Effect of Donor Sex on Recipient Mortality in Transfusion.

BACKGROUND: Conflicting observational evidence exists regarding the association between the sex of red-cell donors and mortality among transfusion recipients. Evidence to inform transfusion practice and policy is limited. METHODS: In this multicenter, double-blind trial, we randomly assigned patients undergoing red-cell transfusion to receive units of red cells from either male donors or female donors. Patients maintained their trial-group assignment throughout the trial period, including during subsequent inpatient and outpatient encounters. Randomization was conducted in a 60:40 ratio (male donor group to female donor group) to match the historical allocation of red-cell units from the blood supplier. The primary outcome was survival, with the male donor group as the reference group. RESULTS: A total of 8719 patients underwent randomization before undergoing transfusion; 5190 patients were assigned to the male donor group, and 3529 to the female donor group. At baseline, the mean (±SD) age of the enrolled patients was 66.8±16.4 years. The setting of the first transfusion was as an inpatient in 6969 patients (79.9%), of whom 2942 (42.2%) had been admitted under a surgical service. The baseline hemoglobin level before transfusion was 79.5±19.7 g per liter, and patients received a mean of 5.4±10.5 units of red cells in the female donor group and 5.1±8.9 units in the male donor group (difference, 0.3 units; 95% confidence interval [CI], -0.1 to 0.7). Over the duration of the trial, 1141 patients in the female donor group and 1712 patients in the male donor group died. In the primary analysis of overall survival, the adjusted hazard ratio for death was 0.98 (95% CI, 0.91 to 1.06). CONCLUSIONS: This trial showed no significant difference in survival between a transfusion strategy involving red-cell units from female donors and a strategy involving red-cell units from male donors. (Funded by the Canadian Institutes of Health Research; iTADS ClinicalTrials.gov number, NCT03344887.).

Pragmatic, double-blind, randomised trial evaluating the impact of red blood cell donor sex on recipient mortality in an academic hospital population: the innovative Trial Assessing Donor Sex (iTADS) protocol.

INTRODUCTION: With over 1 million units of blood transfused each year in Canada, their use has a significant clinical and economic impact on our health system. Adequate screening of blood donors is important to ensure the safety and clinical benefit of blood products. Some adverse transfusion reactions have been shown to be related to donor factors (eg, lung injury), whereas other adverse outcomes have been theoretically related to donor factors (mortality and infection). Our clinical trial will test whether male donor blood leads to a greater benefit for transfusion recipients compared with female donor blood. METHODS AND ANALYSIS: We have designed a pragmatic, double-blind, randomised trial that will allocate transfusion recipients to receive either male-only or female-only donor transfusions. We will enrol 8850 adult patients requiring at least one transfusion at four sites over an approximate 2-year period. Randomisation and allocation will occur in the blood bank prior to release of the units of blood for transfusion. Our primary outcome is mortality. An intent-to-treat analysis will be applied using all randomised and transfused patients. The principal analysis will be a survival analysis comparing the time from randomisation to death between patients allocated to male donor red blood cells (RBCs) and female donor RBCs. ETHICS AND DISSEMINATION: Approval has been obtained from research ethics boards of all involved institutions, as well as from privacy offices of Canadian Blood Services, Institute for Clinical Evaluative Science and The Ottawa Hospital Data Warehouse. Our findings will be published in peer-reviewed journals and presented at relevant stakeholder conferences and meetings. TRIAL REGISTRATION NUMBER: NCT03344887; Pre-results.

Exploring Peaks in Hospital Blood Component Utilization: A 10-Year Retrospective Study at a Large Multisite Academic Centre.

Peak demand analysis is common in industries such as the energy sector, but can also be applied to the field of transfusion to characterize the nature and timing of peak days in hospital blood utilization. This information can be used to forecast future peak days or to inform hospital emergency preparedness plans. The aims of this study are to characterize peak days in red blood cell (RBC) utilization over the past 10 years at our hospital, and to compare RBC peaks with peaks in platelet, plasma, and cryoprecipitate utilization. This was a retrospective cohort study of RBC, platelet, plasma, and cryoprecipitate transfusions in the inpatient and emergency department setting between May 2009 and April 2019 at a large academic hospital, containing regional trauma and cardiovascular surgery centers. For each blood product, a peak in utilization was defined as a day with a ≥50% increase in the number of units transfused compared to the previous 90-day average. Descriptive and inferential analyses were performed to characterize peak days. There were on average 20,501 RBCs transfused per year and 56 RBCs transfused per day over the 10-year period. A total of 134 peaks in RBC utilization occurred over the study period, with an average of 14 peaks per year. RBC peak days required on average 69% more RBC units compared to nonpeak days (P< .0001). 77% of RBC peaks were caused either solely or in part by surgical bleeding, 34% were caused entirely or in part by trauma, and other causes were infrequent. RBC peaks occurred most often on Fridays and least often on weekends (P< .0001). While there were 134 RBC peaks over the study period, there was a larger number of platelet (n = 292), plasma (n = 467), and cryoprecipitate peaks (n = 579). RBC peak days often coincided with plasma peak days, but less frequently with platelet and cryoprecipitate peaks. More studies are needed to determine whether analysis of peak usage will be of value to hospital blood banks for emergency planning and blood inventory management.

