Granulocyte transfusions in neutropenic patients

Patients with severe neutropenia are at increased risk for systemic infection with bacteria or fungi. This risk is in proportion to both the degree and duration of the neutropenic process. Although granulocyte transfusion as a means of augmenting host defenses would appear to be a logical therapeutic intervention in clinical contexts involving severe and prolonged neutropenia, several features of granulocyte physiology and collection complicate such considerations. These include the large numbers of granulocytes normally produced by healthy hosts, the short survival of the granulocyte in the circulation after transfusion, the relatively small number of granulocytes which can be collected using currently available pheresis techniques, problems associated with alloimmunization, and the possibility of transferring disease (CMV, toxoplasmosis, hepatitis) by means of these transfusions. In the mid-1970s, well-designed clinical studies strongly suggested that patients with documented Gram-negative sepsis or tissue infection that failed to respond to appropriate antibiotics were significantly benefited by granulocyte transfusions. With recent advances in potent, broad-spectrum antibiotic availability, some have questioned whether these observations remain valid. Several studies regarding the prophylactic use of granulocyte transfusions in patients undergoing allogeneic bone marrow transplantation and/or induction therapy for leukemia have failed to reveal therapeutic benefits and suggested the possibility of significant side effects. These studies are reviewed.