Incidence of viral hepatitis after administration of factor IX concentrates

A high frequency of viral hepatitis has been reported after treatment with the human factor IX concentrate 'Konyne'. Clinical trials with 'Konyne' and a similar factor IX concentrate, called 'Preconativ', was started in Sweden 1969. During the first 2 years, 26 patients were treated with either one or both preparations. Nine patients developed viral hepatitis within 6 months after treatment. 'Preconativ' alone was introduced on the Swedish market in 1971. During the period 1971-1974, another 26 hemophiliacs were treated but only two cases of hepatitis have occurred. Selection of donors and screening for hepatitis B surface antigen in donor blood used for the manufacturing of 'Preconativ', might be contributing factors to this low hepatitis incidence.