The granulocytes in neutropenia 1 (GIN 1) study: a safety study of granulocytes collected from whole blood and stored in additive solution and plasma

Granulocyte transfusion during cord blood transplant for relapsed, refractory AML is associated with massive CD8+ T-cell expansion, significant cytokine release syndrome and induction of disease remission

In high-risk myeloid malignancy, relapse is reduced using cord blood transplant (CBT) but remains the principal cause of treatment failure. We previously described T-cell expansion in CBT recipients receiving granulocyte transfusions. We now report the safety and tolerability of such transfusions, T-cell expansion data, immunophenotype, cytokine profiles and clinical response in children with post-transplant relapsed acute leukaemia who received T-replete, HLA-mismatched CBT and pooled granulocytes within a phase I/II trial (ClinicalTrials.Gov NCT05425043). All patients received the transfusion schedule without significant clinical toxicity. Nine of ten patients treated had detectable measurable residual disease (MRD) pre-transplant. Nine patients achieved haematological remission, and eight became MRD negative. There were five deaths: transplant complications (n = 2), disease (n = 3), including two late relapses. Five patients are alive and in remission with 12.7 months median follow up. Significant T-cell expansion occurred in nine patients with a greater median lymphocyte count than a historical cohort between days 7-13 (median 1.73 × 109 /L vs. 0.1 × 109 /L; p < 0.0001). Expanded T-cells were predominantly CD8+ and effector memory or TEMRA phenotype. They exhibited markers of activation and cytotoxicity with interferon-gamma production. All patients developed grade 1-3 cytokine release syndrome (CRS) with elevated serum IL-6 and interferon-gamma.

How are granulocytes for transfusion best used? The past, the present and the future

Granulocyte transfusions continue to be used in clinical practice, predominantly for treatment of refractory infection in the setting of severe neutropenia. There is biological plausibility for effectiveness in these patients with deficiencies of neutrophils, either as a consequence of disease or treatment. However, there is a chequered history of conducting and completing interventional trials to define optimal use, and many uncertainties remain regarding schedule and dose. Practice and clinical studies are severely limited by the short shelf life and viability of current products, which often restricts the timely access to granulocyte transfusions. In the future, methods are needed to optimise donor-derived granulocyte products. Options include use of manufactured neutrophils, expanded and engineered from stem cells. Further possibilities include manipulation of neutrophils to enhance their function and/or longevity. Granulocyte transfusions contain a heterogeneous mix of cells, and there is additional interest in how these transfusions may have immunomodulatory effects, including for potential uses as adjuncts for anti-cancer effects.

ABO-incompatible granulocyte transfusion: Is ABO subgroup a barrier?

Granulocyte transfusion (GTx) is an efficient and compelling treatment option for patients with neutropenia following hematopoietic stem cell transplant. The donor pool for granulocyte harvest is limited to close friends and family members and the donors accepted are often of the same ABO Rh type. We report a case of ABO-incompatible prophylactic GTx, in a case of acute myeloblastic leukemia. Postcollection processing of the granulocyte product was done to reduce the red blood cell volume to <5 ml, making it safe for transfusion. The transfusion was successful in stabilizing the total leukocyte counts in the patient. The patient was monitored, and there were no adverse reactions posttransfusion.

Granulocyte transfusions made with modified fluid gelatin in pediatric and adolescent patients with prolonged neutropenia

BACKGROUND

Granulocyte transfusions (GT) are used to treat progressive systemic or local infections in prolonged neutropenic patients with antibiotic or antifungal resistance. Granulocytes are most commonly collected from whole blood by apheresis using hydroxyethyl starch (HES) as the red blood cell (RBC) sedimentation agent. This is the first study on the safety and efficacy of transfusing granulocytes collected with modified fluid gelatin (MFG) instead of HES to pediatric patients.

METHODS

Clinical data from 46 pediatric and adolescent patients receiving at least one MFG-based granulocyte transfusion and in total 295 granulocyte concentrates from July 2013 to August 2019 at our local university medical center were evaluated retrospectively.

RESULTS

Forty-one patients (89%) survived at least 21 days after their last granulocyte transfusion. These survivors had lower CRP values and higher leukocyte counts after GT than non-survivors (mean delta of -5.34 mg/dl vs. -11.99 mg/dl and + 0.62 × 10³ /μl vs. +0.18 × 10³ /μl of all GT, respectively). The neutrophil corrected count increment (CCI) was 68.72 mm² /ml in survivors versus 28.00 mm² /ml in non-survivors. There were no major or severe adverse events.

