Current understanding of allergic transfusion reactions: incidence, pathogenesis, laboratory tests, prevention and treatment

Associations between transfusion reactions and thromboembolism development in blood-transfused patients: A retrospective cohort study

BACKGROUND

Blood transfusion (BT) may be associated with an increased risk of thromboembolism. The associations between transfusion reactions (TRs) during BTs and potential risk factors for the development of thromboembolism in patients underwent blood transfusion have not been analyzed. Therefore, this study aimed to compare risk factors associated with the development of venous thromboembolism (VTE) or pulmonary embolism (PE) between patients underwent blood transfusion with and without TRs.

STUDY DESIGNS AND METHODS

The retrospective study was conducted between April 1, 2017, and March 31, 2020, at a medical center in Taiwan. Blood-transfused patients were grouped into two cohorts as follows: those who experienced TRs and those who did not experience TRs. Both cohorts were subjected to follow-up until March 31, 2021. The endpoints for both groups were the occurrence of VTE or PE or the date of March 31, 2021. To investigate between-cohort risk differences, a Kaplan-Meier survival analysis and multiple Cox proportional hazard model was used.

RESULTS

A total of 10,759 patients underwent 59,385 transfusion procedures, with 703 patients in the TR group, and 10,056 patients in the non-TR group. The risk of VTE or PE was twice as high in the TR group than in the non-TR group (adjusted hazard ratio 2.53, 95% confidence interval 1.49-4.29, p = .001). Meanwhile, age, female sex, transfusion frequency increment, and being nondiabetic was associated with an increased risk of developing thromboembolism.

CONCLUSION

TRs are associated with increased long-term thromboembolism risk in patients underwent blood transfusion. It is imperative for clinicians to acknowledge this and maintain rigorous follow-up.

Reevaluation of the medical necessity of washed red blood cell transfusion in chronically transfused adults

BACKGROUND

Washing red blood cell (RBC) units mitigates severe allergic transfusion reactions. However, washing reduces the time to expiration and the effective dose. Automated washing is time- and labor-intensive. A shortage of cell processor tubing sets prompted review of medical necessity for washed RBC for patients previously thought to require washing.

STUDY DESIGN AND METHODS

A single-center, retrospective study investigated discontinuing wash RBC protocols in chronically transfused adults. In select patients with prior requirements for washing, due to a history of allergic transfusion reactions, trials of unwashed transfusions were performed. Patient demographic, clinical, laboratory, and transfusion data were compiled. The per-unit washing cost was the sum of the tubing set, saline, and technical labor costs.

RESULTS

Fifteen patients (median age 34 years interquartile range [IQR] 23-53 years, 46.7% female) were evaluated. These patients had been transfused with a median of 531 washed RBC units (IQR 244-1066) per patient over 12 years (IQR 5-18 years), most commonly for recurrent, non-severe allergic reactions. There were no transfusion reactions with unwashed RBCs aside from one patient with one episode of pruritus and another with recurrent pruritus, which was typical even with washed RBC. We decreased the mean number of washed RBC units per month by 72.9% (104 ± 10 vs. 28.2 ± 25.2; p < .0001) and saved US $100.25 per RBC unit.

CONCLUSION

Washing of RBCs may be safely reconsidered in chronically transfused patients without a history of anaphylaxis. Washing should be implemented judiciously due to potential lack of necessity and logistical/operational challenges.

Pilot study on the use of basophil activation tests and skin tests for the prevention of allergic transfusion reactions

Background and objectives

Management of severe allergic transfusion reactions (ATR) is challenging. In this study, we investigate the usefulness of skin tests and basophil activation tests (BAT) in chronically transfused patients for the prevention of future ATR.

Materials and methods

BAT and skin tests were carried with the supernatant of red blood cell (RBC) units for a sickle-cell disease patient under chronic exchange transfusion who has presented a severe ATR, in order to prevent potential future ATR. If the results for both BAT and skin tests were negative, the RBC units could be transfused to the patient. If either one of the results was positive, the tested RBC unit was discarded for the patient.

Results

192 RBC units were tested with both tests. The level of results concordance between the two tests was 95%. Out of the 169 negative units with both tests, 118 units were transfused to the patient for which he presented no ATR.

Conclusion

In our study, combining both BAT and skin tests was associated with a good negative predictive value since we were able to safely transfuse our patient. Further studies are still necessary to confirm this result but this pilot study indicates that skin tests and BAT might help prevent ATR. When BAT is not available, skin tests may also be useful in preventing ATR.

Self-anticoagulant sponge for whole blood auto-transfusion and its mechanism of coagulation factor inactivation

Clinical use of intraoperative auto-transfusion requires the removal of platelets and plasma proteins due to pump-based suction and water-soluble anticoagulant administration, which causes dilutional coagulopathy. Herein, we develop a carboxylated and sulfonated heparin-mimetic polymer-modified sponge with spontaneous blood adsorption and instantaneous anticoagulation. We find that intrinsic coagulation factors, especially XI, are inactivated by adsorption to the sponge surface, while inactivation of thrombin in the sponge-treated plasma effectively inhibits the common coagulation pathway. We show whole blood auto-transfusion in trauma-induced hemorrhage, benefiting from the multiple inhibitory effects of the sponge on coagulation enzymes and calcium depletion. We demonstrate that the transfusion of collected blood favors faster recovery of hemostasis compared to traditional heparinized blood in a rabbit model. Our work not only develops a safe and convenient approach for whole blood auto-transfusion, but also provides the mechanism of action of self-anticoagulant heparin-mimetic polymer-modified surfaces.

Retrospective study of canine blood xenotransfusion compared with type-matched feline blood allotransfusion to cats: indications, effectiveness, limitations and adverse effects

OBJECTIVES

Xenotransfusion is the transfusion of blood from one species to another. With varying availability of allogenic feline blood (AFB) and in emergency conditions, circumstances occur when canine blood is transfused to cats. This study aimed to characterise the indications, effectiveness, limitations, and acute and late transfusion-related adverse effects of canine blood xenotransfusion compared with matched AFB to anaemic cats, and their survival and longer-term outcome.

