Leukapheresis and granulocyte transfusion

Abstract

Granulocyte transfusion is becoming widely used in the treatment of infections in granulocytopenic patients. Several techniques are available for granulocyte collection. Some involve centrifugation of the whole blood and one removes granulocytes from whole blood by reversible adhesion to nylon fibers. The risks to the donor from leukapheresis do not appear to be greater than from whole blood donation. Granulocytes collected by centrifuge techniques function normally in vitro and have normal intravascular recovery and disappearance following transfusion. Granulocytes collected by filtration leukapheresis function almost normally in vitro but have a reduced intravascular recovery and abnormal kinetics as they leave the circulation. The role of leukocyte typing and compatibility testing for granulocyte transfusion is controversial. When the recipient has circulating antibody against donor leukocytes, transfused leukocytes do not circulate or migrate to sites of infection but are sequestered in the liver and spleen. Clinical studies have not defined whether patients benefit equally well clinically from transfusion of compatible or incompatible granulocytes. Initial reports of clinical trials of granulocyte transfusion were promising. However, similar patients who did not receive granulocytes were not studied. Most subsequent controlled trials showed a clear benefit from granulocyte transfusion while others did not. Differences in antibiotic therapy, chemotherapy, use of laminar flow rooms, and grouping of patients make it difficult to compare these clinical trials. Some, but not all, infected granulocytopenic patients benefit from transfusion. Granulocyte transfusions improve survival of granulocytopenic patients with gram negative sepsis and prolonged bone marrow aplasia. Studies are now attempting to identify other patients who should receive granulocytes, the optimum dose and schedule of transfusions, the optimum time to begin transfusion, and the value, if any, of prophylactic transfusions.