FPA content - a criterion of quality for plasma as factor VIII source

The appearance of fibrinopeptide A (FPA) in plasma indicates that factor VIII has been at least partially activated; consequently, we asked the following questions: (1) Is the FPA content of single donor plasma influenced by the method of blood collection? (2) Does a high FPA content of the starting fresh frozen plasma impair the quality of factor VIII preparations? Using a modified procedure adapted to the assay of large series of samples, we surveyed the FPA content of normal donor plasma. Our results show that the FPA content of donor plasma depends strongly on the quality of blood collection. Improved mixing of the anticoagulant with the blood led to a drastic reduction of the FPA content of the plasma. Furthermore, two lots of factor VIII concentrates produced from FPA-poor plasma showed significant improvement in stability and solubility.