METHODS

This retrospective study (2013-2020) examined cats receiving canine blood xenotransfusions or AFB.

RESULTS

The study included 311 cats (xenotransfusion [X-group], n = 105; allotransfusion [A-group], n = 206). Xenotransfusion was more frequent among cats sustaining haemorrhage than in those with haemolysis (P <0.01) or hypoproliferative anaemia (P <0.001). Financial constraints were the most common reason to elect xenotransfusion (49%). The post-transfusion mean packed cell volume was higher (P <0.001) in the X-group (22%) compared with the A-group (18%), and also higher (P <0.001) at 48-96 h post-transfusion (23% vs 18%, respectively). Transfusion-related adverse effects (TRAEs) were more frequent (P = 0.001) in the X-group (37.1%) compared with the A-group (19.4%), as were delayed haemolytic transfusion reactions (85% vs 42.5%, respectively; P <0.001). Acute transfusion reactions (ATRs) were more frequent (P <0.001) in the A-group (60%) compared with the X-group (20%). TRAEs were unassociated with survival to discharge. The survival to discharge rate of the X-group (55%) was lower (P = 0.007) than in the A-group (73%), while post-discharge survival rates to 30 days of cats surviving to discharge were 90% and 88%, respectively (P = 0.85).

CONCLUSIONS AND RELEVANCE

Canine blood xenotransfusions to cats might save lives in emergency conditions when AFB is unavailable or blood typing is infeasible. The survival to discharge rate of the X-group was lower than that of the A-group. The longer-term survival rate of cats administered xenotransfusions and surviving to discharge from the hospital was good.

Blood Transfusion Components Inducing Severe Allergic Reactions: The First Case of Kounis Syndrome Induced by Platelet Transfusion

Kounis syndrome is a multisystem and multidisciplinary disease affecting the circulatory system that can be manifested as spasm and thrombosis. It can occur as allergic, hypersensitivity, anaphylactic, or anaphylactoid reactions associated with the release of inflammatory mediators from mast cells and from other interrelated and interacting inflammatory cells, including macrophages and lymphocytes. A platelet subset with high- and low-affinity IgE surface receptors is also involved in this process. Whereas the heart, and particularly the coronary arteries, constitute the primary targets of inflammatory mediators, the mesenteric, cerebral, and peripheral arteries are also vulnerable. Kounis syndrome is caused by a variety of factors, including drugs, foods, environmental exposure, clinical conditions, stent implantation, and vaccines. We report a unique case of a 60-year-old male with a past medical history of allergy to human albumin, alcoholic cirrhosis, and esophageal varices, who was admitted due to multiple episodes of hematemesis. Due to low hemoglobin levels, he was transfused with 3 units of red blood cells and fresh frozen plasma without any adverse reactions. On the third day of hospitalization, severe thrombocytopenia was observed and transfusion of platelets was initiated. Immediately following platelet infusion, the patient developed chest discomfort, skin signs of severe allergic reaction, and hemodynamic instability. The electrocardiogram revealed ST segment elevation in the inferior leads. Given the strong suspicion of Kounis syndrome/allergic coronary spasm, the patient was treated with anti-allergic treatment only, without any anti-platelet therapy. The clinical status of the patient gradually improved and the electrocardiographic changes reverted to normal. Based on these findings, Kounis hypersensitivity-associated acute coronary syndrome, specifically, type I Kounis syndrome, was diagnosed. Although platelet transfusion can be a life-saving therapy, each blood transfusion carries a substantial risk of adverse reactions. The aims of this report are to expand the existing knowledge of patient responses to blood transfusion and provide information on the incidence of various severe transfusion reactions to all blood components and especially to platelets. To the best of our knowledge, Kounis syndrome induced by platelet transfusionhas never been previously reported. Hypersensitivity to platelet external membrane glycoproteins in an atopic patient seems to be the possible etiology. Despite that Kounis syndrome remains an under-diagnosed clinical entity in everyday practice, it should always be considered in the differential diagnosis of acute coronary syndromes.

A Case of Fatal Clostridium perfringens Sepsis with Massive Hemolysis in the Setting of a Coincidental Platelet Transfusion

A 62-year-old woman with acute myeloid leukemia (AML) died of shock and massive hemolysis shortly after receiving two platelet transfusions at a routine clinic visit. Subsequent investigation into what was initially believed to be an acute hemolytic transfusion reaction secondary to platelet transfusions revealed that the patient died of Clostridium perfringens sepsis leading to massive hemolysis. Further investigation ruled out bacterially-contaminated platelets since a patient blood sample from 2 days prior had Clostridium species. The unusual findings and management considerations for this oncology patient are reviewed and compared with previously reported cases of C. perfringens transfusion-transmitted infections. Oncology patients may be especially susceptible to unusual presentations involving unusual pathogens.

Biological investigations of transfusion reactions: contribution of symptom-based decisional algorithms

OBJECTIVES

While transfusion is a common and safe therapeutic procedure in health care facilities, transfusion reactions can occur, whether acute or delayed, mild or life-threatening. In face of these reactions, the biological analysis laboratory plays a central role in their diagnosis. The objective of this article is to develop decisional algorithms for laboratory tests to be performed according to the clinical symptoms developed by the patient during or after transfusion.

METHODS

Based on the information collected by reviewing the literature and the procedures used in our hospital, we then developed biological investigation algorithms according to the symptoms presented by the patient, rather than the presumed reaction.

RESULTS AND CONCLUSION

We have developed symptom-based algorithms for acute transfusion reactions management that streamline laboratory testing and simplify the differential diagnosis.