CONCLUSION

This study suggests that modified fluid gelatin is a safe and effective alternative to hydroxyethyl starch for the collection of granulocytes for transfusion to prolonged neutropenic patients with progressive systemic or local infections refractory to antibiotic or antifungal therapy.

Granulocyte Transfusion: Clinical Updates and a Practical Approach to Transfusion

Neutrophils are an integral component of the innate immune system and key regulators of cell-mediated defense against bacterial and fungal pathogens. The potential of granulocyte transfusions has been investigated to temporarily replenish innate immune function to prevent and/or treat infections in patients with severe neutropenia or neutrophil dysfunction. However, evidence has been largely theoretical, experimental, and/or inconclusive. Clinical efficacy has yet to be confirmed by large-scale randomized controlled clinical trials. Performing such trials has been hampered by low granulocyte collection yield and poor patient accrual. We provide a practical summary of the current literature surrounding the practice of granulocyte transfusion.

Directed Donation: Special Considerations and Review for Contemporary Clinical Practices

Background: Directed blood donation is defined as the donation of blood or its components for the purpose of transfusion into a specified individual. Directed blood donation holds historic significance, and although practices as of 2021 encourage voluntary, nonrenumerated blood donations, public interest in directed donation remains. Requests to discuss the risks and benefits of directed donations are a common inquiry for transfusion medicine, transplant, and hematology/oncology professionals. This narrative review discusses the history of directed donation and summarizes directed donation considerations in the context of modern transfusion practices. Methods: We conducted a systematic search of PubMed for published literature on the topic of directed blood donation and gathered information about its benefits and potential harms with respect to the variety of products used in transfusion medicine. Results: The drawbacks of directed donation include transfusion-transmitted infection risk, alloimmunization risk, increased transfusion-associated graft vs host disease risk, decreased expediency in treatment, and increased administrative burdens. However, a role remains for directed blood donation in specific patient populations, such as individuals with rare blood types or immunoglobulin A deficiencies, because of the difficulties in finding compatible blood for transfusion. Conclusion: Clinicians should consider the risks and benefits when discussing directed blood donations with patients and family members.

Granulocyte concentrates prepared from residual leukocyte units produced by the Reveos automated blood processing system

BACKGROUND

Granulocyte concentrates are mainly derived by apheresis technique from donors stimulated with granulocyte colony-stimulating factor and steroids. The automated blood processing system Reveos, which is now increasingly used across the world, separates whole blood into four components, including a residual leukocyte unit containing granulocytes. The aim of this study was to produce an alternative granulocyte concentrate from leukocyte units produced by the Reveos system, and to assess the function of the granulocytes.

METHODS

The number of granulocytes was measured in residual leukocyte units, derived from whole blood donations, with different volumes ranging from 10 to 40 ml. After deciding the optimal volume of the leukocyte unit (30 ml), ten ABO-matched units were pooled to form a granulocyte concentrate. The function of the granulocytes from residual leukocyte units was assessed by analyzing surface markers, phagocytosis of yeast, and production of reactive oxygen species.

RESULTS

Residual leukocyte units with a volume of 30 ml contained a median number of 0,7 × 10⁹ granulocytes, and granulocyte concentrates prepared from ten pooled 30 ml-leukocyte units contained a median number of 6,3 × 10⁹ granulocytes. Granulocytes derived from residual leukocyte units displayed surface markers associated with granulocyte function, and capability to phagocytose yeast and produce reactive oxygen species.

CONCLUSIONS

Granulocyte concentrates prepared from residual leukocyte units contain in vitro functional granulocytes and may be considered as an alternative product in acute situations before regular granulocyte concentrates from stimulated donors are available.

[Preparation of pooled granulocytes concentrates from whole blood buffy coats (PGC) as an alternative to apheresis]

BACKGROUND

The collection of granulocytes by apheresis requires volunteer donor stimulation by corticoids and the use of HES, a compound which is currently challenged by potential safety issues. Preparation of pooled granulocytes concentrates from whole blood buffy coats (PGC) represent an alternative to apheresis with a better benefit/risk for the donors.

