Commercial immunodepleted deficient plasmas contain cleaved high molecular weight kininogen (HK)

Comparative analysis of high molecular weight kininogen (HK) in various commercial congenital and immunodepleted deficiency plasmas was performed by immunoblotting of HK. It was found, that some artificially depleted deficiency plasmas contained proteolytically cleaved, kinin-free kininogen. In contrast, in all congenitally deficient plasmas, HK was present in the intact, single chain form. Thus, cleavage of kininogen could have been triggered by or during the immunodepletion procedure. It was seen, that the degree of proteolytic cleavage and degradation of HK in depleted plasmas differed among various manufacturers. E.g. depleted products of one company contained only trace amounts of cleaved HK, in contrast to products of another one, in which HK was completely degraded. The immunoblot analysis of HK reflects the occurrence of proteolytic events during the production of artificially deficient plasmas and can therefore serve as a quality control method.