Characterisation and virus safety of alpha 1-proteinase inhibitor

Alpha 1-proteinase inhibitor (alpha 1-PI) concentrate is prepared from Cohn fraction IV-1 by precipitation and ion-exchange chromatography. A pasteurisation step (60 degrees, 10 hours) is introduced in this process with the aim at lowering the risk of transmitting infectious agents. Characterisation studies of alpha 1-PI with electrophoretic, immunologic and chemical methods demonstrated that the final product behaved the same as alpha 1-PI in human plasma. In particular, neo-antigens were not detected and the association rate constant of the final product was shown to be very similar to the constant published in the literature. The inactivation kinetic studies of eight different viruses showed that the heat treatment had a profound effect on their inactivation, the retroviruses such as HIV and Visna becoming undetectable after less than one hour of heat treatment.