The effect of leukocyte transfusions on experimental bacteremia in the dog.

S EVERE GRANULOCYTOPENIA induced by drugs, irradiation or primary disorders of the hemopoietic system frequently results in uncontrollable sepsis and death. Attempts at treating or preventing sepsis in such patients have generally involved the use of antimicrobial drugs and, more recently, the exploration of sophisticated methods of patient isolation and environmental bacterial control.1’2 Despite these efforts, infection remains the most common cause of death in the patient with marrow failure.3’4 Granulocyte replacement therapy offers a rational approach to this problem but has been limited by the difficulties of granulocyte procurement and storage and by the short life span of these cells, particularly in the infected individual. In addition, the potential hazards of homologous leukocyte infusions include production of graft-versus-host disease.5 Despite these limitations, initial efforts at infusing granulocytes into septic leukopenic patients have suggested that temporary control of bacteremia can be achieved.6In view of the complexities of the clinical setting and the technical problems of designing controlled studies of the application of leukocyte infusions in preventing or controlling sepsis, an in vivo animal model system for evaluating the potential usefulness of leukocyte transfusions would be helpful. The present studies were carried out with the following aims: (1) to develop a standard system for producing gram-negative septicemia in the leukopenic dog, (2) to evaluate the effect of leukocyte transfusions on the course of septicemia using fresh or irradiated leukocytes obtained from normal dogs and (3) to apply the NCI-IBM continuous flow centrifuge as a method of leukocyte procurement from normal donors.