WBC alloimmunization: effects on the laboratory and clinical endpoints of therapeutic granulocyte transfusions
BACKGROUND Although the subject of many previous studies, the importance of white blood cell (WBC) alloimmunization in granulocyte transfusion therapy has not been settled. In this study, we report the results of the effects of WBC antibodies in the RING (Resolving Infection in Neutropenia with Granulocytes) study, a randomized controlled trial comparing the efficacy of daily granulocyte transfusion therapy plus antimicrobials versus antimicrobials alone; the primary outcome results have been published previously. STUDY DESIGN AND METHODS One hundred fourteen subjects were enrolled in the study. Serum samples for WBC antibody determination were obtained from each subject at baseline and at 2 and 6 weeks. One hundred subjects had at least one antibody test result. Samples were tested for human leukocyte antigen (HLA) Class I and Class II antibodies as well as for granulocyte-specific antibodies using granulocyte agglutination and immunofluorescence techniques. All testing was performed at a central laboratory. RESULTS Baseline WBC alloimmunization was modest, depending somewhat on the assay. Seroconversion during the study was slightly higher in the granulocyte transfusion arm, but the differences were not statistically significant. There was no demonstrable effect of the presence of alloimmunization on the primary outcome (survival and microbial response at 42 days), the occurrence of transfusion reactions (either overall or pulmonary), or posttransfusion neutrophil increments. CONCLUSION The presence or development of WBC antibodies had no demonstrable effect on any clinical aspect of granulocyte transfusion therapy. It appears that, at least in the patient population studied, there is no evidence suggesting need for concern about recipient WBC alloimmunization when prescribing granulocyte transfusions.
Efficacy of transfusion with granulocytes from G-CSF/dexamethasone-treated donors in neutropenic patients with infection
High-dose granulocyte transfusion therapy has been available for 20 years, yet its clinical efficacy has never been conclusively demonstrated. We report here the results of RING (Resolving Infection in Neutropenia with Granulocytes), a multicenter randomized controlled trial designed to address this question. Eligible subjects were those with neutropenia (absolute neutrophil count <500/muL) and proven/probable/presumed infection. Subjects were randomized to receive either (1) standard antimicrobial therapy or (2) standard antimicrobial therapy plus daily granulocyte transfusions from donors stimulated with granulocyte colony-stimulating factor (G-CSF) and dexamethasone. The primary end point was a composite of survival plus microbial response, at 42 days after randomization. Microbial response was determined by a blinded adjudication panel. Fifty-six subjects were randomized to the granulocyte arm and 58 to the control arm. Transfused subjects received a median of 5 transfusions. Mean transfusion dose was 54.9 x 10(9) granulocytes. Overall success rates were 42% and 43% for the granulocyte and control groups, respectively (P > .99), and 49% and 41%, respectively, for subjects who received their assigned treatments (P = .64). Success rates for granulocyte and control arms did not differ within any infection type. In a post hoc analysis, subjects who received an average dose per transfusion of >0.6 x 10(9) granulocytes per kilogram tended to have better outcomes than those receiving a lower dose. In conclusion, there was no overall effect of granulocyte transfusion on the primary outcome, but because enrollment was half that planned, power to detect a true beneficial effect was low. RING was registered at www.clinicaltrials.gov as #NCT00627393. Copyright © 2015 by The American Society of Hematology.
Buffy coat transfusions in early type I diabetes
Fresh whole-blood buffy coats from American Red Cross volunteers were used to treat early type I diabetes. Attempts were made to adapt to human diabetic patients a protocol successfully used in prediabetic BB rats. Twenty-two type I diabetic patients (duration of disease less than 4 wk) were randomized to treatment or control groups; the treatment patients were given one buffy coat (approximately 0.6 X 10(9) T-lymphocytes) weekly for 5 wk. Plasma C-peptide (stimulated and unstimulated), insulin dose, and hemoglobin A1c were measured before and periodically after the treatment for 24 wk. The control group underwent the same studies. Although there were no significant differences for the parameters studied between the two groups, 2 of 12 patients in the treatment group underwent three complete (normal glycemia without insulin) temporary remissions. One of these patients was given a second course of transfusions after relapse from the first remission and developed a second complete remission that lasted 2 mo. No control patient had remissions during the 24-wk study. Although the future of adoptive immunotherapy in the treatment or prevention of diabetes is not known, several probable limitations of the current protocol, as discussed here, can explain the differences in results between this trial and the rodent studies.