METHOD

Whole blood is collected in a bottom and top blood bag for buffy coat preparation. After centrifugation and separation, buffy coat are obtained. Twenty ABO matched buffy coats are selected for processing into one PGC. Four pools of five buffy coats were made, platelet additive solution is added to each pool, mixed gently and centrifuged. The red cell residue, supernatant and granulocyte rich layer are separated. Two granulocyte rich layers are pooled and added with 70mL of ABO matched plasma from the initial donations (=PGC10). The final PGC (=PGC20) is obtained by pooling two PGC10 into a platelet storage bag. Neutrophil content and in-vitro functionality are assessed at day of preparation (D1) and at expiry hour, 48 hours after collection (D2).

RESULTS

On N=18, mean: Volume=408±4mL, 2.2*1010±0.24 neutrophils, Hematocrit=18%±3%, 4.7*1011platelets. Viability is well preserved: 95%±6% day of PGC preparation, 85%±7% after 24h of storage (D2). Functionality (ROS production measurement) is well preserved: 1.36±0.25 at D1 and 1.38±0.18 at D2. Expression and modulation of adhesion molecules after stimulation are normal at D1 and slightly decreased at D2 but still normal.

CONCLUSIONS

PGC20 in vitro characteristics are in conformance with the EDQM guide (V19) and similar to apheresis for granulocytes content and hematocrit. The viability and two mean indicators which explore neutrophil function are well maintained during PGC preparation and after 24 hours of storage.

Role of granulocyte transfusions in combating life-threatening infections in patients with severe neutropenia: Experience from a tertiary care centre in North India

Bacterial and fungal infections still remain an important cause of mortality in patients with hematological malignancies and in recipients of hematopoietic stem cell transplants (HSCT) especially in developing countries like India. Granulocyte transfusions (GTX) from healthy donors may lead to early clearance of index infection and thus prevent mortality. The aim of the present study was to evaluate the efficacy of GTX in combating life-threatening infections and preventing mortality in patients of hematological disorders/recipients of HSCT with severe neutropenia. This study was a prospective, observational analysis of patients with different hematological disorders/recipients of HSCT, who received GTX from January 2014 to December 2017. All patients had an Absolute neutrophil Count (ANC) < 0.5 x 109/L and a life threatening sepsis defined by presence of hemodynamic instability/ impending septic shock/ continuous high fever despite the use of the highest line of antimicrobials. A total of 143 granulocyte collections were done for 66 infectious episodes (IEs) in 60 patients. Multidrug resistant organisms (MDROs) were observed in 47/66 IEs (71.2%) and fungal infections were seen in 9/66 IEs (13.6%). Resolution of index infection after GTX was seen in 45/66 IEs (68.2%), and the 30 day overall survival (OS) was 67.7%. OS was significantly higher in patients who received GTX within 7 days of neutropenic sepsis (p = 0.01). Patients with MDROs who received early GTX therapy had a better OS as compared to those who received late GTX (p = 0.02). GTX were well tolerated and only 6 patients' developed mild features of transfusion related acute lung injury (TRALI) which was managed conservatively, and 1 patient demonstrated hypocalcemic tetany. GTX may be of particular relevance in countries like India, where the incidence of infections is very high in neutropenic patients and there is an increasing emergence of MDROs.

An International Registry of Granulocyte Transfusions

Introduction

Granulocyte transfusions are used to either treat or prevent life-threatening infections in neutropenic patients. Current evidence from clinical trials does not support or reject efficacy, nor guide practice.

Methods

A group of investigators have led the efforts to create an online registry to gather information on granulocyte transfusion practices from as broad a range of international settings. The data forms were adapted from an on-going study in England for electronic data management. Data is collected at the time of the request for granulocytes, weekly, at 28 days, and at 6 months. Information collected includes donor, granulocyte unit, patient and illness characteristics, and outcomes.

Results

The PROspective GRanulocyte usage and outcomEs Survey (ProGrES) is currently open for data entry. Centres across the UK have collected data on 80 subjects. Five institutions from 4 countries (2 from the US, 1 each from Brazil, and national services in Canada and France) are in the process of joining the study. Other countries have expressed interest.

Conclusion

It is feasible to develop an international registry of granulocyte transfusions to characterise current practices and describe outcomes. This registry would provide a platform to explore the relationship between intervention and outcomes, and to generate evidence to inform granulocyte transfusion efficacy.