Activated prothrombin complex concentrates for direct oral anticoagulant-associated bleeding or urgent surgery: Hemostatic and thrombotic outcomes.

INTRODUCTION: Studies evaluating the use of activated prothrombin complex concentrates (aPCCs) for DOAC-associated bleeding are sparse. MATERIALS AND METHODS: We conducted a retrospective study of patients receiving aPCC for DOAC-associated bleeding or for pre-operative optimization of hemostasis prior to urgent surgery. The primary efficacy outcome was hemostatic efficacy, the primary safety outcome was the 30-day thromboembolic complication rate. RESULTS: Eighty-two patients were included in the analysis; 14 patients on dabigatran, 39 patients on rivaroxaban and 29 patients on apixaban. Fifty-four patients received aPCC for major bleeding and 28 patients prior to urgent surgery. Mean aPCC dosing was 2974 IU (SD ± 857 IU). Hemostasis was deemed effective by ISTH criteria in 50% of cases and "Good" or "Moderate" by Sarode criteria in 45.2% and 14.3% of cases, respectively. Surgical hemostasis was rated as "Normal" in 84% of cases pre-operative administration. Median pre-aPCC INR was 1.6 (IQR 0.5) and median post-aPCC INR was 1.2 (IQR 0.2) (p < 0.00001). Median pre-aPCC aPTT was 36 s (IQR 12.8), median post-aPCC aPTT was 29 s (IQR 9.8) (p = 0.0001). The 30-day thromboembolic event rate was 6.1%. CONCLUSION: Further study is needed to characterize the hemostatic effects and thromboembolic risk of aPCC among patients with DOAC-associated bleeding or for attempted normalization of hemostasis prior to urgent surgery.

Impact of platelet transfusion on toxicity and mortality after hematopoietic progenitor cell transplantation.

BACKGROUND: Thrombocytopenia occurs commonly after hematopoietic progenitor cell transplantation (HPCT) and is associated with potential morbidity and mortality. Few studies have examined the impact of platelet (PLT) transfusion on clinical outcomes in HPCT while optimal PLT transfusion strategies after HSCT remain uncertain. STUDY DESIGN AND METHODS: A retrospective single-center cohort study was conducted on 522 patients undergoing HPCT between January 2002 and December 2007. Associations between PLT transfusion events and clinical characteristics with transplant-related outcomes were assessed using univariate and multivariate analysis. RESULTS: Mean number of PLT transfusion events before Day +60 posttransplant was 7.5 (95% confidence interval, 6.7-8.4) with greater number of events after allogeneic compared with autologous HPCT (p < 0.01). Univariate and multivariate analysis confirmed that the number of PLT transfusion events was associated with increased 100-day nonrelapse mortality (p < 0.01), posttransplant length of hospital stay (p < 0.01), need for intensive care unit admission (p < 0.01), and number of organs affected by severe toxicity (p < 0.01). CONCLUSION: HPCT-related toxicity and mortality are associated with increased PLT transfusion events. Alternative strategies to reduce PLT transfusions after HPCT may warrant future study.

Acute extravascular hemolytic transfusion reaction due to anti-Kpa antibody missed by electronic crossmatch.

BACKGROUND: Kpa antigen is a low incidence red blood cell antigen within the Kell system. Anti-Kpa alloantibody may be associated with acute and delayed hemolytic transfusion reactions. CASE STUDY: We report a case of a clinically significant acute extravascular hemolytic transfusion reaction mediated by previously unrecognized (and undetected) anti-Kpa alloantibody. This reaction occurred in a patient who met all criteria for electronic crossmatch, resulting in the transfusion of an incompatible red cell unit. RESULTS: Post-transfusion investigation showed the transfused red cell unit was crossmatch compatible at the immediate spin phase but was 3 + incompatible at the antiglobulin phase. No evidence of intravascular hemolysis was observed upon visual comparison of the pre- and post-transfusion peripheral blood plasma. Further testing showed the presence of anti-Kpa antibody. The clinical course of the patient included acute febrile and systemic reaction. CONCLUSION: Acute extravascular hemolytic transfusion reaction may occur due to undetected anti-Kpa alloantibody. Various strategies for crossmatching are discussed in the context of antibodies to low incidence antigens.