Transfusion-Related Acute Lung Injury (TRALI) in Postoperative Anesthesia Care Unit (PACU) After One Unit of Platelets: A Case Report

Transfusion-related acute lung injury (TRALI) following transfusion of all plasma-containing blood products is a rare but serious syndrome characterized by the acute onset of non-cardiogenic pulmonary edema with severe hypoxemia with or without symptoms of hypotension, pinkish frothy secretions, fever, and cyanosis. In this report, we present a case of a 66-year-old female with a medical history significant for hypertension, hyperlipidemia, hepatitis C, liver cirrhosis, tobacco use disorder, metastatic spindle cell carcinoma of the lung status post chemotherapy who developed TRALI after administration of one unit of platelets. Although a rare occurrence, there can be a considerable risk of TRALI following transfusion of all plasma-containing blood products and there is great importance in considering each patient’s risk factors for TRALI development prior to blood product administration.

Adverse transfusion reactions and what we can do

INTRODUCTION

Transfusions of blood and blood components have inherent risks and the ensuing adverse reactions. It is very important to understand the adverse reactions of blood transfusion comprehensively for ensuring the safety of any future transfusions.

AREAS COVERED

According to the time of onset, adverse reactions of blood transfusion are divided into immediate and delayed transfusion reactions. In acute transfusion reactions, timely identification and immediate cessation of transfusion is critical. Vigilance is required to distinguish delayed responses or reactions that present non-specific signs and symptoms. In this review, we present the progress of mechanism, clinical characteristics and management of commonly encountered transfusion reactions.

EXPERT OPINION

The incidence of many transfusion-related adverse events is decreasing, but threats to transfusion safety are always emerging. It is particularly important for clinicians and blood transfusion staff to recognize the causes, symptoms and treatment methods of adverse blood transfusion reactions to improve the safety. In the future, at-risk patients will be better identified and can benefit from more closely matched blood components.

Blood Transfusion Reactions-A Comprehensive Review of the Literature including a Swiss Perspective

Blood transfusions have been the cornerstone of life support since the introduction of the ABO classification in the 20th century. The physiologic goal is to restore adequate tissue oxygenation when the demand exceeds the offer. Although it can be a life-saving therapy, blood transfusions can lead to serious adverse effects, and it is essential that physicians remain up to date with the current literature and are aware of the pathophysiology, initial management and risks of each type of transfusion reaction. We aim to provide a structured overview of the pathophysiology, clinical presentation, diagnostic approach and management of acute transfusion reactions based on the literature available in 2022. The numbers of blood transfusions, transfusion reactions and the reporting rate of transfusion reactions differ between countries in Europe. The most frequent transfusion reactions in 2020 were alloimmunizations, febrile non-hemolytic transfusion reactions and allergic transfusion reactions. Transfusion-related acute lung injury, transfusion-associated circulatory overload and septic transfusion reactions were less frequent. Furthermore, the COVID-19 pandemic has challenged the healthcare system with decreasing blood donations and blood supplies, as well as rising concerns within the medical community but also in patients about blood safety and transfusion reactions in COVID-19 patients. The best way to prevent transfusion reactions is to avoid unnecessary blood transfusions and maintain a transfusion-restrictive strategy. Any symptom occurring within 24 h of a blood transfusion should be considered a transfusion reaction and referred to the hemovigilance reporting system. The initial management of blood transfusion reactions requires early identification, immediate interruption of the transfusion, early consultation of the hematologic and ICU departments and fluid resuscitation.

Development of the Chinese Haemovigilance Network and reporting of adverse transfusion reactions from 2018 to 2020

BACKGROUND AND OBJECTIVES

To advance blood transfusion safety, the Chinese Haemovigilance Network (CHN) was put into operation in 2018. This report describes the development of the CHN and evaluates its role by analysing reported adverse transfusion reactions (ATRs) from 2018 to 2020.

MATERIALS AND METHODS

All data in this study were obtained from the CHN online reporting platform. A timeline of CHN development is presented, and the activities of CHN-enrolled facilities are analysed by year. The reported ATRs were analysed in detail for ATR types, blood components involved and adherence to case definition, severity and imputability criteria. Incidence rates were calculated and compared with international examples.

RESULTS

During 2018-2020, a total of 3061 ATRs were reported through the CHN online reporting system. The rate of reported ATRs in all facilities and the 10 highest reporting facilities was 0.7‰ and 1.8‰, respectively. When analysed by year, the incidence rate showed an increasing trend from 2018 to 2020. Allergic (68.2%) and febrile non-haemolytic transfusion reaction (27.1%) were the most common. The vast majority of ATRs (92.0%) were not serious, but serious cases of transfusion-associated circulatory overload, transfusion-associated dyspnoea and hypotensive reaction were common. Most (86.0%) of reported cases were definitely or probably associated with transfusion.

CONCLUSION

Under-reporting of ATRs occurs in many Chinese hospitals, but the establishment of CHN has increased ATR recognition and management. More effort will be needed in the future to detect transfusion problems and improve transfusion practice in China.

Incidence of intraoperative anaphylaxis caused by blood products: a 12-year single-center, retrospective study

PURPOSE

Intraoperative anaphylaxis caused by blood products is uncommon, but it is unclear whether the rarity of this reaction is attributable to the difficulty of diagnosis, underreporting, or both. We investigated the incidence of intraoperative transfusion anaphylaxis and its reporting to the hemovigilance system.

METHODS

We retrospectively reviewed cases wherein general anesthesia was used at a single hospital during a 12-year period. Cases of intraoperative anaphylaxis were extracted using an electronic search strategy and determined using the recently developed grading and clinical scoring system. The causative blood products were determined by the onset duration based on literature regarding intraoperative transfusion anaphylaxis cases.

RESULTS

Among the 62,146 general anesthesia cases, 22 cases of intraoperative anaphylaxis were identified, and 11 of the 22 cases received transfusions before the onset of anaphylaxis. Intraoperative transfusion anaphylaxis was defined as occurring within 30 min of transfusion. Finally, nine cases of intraoperative transfusion anaphylaxis were analyzed. The overall incidence of intraoperative transfusion anaphylaxis was 1/3,994, with the highest incidence noted for fresh frozen plasma (1/2146; 95% confidence interval [CI] 1/6610-1/920), platelet concentrate (1/2348; 95% CI 1/92,742-1/422), and red blood cells (1/22,867; 95% CI 1/903,199-1/4,105). No evidence indicated that these cases were reported to the Japanese hemovigilance system, although all intraoperative transfusion anaphylaxis cases were diagnosed by anesthesiologists.

