Granulocyte transfusion

PURPOSE OF REVIEW: Granulocyte transfusions have been used for more than four decades. Several issues have complicated the analysis of previous studies, including the utilization of improved antimicrobials, the effects of recipient alloimmunization and variable cell dose. The use of granulocyte colony-stimulating factor for donor stimulation has revived interest in granulocyte transfusion. The aim of this review is to evaluate the most recent studies in granulocyte transfusion therapy and their clinical applicability. RECENT FINDINGS: Granulocyte colony-stimulating factor use has increased the granulocyte yield by approximately fourfold. Multiple recent studies have shown that granulocyte transfusions can be helpful in controlling severe infections progressing despite the use of appropriate antibiotics, with a response rate of 40-80% with variability in results depending on patient characteristics. This benefit is limited to a small patient population as the incidence of prolonged reversible neutropenia is relatively small. Severe side effects have been rare in those studies. SUMMARY: Granulocyte transfusions are beneficial in neutropenic patients with severe uncontrolled infection. The underlying disease process is the major determinant of outcome in these patients. Because granulocyte transfusions are not commonly used, centers are not currently able to provide transfusions in a timely fashion. Nonalloimmunized patients can receive cells from nonmatched ABO compatible donors, while alloimmunized patients should receive granulocytes from either HLA-matched donors or donors selected by leukoagglutination or lymphocytotoxicity crossmatching. Further studies are needed to clarify the optimal starting time and frequency of transfusions, and the best method for identifying donor-recipient compatibility.     

Granulocyte transfusion: a review

Neutrophils are the body's main defence against invasion by bacteria and fungi and, below a level of 1 x 10(9)/l, there is a direct relationship between their circulating number and the risk of systemic infection. Despite advances in supportive care, such as improved broad-spectrum antibiotics and the haemopoietic growth factors, neutropenia following myelosuppressive chemotherapy for malignant disease remains the most important cause of treatment-related morbidity and mortality and its most important dose-limiting toxicity. Although there is clear theoretical, experimental and anecdotal clinical evidence supporting the use of transfused granulocytes to prevent and treat infection in neutropenia, early attempts at exploiting this clinically were unsuccessful, mainly because of difficulties in collecting a sufficient number of cells. Improvements in the technology of collection, including the use of red cell sedimenting agents, glucocorticoids and, more recently, granulocyte-colony-stimulating factor, now allow granulocyte doses within the therapeutic range to be routinely collected. Preliminary evidence suggests clinical efficacy. However, well-designed trials with clinically relevant end-points will be required before granulocyte transfusion can become part of routine clinical practice.     

Granulocyte transfusion: current status

Infection associated with therapy-related neutropenia continues to be a major cause of morbidity and mortality. Renewed interest in granulocyte transfusion therapy as treatment for this condition has been generated by the observation that large doses of granulocytes can be obtained from donors who have been stimulated with granulocyte colony-stimulating factor (G-CSF). Granulocytes collected from these donors have been shown to effectively raise the patient's neutrophil count and appear to function normally as judged both by in vitro and in vivo measures. The evidence for clinical efficacy is limited to that of case reports and small series, and the results are not uniform. Randomized controlled clinical trials are needed to determine whether this therapy is useful in either clearing infections or prolonging survival.     

Granulocyte transfusion in the G-CSF era

Granulocyte transfusions have been used since the 1960s with varying degrees of clinical success in the treatment of infection in patients with neutropenia or inherited granulocyte disorders. A number of studies have indicated that efficacy may well be associated with the dose of granulocytes delivered. Collection of granulocytes using modern apheresis machines and corticosteroid administration yields approximately 20～30×10⁹ neutrophils, unlikely to be adequate for treating an established infection. The administration of G-CSF to healthy donors has resulted in average granulocyte yields up to 8×10¹⁰ cells. Normal or near normal blood neutrophil counts are often attained when these concentrates are transfused to neutropenic recipients, and these levels are sustained for up to 24 h. G-CSF-primed granulocytes appear to be functionally normal by both in vitro and in vivo measurements. Adverse effects experienced by recipients are similar to those seen with traditional doses of granulocytes. G-CSF administration to donors is well tolerated. Controlled clinical trials are needed to determine the therapeutic efficacy of G-CSF-primed granulocyte transfusions.     

