Clinical studies with treated clotting factor concentrates.

Area of Science:

• Hematology
• Virology
• Infectious Diseases

Background:

• Congenital coagulatory defects require treatment with clotting factor concentrates.
• Viral hepatitis transmission is a significant risk associated with blood product transfusions.
• Previous methods for viral inactivation of clotting factors had varying efficacy.

Purpose of the Study:

• To evaluate the safety of different clotting factor concentrate treatment methods.
• To assess the efficacy of viral inactivation in preventing hepatitis B and non-A, non-B hepatitis.
• To determine the impact of treatments on the transmission of Human T-lymphotropic virus type III/Lymphadenopathy-associated virus (HTLV-III/LAV).

Main Methods:

• Safety studies were conducted on 45 previously untreated patients with congenital coagulatory defects.
• Patients received clotting factor concentrates treated with different methods: dry heating, dry heating with chloroform, hot-steam treatment, and chromatography.
• Viral markers (hepatitis B, non-A, non-B hepatitis, HTLV-III/LAV antibody) were monitored post-infusion.

Main Results:

• Non-A, non-B hepatitis occurred in patients receiving dry heated F VIII (with or without chloroform).
• No non-A, non-B hepatitis was observed in patients treated with hot-steam F VIII or chromatography-treated F IX.
• Hepatitis B developed in three unvaccinated patients receiving the same lot of hot-steam treated F VIII.
• No patient developed HTLV-III/LAV antibody.

Conclusions:

• Dry heating of clotting factor concentrates is ineffective in preventing hepatitis transmission.
• Hot-steam treatment and chromatography show greater efficacy in preventing hepatitis transmission but are not entirely safe.
• All tested methods, except hot steam for hepatitis B, appear to prevent HTLV-III/LAV transmission.