Is cytomegalovirus testing of blood products still needed for hematopoietic stem cell transplant recipients in the era of universal leukoreduction?

Hematopoietic stem cell transplantation (HSCT) recipients are a high-risk, immunocompromised group of patients who receive frequent transfusions after transplantation. Transfusion of cytomegalovirus (CMV)-negative blood products has long been the standard of care to prevent transfusion-transmitted CMV in this patient population. Leukoreduction of blood products before transfusion has been shown to significantly reduce the risk of transfusion-transmitted CMV. In the era of universal leukoreduction in Canada, the need for CMV testing of blood products remains unclear. We sought to identify whether there is a difference in transfusion-transmitted CMV viremia in patients receiving only leukoreduced versus CMV-negative and leukoreduced blood products in HSCT recipients. Patients who were CMV negative and received an allogeneic HSCT from a CMV-negative donor between October 1, 1999 and June 30, 2012 were included in the analysis. Transfusion data were collected from The Ottawa Hospital Blood Bank and Canadian Blood Services. CMV viremia was defined as PCR positivity. One hundred sixty-six patients were identified who met the inclusion criteria. Of these, 89 patients received an HSCT before January 2007, during the time when patients received leukoreduced and CMV-negative blood products. Seventy-seven patients received an HSCT after this time, receiving only leukoreduced blood products. The 2 groups did not differ in terms of age, gender, diagnosis, graft type, graft source, conditioning regimen, or ABO compatibility (P > .05). CMV viremia was detected in 3 patients who received CMV-negative leukoreduced blood products (3.37%) and in 1 patient who received only leukoreduced blood products (1.30%, P = .6244). Of the patients who developed CMV viremia, 2 developed suspected CMV disease. Both of these patients were transfused with CMV-negative blood products. Secondary outcomes, including total length of stay in hospital, admission to the intensive care unit, acute and chronic graft versus host disease, and 100-day nonrelapse mortality, did not differ between the groups. In the era of universal leukoreduction of blood products, this study demonstrates that testing for CMV-negative blood products is not needed for HSCT recipients.

Factors associated with the avoidance of red blood cell transfusion after hematopoietic stem cell transplantation.

BACKGROUND: Red blood cell (RBC) transfusion is required frequently for most patients after hematopoietic stem cell transplantation (HSCT). RBC transfusion, however, can be associated with adverse events including transfusion reactions, acquiring transmissible disease, and delayed recovery. Factors associated with avoidance of transfusion are not well documented. STUDY DESIGN AND METHODS: Data concerning RBC transfusions between Day 0 and Day +30 were analyzed for patients undergoing HSCT at a single Canadian transplant center between January 2002 and December 2007. RESULTS: Of 555 patients undergoing HSCT with complete RBC transfusion data, 59 patients (10.6%) did not require RBC transfusion in the first 30 days after HSCT. Univariate analysis showed no significant difference in age, graft source, donor type, or conditioning regimen between transfused and nontransfused patients. Factors that were significantly associated with avoidance of transfusion included male sex (p = 0.0013), diagnosis, specifically plasma cell dyscrasias (p < 0.0001), early-stage disease (p = 0.006), and higher baseline hemoglobin (Hb) at time of transplant (p < 0.0001). In multivariate analysis, higher pretransplant Hb, male sex, and early-stage disease remained significantly associated with avoidance of RBC transfusion. Pretransplant Hb correlated inversely with the number of RBC transfusions (r = -0.89). CONCLUSION: Increased pretransplant Hb, male sex, and early-stage disease are associated with avoidance of RBC transfusion after HSCT. Interventions aimed at improving pretransplant Hb levels require further study.

Anti-AnWj causing acute hemolytic transfusion reactions in a patient with aplastic anemia.

BACKGROUND: AnWj is a high-prevalence red blood cell (RBC) antigen in the ISBT 901 series. Only nine reports of anti-AnWj have been published since it was first documented in 1972; two of these cases involved transfusion reactions. We present a case of a patient with aplastic anemia who developed anti-AnWj with clinically significant hemolysis after transfusion of AnWj-positive RBCs. STUDY DESIGN AND METHODS: A 56-year-old woman with aplastic anemia developed a pan-reactive antibody with clinically significant hemolysis after transfusion of RBCs. Investigations included antibody identification by serologic methods at the national immunohematology reference laboratory and the in vitro monocyte-monolayer assay (MMA) to predict clinical significance. RESULTS: The antibody was identified as having specificity for the AnWj antigen. The posttransfusion MMA indicated that the antibody had complement-fixing capability highly likely to cause clinically significant acute hemolytic transfusion reactions. The patient required long-term transfusion support with AnWj-negative RBCs and Lu(a-b-) RBCs of the In(Lu) type which have reduced AnWj expression. Cross-Canada and international collaboration was required to obtain rare units for transfusion. CONCLUSION: A case of acute hemolytic transfusion reaction caused by anti-AnWj is reported in a patient with aplastic anemia requiring allogeneic stem cell transplantation. This is the second documented case of anti-AnWj to cause a hemolytic transfusion reaction. The case demonstrates the complexity of managing patients with rare antibodies and the importance of international collaboration in the management of these difficult cases.

