Follow up survey after infusion of a heat-treated factor VIII concentrate to untreated patients (virgin cases)

Hepatitis infection in haemophiliacs has been a major problem in their replacement therapy, and factor VIII concentrates manufactured from pooled plasma were realized to be the cause of transmission of AIDS virus. However, several investigators have shown that some of these viruses are inactivated by chemical or physical treatment on factor VIII concentrates. After infusion of a heat-treated factor VIII concentrate (heat-treated at 65°C for 96 hours), a follow up study was carried out in 11 patients who had no infusion of blood nor blood preparations beforehand. During the observation period, there was detected no sign of hepatitis in all patients, and no positive seroconversion to AIDS virus was proved. These results were in a good agreement with the experimental data previously reported from in vitro as well as in vivo experiments where chimpanzees were employed for virus infection test. For the evaluation of the safety for viral infection of clotting factor concentrates in clinical use, these survey results in untreated patients are of a great importance.