Priapism during filtration leukapheresis.

Priapism has been observed during two out of 3,680 filtration leukapheresis procedures in male donors and has been reported during hemodialysis. Both procedures are associated with enhanced granulocyte adhesion and aggregation presumably due to C5a. During both procedures, heparin is administered and this drug has been shown to cause heparin-dependent anti-platelet antibodies. It is suggested that complement mediated venous leukostasis or immune-induced platelet aggregates might impair the normal blood flow from the penis and result in a state of priapism.