Granulocyte transfusions: A concise review for practitioners

Granulocyte transfusions (GTXs) have been used to treat and prevent infections in neutropenic patients for more than 40 years, despite persistent controversy regarding their efficacy. This narrative review attempts to complement recent systematic reviews by the Cochrane Collaboration and provide both historical context and critical assessment of the most significant clinical studies published over the years. The data suggest that properly collected and promptly infused granulocytes are active against infections, both bacterial and fungal. The most important question that remains unanswered is in which patients the administration of granulocytes will be beneficial. The preponderance of evidence suggests that granulocyte transfusions may be efficacious in few select cases as a temporizing measure to control an infection that is expected (or proven) to be refractory to optimal antimicrobial treatment, and that could otherwise be controlled by marrow recovery, which is expected to happen. In this regard, they are best considered a "bridge" that grants enough time for the recipient to develop their own response to the infection. The challenges to use GTXs successfully are both clinical, in terms of timely identifying the patients who may benefit, and logistical, in terms of optimal selection of donors and collection technique.

Characterization of buffy coat-derived granulocytes for clinical use: a comparison with granulocyte colony-stimulating factor/dexamethasone-pretreated donor-derived products

BACKGROUND AND OBJECTIVES

Buffy coat-derived granulocytes have been described as an alternative to the apheresis product from donors pretreated with dexamethasone and granulocyte colony-stimulating factor (G-CSF). The latter is - dependent on the local and national settings - obtained following a demanding and time-consuming procedure, which is undesirable in critically ill septic patients. In contrast, buffy coat-derived products have a large volume and are often heavily contaminated with red cells and platelets. We developed a new pooled buffy coat-derived product with high purity and small volume, and performed a comprehensive functional characterization of these granulocytes.

MATERIALS AND METHODS

We pooled ten buffy coats following the production of platelet concentrates. Saline 0·9% was added to decrease the viscosity and the product was split into plasma, red cells and a 'super' buffy coat. Functional data of the granulocytes were compared to those obtained with granulocytes from healthy controls and G-CSF/dexamethasone-pretreated donors.

RESULTS

Buffy coat-derived granulocytes showed adhesion, chemotaxis, reactive oxygen species production, degranulation, NETosis and in vitro killing of Staphylococcus aureus, Escherichia coli and Aspergillus species comparable to control and G-CSF/dexamethasone-derived granulocytes. Candida killing was superior compared to G-CSF/dexamethasone-derived granulocytes. Immunophenotyping was normal; especially no signs of activation in the buffy coat-derived granulocytes were seen. Viability was reduced. Buffy coats are readily available in the regular blood production process and would take away the concerns around the apheresis product.

CONCLUSION

The product described appears a promising alternative for transfusion purposes.

Granulocyte transfusions for treating infections in people with neutropenia or neutrophil dysfunction

BACKGROUND

Despite modern antimicrobials and supportive therapy bacterial and fungal infections are still major complications in people with prolonged disease-related or treatment-related neutropenia. Transfusions of granulocytes have a long history of usage in clinical practice to support and treat severe infection in high-risk groups of patients with neutropenia or neutrophil dysfunction. However, there is considerable current variability in therapeutic granulocyte transfusion practice, and uncertainty about the beneficial effect of transfusions given as an adjunct to antibiotics on mortality. This is an update of a Cochrane review first published in 2005.

OBJECTIVES

To determine the effectiveness and safety of granulocyte transfusions compared to no granulocyte transfusions as adjuncts to antimicrobials for treating infections in people with neutropenia or disorders of neutrophil function aimed at reducing mortality and other adverse outcomes related to infection.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 2). MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1980) and ongoing trial databases to 11 February 2016.

SELECTION CRITERIA

RCTs comparing people with neutropenia or disorders of neutrophil dysfunction receiving granulocyte transfusions to treat infection with a control group receiving no granulocyte transfusions. Neonates are the subject of another Cochrane review and were excluded from this review. There was no restriction by outcomes examined, language or publication status.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