Granulocyte transfusion in the G-CSF era

Granulocyte transfusions have been used since the 1960s with varying degrees of clinical success in the treatment of infection in patients with neutropenia or inherited granulocyte disorders. A number of studies have indicated that efficacy may well be associated with the dose of granulocytes delivered. Collection of granulocytes using modern apheresis machines and corticosteroid administration yields approximately 20 to approximately 30 x 10(9) neutrophils, unlikely to be adequate for treating an established infection. The administration of G-CSF to healthy donors has resulted in average granulocyte yields up to 8 x 10(10) cells. Normal or near normal blood neutrophil counts are often attained when these concentrates are transfused to neutropenic recipients, and these levels are sustained for up to 24 h. G-CSF-primed granulocytes appear to be functionally normal by both in vitro and in vivo measurements. Adverse effects experienced by recipients are similar to those seen with traditional doses of granulocytes. G-CSF administration to donors is well tolerated. Controlled clinical trials are needed to determine the therapeutic efficacy of G-CSF-primed granulocyte transfusions.     

Granulocyte transfusion therapy: update on potential clinical applications

The clinical usefulness of granulocyte transfusions for treatment or prevention of life-threatening bacterial and fungal infections remains controversial. Clinical benefit has long been limited by insufficient donor stimulation regimens and suboptimal leukapheresis techniques. Methodologic progress, in particular mobilization of neutrophils in healthy donors by administration of G-CSF, has significantly enhanced leukapheresis yields. A newly published study indicates that unrelated community donors can be effectively and safely used as an alternative to related family donors. Furthermore, several recent studies suggest that it may be possible to store granulocyte concentrates for 24 to 48 hours with adequate preservation of neutrophil function. This review summarizes the current role of granulocyte transfusion therapy in infectious diseases and highlights important recent advances.     

Granulocyte transfusion therapy and amphotericin B: Adverse reactions?

One hundred twenty-five granulocyte transfusions were given concurrently with amphotericin B to 31 granulocytopenic patients with acute leukemia during a four year period. Twenty-six patients had culture-documented, and 5 had presumed fungal infections; pulmonary infiltrates were present in 26 patient courses. Eight patients developed pulmonary deterioration temporally related to therapy with amphotericin, granulocyte transfusions, or both. One event occurred following amphotericin alone. Three additional reactions occurred in alloimmunized patients with antibodies to human leukocyte antigens (HLA) who received random donor granulocytes, which may indicate a potential mechanism for the pulmonary reactions. Two reactions potentially represent an adverse interaction between amphotericin and granulocytes, but these were reversible and were not unlike reactions expected with each modality alone. Our data fail to document a specific detrimental interaction between granulocyte transfusions and amphotericin beyond the reactions associated with each modality, and the data suggest that other clinical factors, particularly infection and alloimmunization, also contribute to pulmonary decompensation. We nevertheless recommend great care and attention be given to administering these modalities in the setting of severely ill patients.     