CONCLUSION

The incidence of intraoperative anaphylaxis caused by blood products was higher than that reported and may be underreported to the Japanese hemovigilance system. Further research, particularly multicenter studies, is needed to confirm our results.

Rationalised premedication practice for blood product transfusions: A single-centre quality initiative

AIM

Blood and platelets are scarce resources that are an essential part of the supportive care for paediatric cancer patients. There are many inherent risks involved with transfusions including acute transfusion reactions (ATRs). Following an initial ATR, prophylactic medications are commonly given prior to subsequent transfusions. However, there are risks with medication administration as well as negative implications for the health system. Our aim was to prevent the automatic prescribing of premedications prior to blood and platelet transfusions for ATRs. We hypothesised this would not increase the risk of harm.

METHODS

Our intervention was to eliminate automatic prescribing of intravenous corticosteroids and intravenous promethazine prior to a transfusion. This was approached through a behaviour change model and the implementation of recommended prescribing guidelines. Three Plan Do Study Act (PDSA) cycles refined the guidelines to align with clinicians' needs and build support through co-design. Data gathered on individual patients receiving transfusions and reaction rates during the trial were compared to international data.

RESULTS

A total of 100 patients received a transfusion during the trial. Eleven patients either had a previous reaction or experienced their first reaction during this time. All patients followed the guidelines and had either no premedication or an oral antihistamine premedication. There were no breakthrough reactions using oral antihistamines. The overall reaction rate was 1.33%, which aligns with the reported data on ATRs internationally.

CONCLUSION

A restricted prescribing approach to pharmaceutical cover prior to blood and platelet transfusions can be implemented effectively in a paediatric cancer population, without an increase in the risk of harm to the patients.

Dual preparation of plasma and platelet concentrates in platelet additive solution from platelet concentrates in plasma using a novel filtration system

BACKGROUND AND OBJECTIVES

Platelet concentrates suspended in a platelet additive solution (PAS-PC) are associated with a reduction in allergic response and are suitable for preparing pathogen-inactivated PC. We aimed to develop an efficient platform for the dual preparation of PAS-PC and platelet-poor plasma.

MATERIALS AND METHODS

PAS-PC was prepared in six steps by using a hollow-fibre system based on cross-flow filtration: priming, loading PC, loading PAS, collection of filtered liquid (flow-through) and collection of platelets by washing with PAS followed by washing with air. In this study, the efficacy of platelet and plasma protein recovery and characteristics of recovered PAS-PC and flow-through plasma were analysed in detail.

RESULTS

Recoveries of platelet in PAS-PC and plasma protein in the flow-through were 95.4% ± 3.7% and 61.6% ± 5.0%, respectively. The residual plasma protein in PAS-PC was 34.1% ± 2.8%. Although the expression level of CD62P, a platelet activation marker, in recovered platelets was approximately 1.2-fold of that in original platelets, swirling patterns were well retained, and aggregation in PAS-PC was not visible. Agonist-induced aggregabilities, platelet morphology and hypotonic shock recovery were conserved. The patterns of plasma protein and lipoprotein in the flow-through were comparable with those in the original PCs. The multimeric pattern analysis of VWF remained unaltered.

CONCLUSION

We propose a highly efficient preparation system that enables the simultaneous production of PAS-PC and platelet-poor plasma. It also achieves a high recovery of functionally well-retained platelets with very low activation.

Frequency and clinical characteristics of allergic transfusion reactions in children

Allergic transfusion reactions (ATRs)are a common form of acute transfusion reaction. It was aimed to determine the clinical characteristics and frequency of ATRs in children. This study included children who were transfused with red cell concentrate (RCC), fresh-frozen plasma (FFP), platelet concentrates(PC), apheresis granulocyte, and cryoprecipitate.The patients' sociodemographic characteristics, the blood product that caused the reaction, the type and timing of the reaction, the patient's age at time of reaction and their diagnosis, follow-up period, and clinical data were recorded. A total of 89703 bags of blood products were transfused to 4193 children.Two hundred eleven acute transfusion-related reactions occurred in 157 (3.74%) patients.Of these, 125 reactions (59%) were allergic. ATR occurred in 125 of 89703 infusions (0.14%).The median age of patients was 9.99 years (IQR:4.67-14.38) and ATRs occurred at a median of 30 minutes into the transfusion. Eighteen (18%) of the patients also had a history of drug reaction.When the blood products that caused ATRs were examined, 43(34.5%) occurred with apheresis and single-donor PC, 37(29.6%) with FFP, 32 (25.6%) with RCC, 10(8%) with pooled PC, 2(1.6%) with cryoprecipitate, 1(0.8%) with apheresis granulocyte.Ninety-nine(79%) of the reactions were minor allergic reactions and 26(21%) were anaphylaxis.Compared to minor allergic reactions, the proportion of PCs was statistically higher in anaphylaxis(p=0.02). Patients receiving PC should be monitored more carefully during the first half hour of transfusion. In addition, approximately one-fifth of the patients who developed ATR also had a history of drug reaction. Patients with previous reactions to drugs may be more likely to have ATR.

Transfusion-related adverse reactions: Data from the National Healthcare Safety Network Hemovigilance Module - United States, 2013-2018

BACKGROUND

Despite current blood safety measures, transfusion recipients can experience transfusion-related adverse reactions. Monitoring these reactions can aid in understanding the effectiveness of current transfusion safety measures. Data from the National Healthcare Safety Network Hemovigilance Module were used to quantify adverse reaction risk.