Red blood cell storage lesions and related transfusion issues: a Canadian Blood Services research and development symposium.

For centuries, man has been trying to figure out how to revive sick and traumatized individuals using fluids of various types, even from animals. In the 17th century, it was determined that blood was the best fluid to use and, in the early 1900s, after the discovery of the ABO blood groups, human blood was found to provide significant benefit for patients with shock and/or anemia. In the 1950s and 1960s, various ways to obtain, process, and store human blood were developed. It soon became apparent that storage of human blood for transfusion was problematic because red cells, as they aged in vitro, underwent a multitude of physicochemical changes that greatly affected their shelf life, the so-called storage lesion. More recently, the question has arisen as to the potential detrimental effects of the storage lesion and suggestions that older blood may induce increased morbidity and even mortality despite its acceptable in vivo survival. To address this issue of the efficacy and safety of transfusion of aged stored blood, a number of controlled clinical trials have been instituted to determine if older blood is significantly detrimental compared with fresher blood in transfusion recipients.

Urgent replacement of a mechanical mitral prosthesis in an anticoagulated patient with Bombay red blood cell phenotype.

PURPOSE: Bombay red blood cell phenotype is an extremely rare blood type for which patients can receive only autologous or Bombay phenotype red blood cells. We report a case of urgent repeat sternotomy for replacement of a mechanical mitral prosthesis in a patient with Bombay phenotype anticoagulated with warfarin, to emphasize the transfusion challenges in such patients. CLINICAL FEATURES: A male of Indian descent presented to hospital with New York Heart Association IV symptoms. His medical history revealed previous mitral valve replacement with a mechanical prosthesis in 2005 and Bombay phenotype blood. Preoperative transthoracic echocardiography demonstrated thrombus obstruction of the mitral prosthesis despite anticoagulation with warfarin. Right ventricular systolic pressure was >100 mmHg with 3+ tricuspid regurgitation. The patient's condition was temporized with diuretics, bronchodilators, and bi-level positive airway pressure ventilation while transfusion medicine and cardiac surgery were consulted for urgent surgery. The patient received vitamin K and prothrombin complex concentrate prior to repeat sternotomy and successful mitral prosthesis replacement. After cardiopulmonary bypass, heparinization was corrected with protamine and followed by a second dose of prothrombin complex concentrate and recombinant activated factor VIIa. Postoperatively, the patient received four units of packed red blood cells, two autologous units and two units of Bombay specific red blood cells. Right ventricular pressures stabilized at 40 mmHg following surgery. The patient recovered following several days of inotropic support with milrinone, diuretics, and bronchodilators. CONCLUSION: Patients with Bombay phenotype red blood cells present as type O, but they are unable to receive red blood cells from any phenotype other than Bombay phenotype. They are able to receive all other blood products, including fresh frozen plasma, cryoprecipitate, platelets, prothrombin complex concentrate, and recombinant activated factor VIIa. Coordination between Canadian Blood Services, transfusion medicine, surgery, and anesthesia is important in managing these patients.

Hemolytic transfusion reactions after administration of intravenous immune (gamma) globulin: a case series analysis.

BACKGROUND: This case series summarizes our observations of hemolytic reactions after the administration of large amounts of intravenous immune (gamma) globulin (IVIG). STUDY DESIGN AND METHODS: Cases of hemolysis were identified by a decrease in hemoglobin not otherwise explained following IVIG administration. RESULTS: Sixteen cases were identified over a 2 1/2-year period at the Ottawa Hospital of approximately 1000 patients receiving IVIG (1.6%). Characteristics of these patients include a large dose of IVIG, female sex, non-O blood group, and underlying inflammatory state. CONCLUSIONS: Significant hemolysis may occur after the administration of large doses of IVIG. A two-step mechanism of hemolysis is proposed, sensitization by ABO isohemagglutinins followed by phagocytosis by activated macrophages. A simple protocol to facilitate the early detection of such cases is presented.