Factor VIII coagulant activity and factor VIII-related antigen released from isolated perfused human spleens.

Eight human spleens were perfused for up to 65 h at normothermia and the coagulant Factor VIII activity measured in the perfusate. In addition, in three experiments Factor VIII-related antigen was determined in the perfusate. Although the spleens were pathologically enlarged and the normal structure involved by different diseases, all spleens released Factor VIII coagulant activity and Factor VIII-related antigen. On average the total amount of Factor VIII coagulant activity released was equivalent to that of 3.5 l of human plasma.