METHODS

Facilities reporting at least one month of transfused blood components and transfusion-related adverse reactions during January 2013-December 2018 were included. Adverse reaction rates (number per 100,000 components transfused) were calculated for transfused components stratified by component type, collection, and modification methods.

RESULTS

During 2013-2018, 201 facilities reported 18,308 transfusion-related adverse reactions among 8.34 million blood components transfused (220/100,000). Adverse reactions were higher among apheresis (486/100,000) and pathogen-reduced platelets (579/100,000) than apheresis red blood cells (197/100,000). Allergic reactions (41%) were most common. There were 23 fatalities and 9% of all adverse reactions were serious (severe, life-threatening, or fatal). Reactions involving pulmonary complications (transfusion-associated circulatory overload, transfusion-related acute lung injury and transfusion-associated dyspnea) accounted for 35% of serious reactions but 65% of fatalities. Most (76%) of the 37 transfusion-transmitted infections were serious; none involved pathogen-reduced components.

CONCLUSIONS

One in 455 blood components transfused was associated with an adverse reaction although the risk of serious reactions (1 in 6224) or transfusion-transmitted infections (1 in 225,440) was lower. Some serious reactions identified were preventable, suggesting additional safety measures may be beneficial. Higher reaction rates identified among pathogen-reduced platelets require further study. These findings highlight the importance of monitoring reactions through national hemovigilance to inform current safety measures and the need for strategies to increase healthcare facility participation.

Preventing adverse reactions in pediatric transfusions using washed platelet concentrate

Blood transfusion is an important form of supportive care in children; however, transfusion-associated adverse reactions (TARs) are a problem. As with adults, allergic transfusion reactions (ATRs) and febrile non-hemolytic transfusion reactions (FNHTRs) are major TARs, and the frequency of ATRs caused by platelet concentrate (PC) tends to be particularly high. The plasma component of the blood product is thought to be a major factor in the onset of TARs such as ATR and FNHTR. By contrast, in children, age, underlying disease, and number of blood transfusions may be relevant patient-related factors. Although acetaminophen or diphenhydramine may be used prophylactically to prevent TARs, there is no clear evidence of their effectiveness. Volume-reduced PC is used to prevent TARs; however, it may be difficult to maintain the quality of platelets. Plasma-replaced PC stored with platelet additive solution raises the concern that TARs cannot be completely prevented by residual plasma. Washed PC removes most of the plasma, so it can effectively prevent ATR and FNHTR. The recent development of platelet additive solution [M-sol, bicarbonate Ringer's solution supplemented with acid-citrate-dextrose formula A (BRS-A)] in Japan has enabled the maintenance of the quality of platelets for long periods. The clinical use of washed PC in Japan has therefore progressed. Washed PC with M-sol or BRS-A for pediatric patients can effectively prevent TARs without diminishing the transfusion effect. The supply of washed PC has begun from the Japanese Red Cross Society, and it has become possible to use washed PC at all medical institutions in Japan.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS). Part 1: Definitions and clinical signs

OBJECTIVE

To use a systematic, evidence-based consensus process to develop definitions for transfusion reactions in dogs and cats.

DESIGN

Evidence evaluation of the literature was carried out for identified transfusion reaction types in dogs and cats. Reaction definitions were generated based on synthesis of human and veterinary literature. Consensus on the definitions was achieved through Delphi-style surveys. Draft recommendations were made available through industry specialty listservs and comments were incorporated.

RESULTS

Definitions with imputability criteria were developed for 14 types of transfusion reactions.

CONCLUSIONS

The evidence review and consensus process resulted in definitions that can be used to facilitate future veterinary transfusion reaction research.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) transfusion reaction small animal consensus statement (TRACS). Part 3: Diagnosis and treatment

OBJECTIVE

To systematically review available evidence to develop guidelines for diagnosis and treatment of transfusion-associated reactions in dogs and cats.

DESIGN

Standardized and systemic evaluation of the literature (identified through Medline via PubMed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. The available evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. The evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines, diagnostic, and treatment algorithms were generated based on the evaluation of the evidence. Consensus on the final guidelines was achieved through Delphi-style surveys. Draft recommendations were disseminated through veterinary specialty listservs for review and comments, which were evaluated and integrated prior to final publication.

RESULTS

Medline via PubMed and Google Scholar databases were searched. There were 14 Population Intervention Comparison Outcome questions identified and corresponding worksheets were developed focusing on the diagnosis and treatment of transfusion-associated reactions in dogs and cats. Fourteen guidelines and four algorithms were developed with a high degree of consensus.

CONCLUSIONS

This systematic evidence evaluation process yielded recommended diagnostic and treatment algorithms for use in practice. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Preoperative autologous blood donation and transfusion in dogs undergoing elective surgical oncology procedures with high risk of hemorrhage

OBJECTIVE

To describe preoperative autologous blood donation (PABD) and transfusion in dogs undergoing elective surgical oncology procedures with a high risk of intraoperative hemorrhage.

STUDY DESIGN

Prospective study.

ANIMALS

Twelve dogs.

METHODS

Dogs undergoing surgical oncology procedures associated with a high risk of hemorrhage were enrolled. Blood was collected a minimum of 6 days before surgery and separated into fresh frozen plasma (FFP) and packed red blood cells (pRBC). Dogs received FFP at the start of surgery and pRBC intraoperatively when hemorrhage ensued. The mean packed cell volume/total solids (PCV/TS) were calculated on the day of PABD preoperatively, immediately postoperatively, and 24 hours after transfusion. The dogs were monitored for transfusion-related adverse reactions, including hyperthermia, hypotension, tachycardia, bradycardia, pale mucous membranes, prolonged capillary refill time, or tachypnea/dyspnea.

