Pasteurization of C1 inactivator in the presence of citrate salts

Conditions have been determined under which the C1 inactivator (C1-INA) can be pasteurized to reduce the risk of transfusion hepatitis associated with its use for replacement therapy in patients with genetic or acquired deficiencies. Recovery of 90% of the biological and immunological activity of a C1-INA concentrate was achieved following heat treatment for 10 h at 60 degrees C in the presence of 3 M potassium citrate. Crossed immunoelectrophoresis in heparinized agarose was used to demonstrate the ability of the pasteurized C1-INA to bind heparin and to form a precipitation pattern with antibody which was almost indistinguishable from that of an unheated control. High pressure liquid chromatography and enhancement of the fluorescence of 1,8-anilinonaphthalene sulfonate were used to show that other proteins present in the concentrate were also stabilized.