This project is concerned with the continuous flow manipulation of cellular and humoral blood components. Methods of improving granulocyte collection from normal donors using shunts and centrifugation will be investigated. A prospectively randomized controlled study will evaluate prophylactic granulocytes for patients over 50 years of age receiving initial remission induction for acute leukemia. A prospectively randomized study will compare the effect of the decision to protect patients undergoing allogeneic marrow transplantation with laminar air flow isolation or prophylactic granulocyte transfusions. The effects of plasma exchange and continuous flow plasma immunoperfusion on immune disease and malignancy will be studied in dogs and man.