RESULTS

Dogs enrolled in the study underwent mandibulectomy, maxillectomy, chest wall resection, and liver lobectomy. Ten of the 12 dogs that underwent PABD received autologous transfusion at first signs of hemorrhage intraoperatively. Iatrogenic anemia was noted in two dogs (PCV 30% and 31%). The mean PCV/TS levels on the day of blood collection, preoperatively, immediately postoperatively (after transfusion), and 24 hours posttransfusion were 45.1%/7.1 g/dL, 42.2%/6.73 g/dL, 33.2%/5.42 g/dL, and 36.5%/5.65 g/dL, respectively. No dog developed transfusion-related complications.

CONCLUSION

Preoperative autologous blood donation was well tolerated and led to uneventful autologous transfusion in 10 of 12 dogs.

CLINICAL SIGNIFICANCE

Preoperative autologous blood donation and autologous transfusion are feasible for dogs undergoing elective surgical procedures with a high risk of hemorrhage.

Contribution of donor- and recipient-associated factors to allergic transfusion reactions to platelets

BACKGROUND

Pediatric hematology-oncology patients require frequent platelet transfusions to manage chemotherapy-induced thrombocytopenia, and allergic transfusion reactions (ATRs) are common. Risk for platelet-associated ATRs can result from recipient- or donor-specific factors.

STUDY DESIGN AND METHODS

We report a rare case in which an individual platelet donor caused repeated ATRs in multiple recipients. This observation led us to conduct a retrospective study at a pediatric hematology-oncology center to identify donor- and recipient-associated risk factors for ATRs.

RESULTS

Single-donor platelets from an individual donor precipitated ATRs in 78.6% (n = 11/14) of recipients and 66.7% (n = 12/18) of platelet transfusions. We found in a cohort of pediatric hematology-oncology patients that 12.6% of recipients and 1.0% of platelet transfusions were associated with ATRs. Recipients who were aged 4 to 18 years, male, and those with central nervous system or solid tumors and with a history of ATRs to platelets were more likely to experience ATRs. Donor-associated risk factors were not identified, and we did not implicate additional donors in our single-center cohort with a frequency of ATRs comparable to the index donor. Based on our findings, we developed a novel statistical model to identify recipients and donors prone to experiencing or mediating ATRs.

CONCLUSIONS

Both donors and recipients contribute to ATRs. Identification of high-risk donors and recipients for further scrutiny and potential interventions can improve the safety of platelet transfusions.

Two Episodes of Transfusion-related Acute Lung Injury (TRALI) Occurring within a Short Period

Transfusion-related acute lung injury (TRALI) is a non-hemolytic adverse reaction that occurs ≤6 hours after receiving a transfusion. A 72-year-old man with leukemia developed severe hypoxemia after platelet transfusions on two occasions within a 4-day period. During the first episode, the transfused platelet preparation was positive for anti-human-leukocyte antigen antibodies. The pathogenesis of TRALI includes an antibody-mediated mechanism and a non-antibody-mediated mechanism, in which various factors combine to activate pulmonary neutrophils. In our case, it is considered that the patient's neutrophils reached the activation threshold for the development of TRALI after the accumulation of various factors besides anti-leukocyte antibodies.

Incidence and risk factors of transfusion reactions in postpartum blood transfusions

Postpartum hemorrhages with blood transfusions are increasing in many high-resource countries. Currently, up to 3% of all women receive blood transfusion postpartum. Most blood transfusions are safe and, in many cases, are lifesaving, but there are significant concerns about adverse reactions. Pregnancy is associated with higher levels of leukocyte antibodies and has a modulating effect on the immune system. Our objective was to investigate whether blood transfusions postpartum are accompanied by an increased risk for transfusion reactions (TRs) compared with transfusions given to nonpregnant women. We included all women who gave birth in Stockholm County, Sweden between 1990 and 2011. Data from the Swedish National Birth Registry were linked to the Stockholm Transfusion Database and included information on blood components administered and whether a TR occurred in women who received blood transfusions postpartum. Background controls were nonpregnant women who received blood transfusions during the study period. The study cohort consisted of 517 854 women. Of these, 12 183 (2.4%) received a blood transfusion. We identified 96 events involving a TR postpartum, giving a prevalence of 79 per 10 000 compared with 40 per 10 000 among nonpregnant women (odds ratio, 2.0; 95% confidence interval, 1.6-2.5). Preeclampsia was the single most important risk factor for TRs (odds ratio, 2.1; 95% confidence interval, 1.7-2.6). We conclude that special care should be taken when women with preeclampsia are considered for blood transfusion postpartum, because our findings indicate that pregnancy is associated with an increased risk for TRs.

Platelet concentrate and type II IL-1 receptor are risk factors for allergic transfusion reactions in children

PURPOSE

Allergic transfusion reactions (ATRs) are immunological reactions after transfusion. Interleukin-1 (IL-1) is a critical regulator for human diseases. We performed this study to investigate the association of type II IL-1 decoy receptor (IL1R2) expression with ATRs in children.

METHODS

Children received blood transfusions between January and December 2019 were included. The age, sex, number and type of blood transfusion, allergic history, and medical history were collected and statistically analyzed. The blood samples were collected from children with and without ATRs for detecting the relative expression IL1R2 mRNA. Logistics regression analysis was performed to identify the risk factors for ATRs in children. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the predictive performance of risk factors.

RESULTS

Totally, 28,840 transfusions in 20,230 children, with 236 ATRs (0.82%) in 117 patients (0.58%) were included. ATRs were common in children at the hematology-oncology department, in children received higher number of blood transfusions, and older children. Platelet concentrate induced a higher incidence of ATRs (3.31%) than red cell concentrate (0.22%, p < 0.0001). After the transfusion, IL1R2 mRNA level was higher in the blood samples in children with ATRs than those without ATRs (p < 0.0001). Logistics regression analysis indicated that platelet concentrate (95% CI 3.555, 293.782) and IL1R2 expression (95% CI 1.171 × 10², 1.494 × 10⁴) were independent risk factors for ATRs in children. IL1R2 expression had high performance in predicting ATRs (AUC = 0.998, 100% sensitivity and 98.85% specificity).

CONCLUSION

High IL1R2 expression level in children who received blood transfusions may predict the morbidity of ATR.

