Clinical studies with treated clotting factor concentrates.

We carried out safety studies in 45 previously untreated patients with congenital coagulatory defects, who needed to be treated with clotting factor concentrates. Non-A, non-B hepatitis developed in patients who received dry heated F VIII preparations with or without chloroform, but not in those who were infused with hot-steam treated F VIII or chromatography treated F IX. Hepatitis B developed in 3 unvaccinated patients who received the same lot of hot steam treated F VIII. None of the 45 patients we have investigated developed HTLV-III/LAV antibody. Thus, dry heating of concentrates does not prevent hepatitis transmission. Hot-steam and hydrophobic interaction chromatography seem to be more effective in preventing hepatitis transmission, but not completely safe. All the above procedures except hot steam seem to protect from hepatitis B. They all seem to prevent HTLV-III/LAV transmission.