Transfusion of granulocyte rich buffy coats to neutropenic patients

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.

Granulocyte transfusions for neonates with confirmed or suspected sepsis and neutropenia

BACKGROUND

Neonates have immature granulopoiesis, which frequently results in neutropenia after sepsis. Neutropaenic septic neonates have a higher mortality than non-neutropenic septic neonates. Therefore, granulocyte transfusion to septic neutropenic neonates may improve outcomes.

OBJECTIVES

The primary objective was to determine the effect of granulocyte or buffy coat transfusions as adjuncts to antibiotics, after confirmed or suspected sepsis in neutropenic neonates, on all-cause mortality during hospital stay and neurological outcome at ≥ year of age. Secondary objectives were to determine the effects of granulocyte transfusions on length of hospital stay in survivors to discharge, adverse effects and immunologic outcomes at ≥ year of age.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE and CINAHL, proceedings of the PAS conferences and ongoing trials at clinicaltrials.gov and clinical-trials.com were searched in July 2011.

SELECTION CRITERIA

Studies where neutropenic neonates with suspected or confirmed sepsis were randomised or quasi-randomised to granulocyte or buffy coat transfusions at any dose or duration, and reporting any outcome of interest were included.

DATA COLLECTION AND ANALYSIS

Relative risk (RR) and risk difference (RD) with 95% confidence intervals using the fixed effects model were reported for dichotomous outcomes. Pre-specified subgroup analyses were performed.

MAIN RESULTS

Four trials were eligible for inclusion. Forty-four infants with sepsis and neutropenia were randomised in three trials to granulocyte transfusions or placebo/no transfusion. In another trial, 35 infants with sepsis and neutropenia on antibiotics were randomised to granulocyte transfusion or IVIG.When granulocyte transfusion was compared with placebo or no transfusion, there was no significant difference in 'all-cause mortality' (three trials; typical RR 0.89, 95% CI 0.43 to 1.86; typical RD -0.05, 95% CI -0.31 to 0.21).When granulocyte transfusion was compared with intravenous immunoglobulin (one trial), there was a reduction in 'all-cause mortality' of borderline statistical significance (RR 0.06, 95% CI 0.00 to 1.04; RD -0.34, 95% CI -0.60 to -0.09; NNT 2.7, 95% CI 1.6 to 9.1).Pulmonary complications were the only adverse effect reported in the trials that used buffy coat transfusions. None of the trials reported on neurological outcome at one year of age or later, length of hospital stay in survivors to discharge or immunological outcome at one year of age or later.

AUTHORS' CONCLUSIONS

Currently, there is inconclusive evidence from randomised controlled trials (RCTs) to support or refute the routine use of granulocyte transfusions in neutropenic, septic neonates. Researchers are encouraged to conduct adequately powered multi-centre trials of granulocyte transfusions in neutropenic septic neonates.

The use of blood products in perinatal medicine

Fetal and neonatal medicine is a field with many new procedures and techniques. An increasing number of centres worldwide give intrauterine transfusions, which are considered to be standard-of-care treatment for severe fetal anaemia. The survival of very prematurely born neonates, in particular of a gestational age of <28 weeks, has greatly improved over the last decade but almost all these children need transfusions. Although in many cases such blood transfusions are life saving, randomized, controlled studies investigating appropriate indications, transfusion volume and type of blood product have not been performed. Most of the protocols used are expert based.

Granulocyte transfusions for neonates with confirmed or suspected sepsis and neutropaenia

BACKGROUND

Neonatal sepsis causes significant neonatal mortality and morbidity. Neonates, especially preterm infants, have an immaturity of granulopoeisis and have a limited capacity for progenitor cell proliferation. This results in the frequent occurrence of neutropaenia in septic neonates. Neutropaenic septic neonates have a higher mortality than neonates who are septic but not neutropaenic. Transfusion of granulocytes to septic neutropaenic neonates, therefore, may help reduce mortality and morbidity.