Exploration of risk factors for non-survival and for transfusion-associated complications in cats receiving red cell transfusions: 450 cases (2009 to 2017)

OBJECTIVES

To describe red blood cell transfusion practices and short-term outcomes in anaemic cats. To determine clinical variables associated with non-survival and transfusion-related complications.

MATERIAL AND METHODS

In this retrospective study, blood bank records from the Ontario Veterinary College Health Science Centre (OVC-HSC) were reviewed to identify cats that received packed red blood cells or whole blood from 2009 to 2017. We extracted cause of anaemia, history of previous transfusion, pre- and post-transfusion packed cell volume, pre-transfusion compatibility testing, volume and dose of blood product, age of red blood cell unit, transfusion-associated complications and patient survival.

RESULTS

A total of 450 transfusion events were recorded in 267 cats. Blood loss was the most common indication for blood transfusion (44.9%), followed by ineffective erythropoiesis (37.5%) and red blood cell destruction (22.5%). Transfusion-associated complications occurred in 10.2% events and there was a 20.2% mortality after transfusion. Mean increase in packed cell volume 24-hours after transfusion was greater in cats undergoing major cross-match testing before transfusion (7.2%) versus those that did not (4.0%). Non-survival was associated with higher packed cell volume before transfusion, low patient body temperature before transfusion, anaemia due to blood loss and number of transfusions administered. Older age of transfused blood units was associated with non-survival and transfusion-related complications.

CLINICAL IMPORTANCE

This study was observational and so our analyses were exploratory, but suggest that major cross-match before transfusion tended to have greater transfusion efficacy and transfusion of older blood products might have detrimental effects on survival.

Proportion of Acute Transfusion Reaction and Associated Factors Among Adult Transfused Patients at Felege Hiwot Compressive Referral Hospital, Bahir Dar, Northwest Ethiopia: A Cross-Sectional Study

Introduction

Acute transfusion reactions are adverse events occurring within 24 hrs of transfusion and cause simple-to-severe complications. They may vary with the blood component transfused and recipient factors. In Ethiopia, there is a limited evidence about the incidence and associated factors of transfusion reactions.

Objective

To determine the proportion of acute transfusion reactions and associated factors among adult transfused patients.

Methods

A total of 384 study participants were included in the study. Structured questionnaires were used for socio-demographic and past medical history data collection. Vital signs were measured as a baseline for every study participants and monitored and followed for 24 hrs. Laboratory tests like complete blood count, direct anti-human globulin test and urine hemoglobin were done as a baseline for suspected patients. Cross-match, blood grouping, and blood culture for patients and donors sample were also done for suspected patients. Descriptive statistics, bivariable and multivariable binary logistic regression were analyzed using SPSS version 20. P-value of <0.05 in the multivariable model was considered as statistically significant.

Results

Acute transfusion reactions were observed in 5.2% of patients. Of total cases of acute transfusion reaction, the majority developed allergic reactions (65%) and febrile non-hemolytic transfusion reaction (30%). It was significantly associated with transfusion history (AOR=3.4; 95% CI: 1.2–9.7), abortion history (AOR=5.0; 95% CI: 1.5–16.4), longer blood storage time (AOR=5.1; 95% CI: 1.7–15.2) and receiving three or more unit of blood (AOR= 4.1; 95% CI: 1.5–11.2).

Conclusion

Acute transfusion reactions were observed in 5.2% of patients (allergic reactions (65%), febrile non-hemolytic transfusion reaction (30%) and alloimmunization (5%)). Patients with a history of transfusion, abortion, transfused with blood stored ≥14 days and multi-transfused patients should be closely monitored.

Successful prevention of severe allergic transfusion reactions with omalizumab

BACKGROUND

Allergic transfusion reactions (ATRs) are a common adverse reaction to transfusion therapy and can be potentially fatal. Washing blood products is the most effective strategy for preventing ATRs; however, washed products, especially platelets, are not available at many blood centers.

STUDY DESIGN AND METHODS

A 29-year-old female patient with an advanced myelodysplastic/myeloproliferative neoplasm, unclassifiable, developed severe ATRs after four platelet transfusions in a week. She showed no response to premedication with histamines and steroids and still had severe ATRs with the next three platelet transfusions. A laboratory workup revealed that her IgA level was slightly decreased, while her haptoglobin level was normal. Anti-IgA testing was not available. The patient decided to undergo allogeneic peripheral blood stem cell (PBSC) transplantation. As the onset of symptoms ATR, which were similar to Type 1 hypersensitivity reactions mediated by IgE antibodies, occurred immediately after transfusion and omalizumab is a humanized monoclonal anti-IgE, we elected to offer off-label use of omalizumab before administering the conditioning regimen.

RESULTS

Omalizumab was injected subcutaneously at a dose of 150 mg. Surprisingly, transfusion reactions fully resolved within 24 hours. No serious side effects were noticed. Another 150 mg of omalizumab was administered 1 day before PBSC infusion. The patient remained asymptomatic without any signs of ATRs throughout the whole period of transplantation. Seven months after transplantation, the patient was in complete remission without overt complications.

CONCLUSION

This case suggests that omalizumab is a promising new alternative treatment for the prevention of severe ATRs.

Transfusion-Associated Acute Lung Injury following Donor Granulocyte Transfusion in Two Pediatric Patients

Transfusion-associated acute lung injury (TRALI) is one of the complications seen due to transfusion. Hypoxemia and bilateral pulmonary infiltration in posteroanterior chest roentgenogram is seen in all cases during transfusion or within the first 6 hours; fever, hypotension, and pink frothy bleeding from endotracheal tube may also be seen. It can be seen following the administration of any blood product. The management strategies for TRALI include withholding the transfusion, positive pressure breathing support, and diuretics. There are few reported cases of TRALI occurring following donor granulocyte transfusion (DGT). In this article, we discuss two cases of TRALI following DGT transfusion.