We identified 10 trials that met the inclusion criteria with a total of 587 participants. We also identified another ongoing trial. These trials were conducted between 1975 and 2015. None of the studies included people with neutrophil dysfunction. The studies differed in the type of infections they included. Six studies included both children and adults, however data were not reported separately for children and adults. The two newest studies gave granulocyte colony stimulating factor (G-CSF) to donors; both were stopped early due to lack of recruitment. Three studies re-randomised participants and therefore quantitative analysis was unable to be performed.Overall the quality of the evidence was very low to low across different outcomes according to GRADE methodology. This was due to many of the studies being at high risk of bias, and many of the outcomes being imprecise.There may be no difference in all-cause mortality over 30 days between participants receiving therapeutic granulocyte transfusions and those that did not (six studies; 321 participants; RR 0.75, 95% CI 0.54 to 1.04; very low-quality evidence). There were no differences between the granulocyte dose subgroups (< 1 x 10(10) per day versus ≥ 1 x 10(10) per day) (test for subgroup differences P = 0.39). There was a difference in all-cause mortality between the studies based on the age of the study (published before 2000 versus published 2000 or later) (test for subgroup differences P = 0.03). There was no difference in all-cause mortality between participants receiving granulocyte transfusions and those that did not in the newest study (one study; 111 participants; RR 1.10, 95% CI 0.70 to 1.73, low-quality evidence). There may be a reduction in all-cause mortality in participants receiving granulocyte transfusions compared to those that did not in studies published before the year 2000 (five studies; 210 participants; RR 0.53, 95% CI 0.33 to 0.85; low-quality evidence).There may be no difference in clinical reversal of concurrent infection between participants receiving therapeutic granulocyte transfusions and those that did not (five studies; 286 participants; RR 0.98, 95% CI 0.81 to 1.19; low-quality evidence).There is insufficient evidence to determine whether there is a difference in pulmonary serious adverse events (1 study; 24 participants; RR 0.85, 95% CI 0.38 to 1.88; very low-quality evidence).None of the studies reported number of days on therapeutic antibiotics, number of adverse events requiring discontinuation of treatment, or quality of life.Six studies reported their funding sources and all were funded by governments or charities.

AUTHORS' CONCLUSIONS

In people who are neutropenic due to myelosuppressive chemotherapy or a haematopoietic stem cell transplant, there is insufficient evidence to determine whether granulocyte transfusions affect all-cause mortality. To be able to detect a decrease in all-cause mortality from 35% to 30% would require a study containing at least 2748 participants (80% power, 5% significance). There is low-grade evidence that therapeutic granulocyte transfusions may not increase the number of participants with clinical resolution of an infection.

Granulocyte transfusions in children and adults with hematological malignancies: benefits and controversies

Bacterial and fungal infections continue to pose a major clinical challenge in patients with prolonged severe neutropenia after chemotherapy or hematopoietic stem cell transplantation (HSCT). With the advent of granulocyte colony-stimulating factor (G-CSF) to mobilize neutrophils in healthy donors, granulocyte transfusions have been broadly used to prevent and/or treat life-threatening infections in patients with severe febrile neutropenia and/or neutrophil dysfunction. Although the results of randomized controlled trials are inconclusive, there are suggestions from pilot and retrospective studies that granulocyte transfusions may benefit selected categories of patients. We will critically appraise the evidence related to the use of therapeutic granulocyte transfusions in children and adults, highlighting current controversies in the field and discussing complementary approaches to modulate phagocyte function in the host.

Granulocyte transfusions for preventing infections in people with neutropenia or neutrophil dysfunction

