepared from large plasma pools and then exposed to hot vapour to inactivate blood-borne viruses was evaluated in 28 factor-VIII deficient patients (14 vaccinated against the hepatitis B virus, HBV) who had not been treated with any blood product and hence were highly susceptible to the development of post-transfusion hepatitis. Tests for aminotransferases and HBV markers were made every 2 weeks in the first 4 months and at 5, 6 and 12 months. Twenty-four patients were considered not to have developed hepatitis, either because they had no elevations of aminotransferases or did not become seropositive for HBV markers. The four remaining unvaccinated patients (three treated with the same batch and the fourth with a different one) developed HBV infection 8-24 weeks after the first concentrate infusion. Hence, this method of viral inactivation did not afford complete protection from hepatitis B.