ABO and platelet transfusion revisited

Summary Historically, ABO compatibility between donor and recipicnt has been considered of minor importance for platelet transfusion. However, in a recent ran-domized trial we showed that provision of only ABO-identical platelets was associated with a significantly higher corrected count increment (CCI) in the early transfusions and with a twofold reduction in refractoriness, as compared with platelets given unmatched for ABO. In older studies this phenomenon was not observed. We wondered whether in these previous studies the use of the conventional term ABO compatible, whereby ABO-identical platelet transfusions are grouped with those that are merely ABO compatible, might have obscured the advantages of the ABO-identical platelets. In this paper the CCI from our original study are compared with what would have been found had the conventional terminology of ABO compatible and ABO incompatible been used. In our original study the mean CCI in patients receiving only ABO-identical platelets was 64% higher than that achicved with ABO-unmatched products. However, when the transfusions were reanalyzed according to conventional terminology of ABO compatible and incompatible, the actual benefits of ABO-identical platelets were no longer detected. Thus, ha dwe used the conventional terminology in the original study we would have come to completely different conclusions about the importance of ABO in platelet transfusion. We hypothesize that transfusion of ABO-incompatible plasma leads to the formation of immune complexes that can destroy compatible platelets by indirect mechanisms. This model predicts that the success of a transfusion could be affected by previous incompatible transfusions. When transfusions were classificd as to whether they were first, second, or third unmatched transfusion, increasing numbers of transfusions of ABO-incompatible plasma were associated with progressively poorer mean increments. The same was true for platelet ABO-incompatible transfusions. In contrast, increasing numbers of ABO-identical transfusions were not associated with poorer increments. The failure to appreciate that (a) transfusions containing ABO-incompatible plasma yield poor increments and (b) the effects of ABO-nonidentical transfusions are cumulative, and therefore affect the success of subsequent identical transfusions, may have led in the past to the incorrect conclusion that ABO matching was of minor importance in repetitively transfused patients.Supported in part by funds from The American Red Cross     

Granulocyte dysfunction in transcobalamin II deficiency responding to leucovorin or hydroxocobalamin-plasma transfusion

Granulocytes from a 6-year-old boy with congenital transcobalamin II (TCII) deficiency were found to have abnormally low antibacterial activity againstStaphylococcus aureus and very low intracellular levels of the cobalamin coenzymes. Transfusion of hydroxocobalamin (OH-Cbl) bound to normal plasma temporarily restored granulocyte bactericidal activity and increased cellular levels of the cobalamin coenzymes. Granulocyte function was also temporarily restored by oral Leucovorin. The defect appeared to be causally related to the patient's TC II deficiency and indirectly to a deficiency of cobalamin and folate coenzymes.     

Granulocyte transfusions: current status

Since granulocyte transfusions first became widely used in clinical medicine, there have been advances in the treatment of acute leukemia and improvement in prevention and management of infection in neutropenic patients. Improved understanding now exists concerning prognosis of infections in such patients, and advances have been made in procurement of granulocytes. Granulocyte transfusions should be given for specific indications, and used adjunctively to other established antiinfective therapy. Once initiated, transfusions should be given in adequate doses at daily intervals (at least) with ongoing evaluation and periodic reassessment of the whole antiinfective program. Serious complications of granulocyte transfusion therapy are relatively rare, but the physician should be prepared to manage them intelligently. Research continues in discerning exactly how granulocyte transfusion work, in preservation of granulocytes, and in delineation of immunologic phenomena affecting the efficiacy of such therapy. Granulocyte transfusions will continue to be important in the management of acute leukemia, and other reversible bone marrow failure states, and in marrow transplantation and autotransplantation.     

Influence of Granulocyte Antibodies on Granulocyte Function

The following substances were tested for their influence on granulocyte function: 8 sera that contained human granulocyte-specific alloantibodies against the antigens NA1, NA2 and NB1, two HLA antisera, and the monoclonal antibodies W6/32 and CLB-FcR-gran 1. The effects examined included spontaneous and directed migration, immune phagocytosis inhibition and the generation of oxygen radicals. Using the under-agarose technique, spontaneous migration of sensitized granulocytes was normal. For all antibodies tested, the chemotactic index for N-fMLP, LTB₄ and opsonized zymosan was greater than 1. Granulocyte immune phagocytosis of sensitized sheep red blood cells was strongly inhibited by all alloantisera and monoclonal antibodies. The generation of oxygen radicals after triggering the respiratory burst with sensitized sheep red blood cells was also strongly inhibited in the chemiluminescence assay. Immune phagocytosis and chemiluminescent response of granulocytes lacking the corresponding antigen of the tested alloantibodies were not affected. Since sensitization of neutrophils with F(ab')₂ fragments of the monoclonal antibodies W6/32 and CLB-FcR-gran 1 showed lower inhibition of generation of oxygen radicals after triggering, Fc-dependent interaction with the target cells seems to be necessary for inhibition. Our results suggest that binding of NA1-, NA2- or NB1-specific alloantibodies to granulocytes not only causes neutropenia, but also impairs granulocyte function.     