BACKGROUND

Despite modern antimicrobials and supportive therapy, bacterial and fungal infections are still major complications in people with prolonged disease-related or therapy-related neutropenia. Since the late 1990s there has been increasing demand for donated granulocyte transfusions to treat or prevent severe infections in people who lack their own functional granulocytes. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To determine the effectiveness and safety of prophylactic granulocyte transfusions compared with a control population not receiving this intervention for preventing all-cause mortality, mortality due to infection, and evidence of infection due to infection or due to any other cause in people with neutropenia or disorders of neutrophil function.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) and quasi-RCTs in the Cochrane Central Register of Controlled Trials (Cochrane Library 2015, Issue 3), MEDLINE (from 1946), EMBASE (from 1974), CINAHL (from 1937), theTransfusion Evidence Library (from 1980) and ongoing trial databases to April 20 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing people receiving granulocyte transfusions to prevent the development of infection with a control group receiving no granulocyte transfusions. Neonates are the subject of another Cochrane review and were excluded from this review. There was no restriction by outcomes examined, but this review focuses on mortality, mortality due to infection and adverse events.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Twelve trials met the inclusion criteria. One trial is still ongoing, leaving a total of 11 trials eligible involving 653 participants. These trials were conducted between 1978 and 2006 and enrolled participants from fairly comparable patient populations. None of the studies included people with neutrophil dysfunction. Ten studies included only adults, and two studies included children and adults. Ten of these studies contained separate data for each arm and were able to be critically appraised. One study re-randomised people and therefore quantitative analysis was unable to be performed.Overall, the quality of the evidence was very low to low across different outcomes according to GRADE methodology. This was due to many of the studies being at high risk of bias, and many of the outcome estimates being imprecise.All-cause mortality was reported for nine studies (609 participants). There was no difference in all-cause mortality over 30 days between people receiving prophylactic granulocyte transfusions and those that did not (seven studies; 437 participants; RR 0.92, 95% CI 0.63 to 1.36, very low-quality evidence).Mortality due to infection was reported for seven studies (398 participants). There was no difference in mortality due to infection over 30 days between people receiving prophylactic granulocyte transfusions and those that did not (six studies; 286 participants; RR 0.69, 95% CI 0.33 to 1.44, very low-quality evidence).The number of people with localised or systemic bacterial or fungal infections was reported for nine studies (609 participants). There were differences between the granulocyte dose subgroups (test for subgroup differences P = 0.01). There was no difference in the number of people with infections over 30 days between people receiving prophylactic granulocyte transfusions and those that did not in the low-dose granulocyte group (< 1.0 x 10(10) granulocytes per day) (four studies, 204 participants; RR 0.84, 95% CI 0.58 to 1.20; very low-quality evidence). There was a decreased number of people with infections over 30 days in the people receiving prophylactic granulocyte transfusions in the intermediate-dose granulocyte group (1.0 x 10(10) to 4.0 x 10(10) granulocytes per day) (4 studies; 293 participants; RR 0.40, 95% CI 0.26 to 0.63, low-quality evidence).There was a decreased number of participants with bacteraemia and fungaemia in the participants receiving prophylactic granulocyte transfusions (nine studies; 609 participants; RR 0.45, 95% CI 0.30 to 0.65, low-quality evidence).There was no difference in the number of participants with localised bacterial or fungal infection in the participants receiving prophylactic granulocyte transfusions (six studies; 296 participants; RR 0.75, 95% CI 0.50 to 1.14; very low-quality evidence).Serious adverse events were only reported for participants receiving granulocyte transfusions and donors of granulocyte transfusions.

AUTHORS' CONCLUSIONS

In people who are neutropenic due to myelosuppressive chemotherapy or a haematopoietic stem cell transplant, there is low-grade evidence that prophylactic granulocyte transfusions decrease the risk of bacteraemia or fungaemia. There is low-grade evidence that the effect of prophylactic granulocyte transfusions may be dose-dependent, a dose of at least 10 x 10(10) per day being more effective at decreasing the risk of infection. There is insufficient evidence to determine any difference in mortality rates due to infection, all-cause mortality, or serious adverse events.

Blood banking/immunohematology: special relevance to pediatric patients

Blood banking/immunohematology is an area of laboratory medicine that involves the preparation of blood and blood components for transfusion as well as the selection and monitoring of those components following transfusion. The preparation, modification, and indications of both traditional and newer products are described in this review, along with special considerations for neonates, patients undergoing hematopoietic stem cell transplantation, those with sickle cell disease, and others. Immunohematological techniques are critical in the provision of blood and blood products and are briefly discussed.

Granulocyte Transfusion Therapy

Bacterial and fungal infections continue to be a major cause of morbidity and mortality in severely neutropenic patients undergoing aggressive chemotherapy regimens or hematopoietic stem cell transplantation. Traditional granulocyte transfusion therapy, a logical approach in treating these infections, has been available for many years, and several controlled studies have shown this therapy to be useful. However, granulocyte transfusion therapy fell out of favor because the results were not clinically impressive, and adverse results were reported. These disappointing results were felt to be, in part, because of the low doses of granulocytes provided. More recent studies have attempted to increase the numbers of transfused cells by stimulating normal granulocyte donors with G-CSF (+/-corticosteroids). With these techniques, the number of granulocytes transfused can be increased 3-4 fold. The cells have been shown to circulate in recipients, and daily transfusions are capable of maintaining normal or near-normal blood neutrophil counts in previously severely neutropenic patients. The cells appear to function normally by a variety of in vitro and in vivo tests. Clinical benefit, as defined by survival or clearance of infection, has not been definitively determined. Results of an ongoing randomized controlled clinical trial should be available in the near future.