OBJECTIVES

The primary objective of this review was to determine the efficacy and safety of granulocyte preparations (granulocyte and buffy coat transfusions) as adjuncts to antibiotics for the treatment of confirmed or suspected sepsis in neonates with neutropaenia in reducing all-cause mortality during hospital stay and adverse neurological outcome at a year of age or later. Secondary objectives were to determine the effects of granulocyte transfusions on length of hospital stay in survivors to discharge, adverse effects (fluid overload, transmission of blood borne infections, pulmonary complications and sensitisation to donor leukocyte antigens) and immunologic outcomes at a year of age or later.

SEARCH STRATEGY

Searches for eligible trials were made in September 2002 of the following electronic databases: The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2002), MEDLINE, EMBASE, CINAHL. The proceedings of the Pediatric Academic Societies, which were published in the journal, Pediatric Research, were searched from 1987 onwards. The Cambridge Database of Scientific Abstracts (1982 onwards) and Dissertation Abstracts on disc (1960 onwards) were also searched. Communications with prominent authors in the field and additional searches in the reference lists of identified trials were performed

SELECTION CRITERIA

Randomised and quasi-randomised studies were included, if the participants were neonates with suspected or confirmed sepsis and neutropaenia who received granulocyte preparations (granulocyte concentrates prepared by leukophoresis or buffy coat transfusions prepared by simple centrifugation of blood) at any dose or duration compared with placebo or no granulocyte transfusion, each as adjuncts to antibiotics or compared to other adjuncts to antibiotics to treat sepsis (e.g. intravenous immunoglobulin). Studies were included if any of the following outcomes were reported: all-cause mortality during hospital stay, neurological outcome at one year of age or later, length of hospital stay in survivors at discharge, adverse effects or immunological outcome at one year or later

DATA COLLECTION AND ANALYSIS

Trials identified by the search strategy were assessed for eligibility for inclusion in the review. Full text versions of the eligible trials were obtained. Data of interest were extracted on paper forms. Relative risk (RR) and risk difference (RD) with 95% confidence intervals using the fixed effects model were reported for dichotomous outcomes. Pre-specified subgroup analyses were done and reported.

MAIN RESULTS

Four eligible studies were identified. A total of 44 infants with sepsis and neutropaenia on antibiotics were randomised in three trials to granulocyte transfusions OR placebo/no transfusion. In another trial, 35 infants with sepsis and neutropaenia on antibiotics were randomised to granulocyte transfusion or intravenous immunoglobulin. When granulocyte transfusions were compared with placebo or no transfusion, there was no significant difference in all-cause mortality [typical RR 0.89 (95% CI 0.43, 1.86), typical RD -0.05 (95% CI -0.31, 0.21)]. There was no statistical heterogeneity in the results of the included trials. When granulocyte transfusions were compared with intravenous immunoglobulin, there was a reduction in all-cause mortality of borderline statistical significance [RR 0.06 (95% CI 0.00, 1.04), RD -0.34(95% CI -0.60, -0.09), NNT 2.9 (95% CI 1.7, 11.1)]. Pulmonary complication, seen in four infants (4%), was the only adverse effect reported. This adverse effect was noticed in the two trials which used buffy coat transfusions. None of the trials reported on neurological outcome at one year of age or later, length of hospital stay in survivors to discharge or immunological outcome at one year of age or later.

REVIEWER'S CONCLUSIONS

Currently, there is inconclusive evidence from RCTs to support or refute the routine use of granulocyte transfusions in neonates with sepsis and neutropaenia to reduce mortality and morbidity. Researchers can be encouraged to conduct adequately powered multicentre trials of granulocyte transfusions to clarify their role in neonates with sepsis and neutropaenia. Other adjuncts to antibiotics aimed at improving host defence mechanisms such as colony stimulating factors, IVIG and pentoxifylline should also be tested in RCTs.

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.