Granulocyte Transfusions for Treatment or Prophylaxis of Severe Infections in Immunocompromized Neutropenic Patients - A Randomized Clinical Trial.

Abstract

Background: Despite availability of potent anti-bacterial, anti-mycotic drugs and hematopoietic growth factors invasive bacterial or fungal infections remain a severe threat to neutropenic patients after chemotherapy or hematopoietic stem cell transplantation (HSCT). Granulocyte transfusions (GT) from granulocyte colony stimulating factor (G-CSF)-stimulated donors have been shown to increase the leukocyte count prior to expected hematopoietic regeneration, resulting in a shorter period of neutropenia and thus offer a therapeutic option for the control of severe infections. However, published studies rely on clinical observations of individual cases as no statistical comparison with control groups could have been established. The aim of this study was to define the clinical benefit and the leukocyte increment/duration of neutropenia after randomized administration of leukocyte transfusions in immunocompromized neutropenic patients.Patients and methods: Between 1999 and 2005 80 patients with underlying hematological diseases with or without allogeneic or autologous HSCT were randomized to receive either G-CSF, anti-infective treatment according to local standards with or without therapeutic or prophylactic application of GT from G-CSF-stimulated volunteer donors. The mean age was 47 years (range, 14 – 62 y). Indications were either fever in neutropenia and pulmonary infiltrates or soft tissue infiltration (therapeutic) or the history of invasive fungal infection during episodes of neutropenia following earlier chemotherapy courses and anticipated neutropenia of > 10 days (prophylactic).Results: 10 centers participated in the trial, however only five centers recruited patients (n=80) for randomization during the study period. This corresponds to ~50% of the expected sample size of 160 patients, hence results are statistically insignificant. Patient characteristics were comparable within the randomized cohorts (underlying disease, stage of disease, indication for GT, lenght of neutropenia). No significant difference in the clinical outcome was found between patients who received either therapeutic or prophylactic GT from G-CSF stimulated donors or no GT. The probability of survival on day 28 was 85% in both groups. Furthermore, no difference in the incidence and causes of death could be identified within the compared cohorts.Conclusion: The high percentage of infection clearance and survival in patients with severe infections in both groups contrasts with published results and own experiences. We speculate whether this is due a bias in including predominantly patients into the randomized study who presented with relatively favourable prognostic factors, as in the observation period numerous GT were performed in the participating centers without randomization. Most likely, existing clinical evidence for the benefit of this therapeutic measure was sufficient in many cases to exclude patients in serious conditions from randomization. Although well designed, a randomized trial may not always provide the expected results.