Leukapheresis and granulocyte transfusion

Granulocyte transfusions in the management of invasive fungal infections

Granulocyte transfusions have a long history of being used in patients with neutropenia or neutrophil dysfunction to prevent and treat invasive fungal infections. However, there are limited and conflicting data concerning its clinical effectiveness, considerable variations in current granulocyte transfusion practices, and uncertainties about its benefit as an adjunct to modern antifungal therapy. In this review, we provide an overview on granulocyte transfusions and summarize the evidence on their role in the prevention and treatment of invasive fungal infections.

Effects of granulocyte-colony-stimulating factor on potential normal granulocyte donors

BACKGROUND

The use of granulocyte-colony-stimulating factor (G-CSF) to increase the granulocyte count and the yield from leukapheresis in normal donors is leading to renewed interest in granulocyte transfusion. Therefore, it is important to understand the side effects of G-CSF.

STUDY DESIGN AND METHODS

We studied the effect of G-CSF on peripheral blood counts and recorded the side effects experienced 24 hours after an injection of G-CSF in normal subjects donating peripheral blood progenitor cells for research.

RESULTS

Following administration of G-CSF to 261 donors, the neutrophil count increased to 20.6 to 24.5 x 10(9) per microL depending on the dose of G-CSF. This represented a 6.2 to 7.4-fold increase over the neutrophil count before G-CSF administration. Of all donors, 69 percent experienced one or more side effects. The most common effects were: muscle and bone pain, headache, fatigue, and nausea. There was a relationship between the dose of G-CSF and the likelihood of experiencing a side effect. Most side effects were mild, but about 75 percent of donors took analgesics because of them.

CONCLUSIONS

In a granulocyte donation program involving G-CSF stimulation, about two-thirds of donors would experience one or more side effects, but these would usually be mild and well tolerated.

In vitro study of immunologic changes in long-term cytapheresis donors

Several in vitro measurements of immune function were examined retrospectively in a population of active long-term cytapheresis donors (group I; n = 50) and the results were compared to age- and sex-matched controls (group II; n = 50) who had donated only whole blood. In group I, significantly different mean absolute lymphocyte counts (P = .0025), total T-cells (P = .0026) and T-helper cells (P less than .0001), and helper-to-suppressor ratios (P = .0279) were present. No differences were noted between the two groups for peripheral blood mean B-cell count, T-suppressor numbers, lymphocyte responsiveness to mitogens or alloantigen, and serum immunoglobulin level. The reduced mean absolute lymphocyte count in group I was due to the reduction in T-helper cell numbers and accounted for the imbalance in the helper-to-suppressor ratio. These disturbances are currently unexplained and, while no clinical consequences have so far become evident, there is a need to continuously monitor the immunologic status of cytapheresis donors. It is also important to determine whether reversal of the defects occurs and, if so, over what time interval.

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.

Limited value of in vitro techniques for the detection of leukocyte alloantibodies during granulocyte transfusion therapy

A 23-year-old male patient undergoing first induction chemotherapy for acute myeloid leukaemia received granulocyte transfusions on 10 consecutive days. An average of 2.1 X 10(10) granulocytes was given per square metre body surface area per day. Transfusion reactions and absence of post-transfusion granulocyte increment after the fifth granulocyte transfusion suggested the presence of leukocyte antibodies. However, no antibodies were detectable at this time by the lymphocytotoxicity test, the indirect granulocyte immunofluorescence test, or the platelet suspension immunofluorescence test. In contrast to the clinical observation, the serological detection of leukocyte antibodies was only possible 1 day after the last granulocyte transfusion.

Granulocyte transfusions in acute leukaemia. Regeneration of granulopoiesis as determining factor of survival

40 patients with acute leukaemia and severe granulocytopenia were treated with granulocyte transfusions for bacteriologically documented or clinically suspected septicaemia. The patients received an average of 5 transfusions each with 2.1 X 10(10) granulocytes per m2 body surface area per day. 26 patients showed clinical benefit from transfusion therapy as documented by the course of blood cultures, local lesions and fever. Only patients with regeneration of granulopoiesis had definite benefit from granulocyte transfusions. All other patients died ultimately from septicaemia.

In vitro and in vivo studies on filter collected granulocytes

The in vitro function of granulocytes collected by filtration leukapheresis after premedication of donors with dexamethasone was found to be normal. In vivo studies were performed in a 21-year-old woman who was transplanted with allogeneic bone marrow for severe aplastic anaemia. The patient received granulocyte transfusions for treatment of septicaemia during the transplantation period. On 11 consecutive days an average dose of 7.2 X 10(10) granulocytes/transplantation, the patient died from cardiac failure. Transfused granulocytes were found ante mortem in a pericardial effusion and post mortem in lungs, kidneys, liver and spleen. The data indicate that filter collected granulocytes function normally in the recipient and are clinically effective.