Granulocyte transfusion as a treatment for enterococcal meningoencephalitis after allogeneic bone marrow transplantation from an unrelated donor

Bacterial meningoencephalitis occurring in the pre-engraftment period after bone marrow transplantation (BMT) is a rare complication, and the feasibility of granulocyte transfusion (GTX) in such cases remains to be elucidated. A 37-year-old man developed enterococcal meningoencephalitis during a severely granulocytopenic pre-engraftment period after BMT. Despite therapy with appropriate antibiotics, cultures of blood and cerebro-spinal fluid (CSF) continued to grow Enterococcus faecalis, and he developed rapid mental deterioration and seizure. Granulocytes were collected from his HLA-mismatched, ABO-matched sibling with subcutaneous injection of granulocyte colony-stimulating factor (G-CSF) and oral dexamethazone. Transfusion of 4.4 x 10(10) granulocytes resulted in a 12-h post-transfusion granulocyte increment of 2.0 x 10(9)/l, and maintained peripheral blood granulocyte counts above 0.5 x 10(9)/l for 3 days. A rapid increase of granulocytes in CSF was also observed, and cultures of blood and CSF became negative after GTX. A transient worsening of seizure was observed as a potential side effect of GTX. The patient subsequently developed septic shock because of Pseudomonas aeruginosa and died. Further studies are warranted to evaluate the clinical efficacy of GTX for the treatment of uncontrolled infections in granulocytopenic stem cell transplant recipients.     

Granulocyte transfusions

Laboratory and clinical studies have demonstrated beyond question that granulocyte transfusions can have a beneficial effect on the incidence and course of bacterial infection. The increment of improved survival produced by granulocyte transfusions depends on the effectiveness of the alternative (primarily antibiotic) therapy alone, and this varies with the pattern of bacterial predominance and sensitivity, which is notoriously changeable. The absolute effectiveness of granulocyte transfusion therapy is influenced by the quality of the transfusions and the immune status of both the recipient and the granulocyte donor. The indiscriminate transfusion of inadequate quantities of granulocytes from random donors into sensitized recipients should be discouraged. Severely neutropenic patients with established infection unresponsive to antibiotic therapy are appropriate recipients of granulocyte transfusions. Well-designed programs of prophylactic granulocyte transfusions can reduce the occurrence of bacterial infection in neutropenic patients, but there are few clinical situations in which their use is justified. The use of cytomegalovirus-seropositive granulocyte donors for cytomegalovirus-seronegative recipients should be avoided. There is a need for technical advances that will increase the ease and efficiency of granulocyte procurement.     

Granulocyte transfusions: Current science and perspectives

Severe neutropenia renders patients susceptible to life-threatening bacterial and fungal infections. Despite improvements in supportive care and antimicrobial therapy, morbidity and mortality remains significant. Since the 1960s, granulocyte transfusions have been used to either treat or prevent serious infections in patients with neutropenia or neutrophil dysfunction. Despite significant optimizations in product collection, the practice of granulocyte transfusion therapy remains controversial. The use of granulocytes varies widely across institutions and countries in terms of indications, procurement, dose, infusion frequency, and duration of therapy. There are limited and conflicting data concerning its clinical effectiveness; current evidence from clinical trials does not support or refute efficacy. In this narrative review, we summarize the current evidence, discuss persistent concerns and consider future possibilities of the role of granulocyte transfusions.