Investigation of factors associated with allergic transfusion reaction due to platelet transfusion and the efficacy of platelets resuspended in BRS-A in adult patients

BACKGROUND

Although allergic transfusion reactions (ATRs) resulting from platelet concentrate (PC) are a common adverse reaction, the mechanism underlying ATRs has not been fully elucidated. Plasma-replaced PC suspended in bicarbonate Ringer's solution and anticoagulant citrate dextrose solution A (RPC-B) is effective for preventing ATRs in children in Japan; however, there is not enough evidence in adult populations.

STUDY DESIGN AND METHODS

We conducted a retrospective analysis focused on factors associated with ATRs developing from PC transfusions in adult patients in a single institution between 2015 and 2018. The clinical efficacy of RPC-B for adult patients was also analyzed.

RESULTS

In total, 4,677 untreated regular PC products in plasma were transfused into 914 patients. ATRs developed in 65 patients (7.1%) treated with 92 PC products (2.0%). Multivariate analysis revealed that patients who were elderly, diagnosed with a non-hematological disease, and who received a transfusion of fresh-frozen plasma and red blood cell concentrate products together with PC products had lower frequencies of ATRs. Although 40 patients received 490 RPC-B transfusions, six ATRs (1.2%) were confirmed in five patients (12.5%). The ATR frequency was not significantly lower in the analysis of all patients; however, ATRs in patients with hematological diseases were lower in terms of both the patient and product numbers. Corrected count increments (24 hr) were also within an acceptable range in patients with hematological diseases.

CONCLUSION

Several patient-specific factors may be associated with the development of ATRs from PC transfusion. Because RPC-B appears to efficiently prevent ATRs, even in adult patients, safe and efficient transfusions may be performed by using RPC-B preferentially depending on the patient's risk factors.

Blood product and laboratory resource wastage in non-severe allergic transfusion reactions: an opportunity for improvement

OBJECTIVE

To evaluate the degree of blood product and technical resources wasted as a result of allergic transfusion reactions.

BACKGROUND

Allergic reactions are common, and most are non-severe with rash, urticaria, or pruritus. Management includes treatment of symptoms and completion of transfusion. A quality review demonstrated that 30% of transfusion reaction work-ups at our institution were allergic. This raised the concern of product wastage and unnecessary utilisation of laboratory resources.

METHODS

We conducted a retrospective study of allergic reactions, including type of product implicated, volume of products transfused and discarded, the severity of reaction, the use of medications, the incidence of symptom resolution and the rate of repeat transfusion after the allergic event.

RESULTS

Of 179 allergic reactions, non-severe reactions were reported in 75%. Non-severe reactions were associated with red blood cell, whereas most severe reactions were associated with platelets. Few cases had premedication; however, 83% of reactions were treated once symptoms developed, and 96% resolved. Of transfusions, 61% were stopped because of symptoms before the transfusion was completed. Of patients with non-severe reactions and transfusions that were not completed, 36% were transfused again within 48 h, representing 16% of all allergic reactions.

CONCLUSION

Allergic reactions resulted in partial transfusion of the prescribed product in just over half of the cases reviewed. Most of these reactions were non-severe, resolved with treatment and could have been completed, thus representing wastage of both blood products and the expense of the reaction evaluation. Educational efforts to eliminate/minimise this waste are in development.

Incidence and Analysis of 7 Years Adverse Transfusion Reaction: A Retrospective Analysis

Safe blood transfusion is the primary need of all the health care delivery system. Though with the advances of transfusion medicine, the incidences of transfusion risk is gradually reduced, but the adverse transfusion reaction (ATR) of non hemolytic type still prevails. The purpose of this study was to estimate the incidence and pattern of transfusion-related adverse events at our centre. The present retrospective observational study was conducted in the Department of Transfusion Medicine from April 2011 to April 2018, at a multi-organ transplant centre in South India. All the Adverse transfusion reactions were investigated in detail in the blood bank for the clerical errors, immunohematology workup and classified according to their nature with imputability assessment. A total of 140 ATR were reported out of 100,569 blood components distributed during the study period. After the analysis and workup of the reported reactions, majority of the reactions were observed in males (71%, n = 99). Most common symptom presented was Itching/Rashes in 43.6% (n = 61) ATR. Allergic reactions (51.4%, n = 72), were the most commonly encountered ATR followed by FNHTR (25.7%, n = 36). FFP transfusions (0.2%) contributed to the majority of the reactions followed by Red cell transfusion (0.15%). ATR were observed maximum in Hepato-biliary disease and liver transplantation patients (62%) followed by oncology patients (15%). The overall incidence of ATR in our study is 0.14% which is comparatively low compared to other studies due to well established hemovigilance systems. Adoption of more equipped methods & sensitive technology in various areas of blood banking will help to bring down the unwanted adverse transfusion reactions.

Noninfectious transfusion-associated adverse events and their mitigation strategies

Blood transfusions are life-saving therapies; however, they can result in adverse events that can be infectious or, more commonly, noninfectious. The most common noninfectious reactions include febrile nonhemolytic transfusion reactions, allergic transfusion reactions, transfusion-associated circulatory overload, transfusion-related acute lung injury, and acute and delayed hemolytic transfusion reactions. These reactions can be asymptomatic, mild, or potentially fatal. There are several new methodologies to diagnose, treat, and prevent these reactions. Hemovigilance systems for monitoring transfusion events have been developed and demonstrated decreases in some adverse events, such as hemolytic transfusion reactions. Now vein-to-vein databases are being created to study the interactions of the donor, product, and patient factors in the role of adverse outcomes. This article reviews the definition, pathophysiology, management, and mitigation strategies, including the role of the donor, product, and patient, of the most common noninfectious transfusion-associated adverse events. Prevention strategies, such as leukoreduction, plasma reduction, additive solutions, and patient blood management programs, are actively being used to enhance transfusion safety. Understanding the incidence, pathophysiology, and current management strategies will help to create innovative products and continually hone in on best transfusion practices that suit individualized patient needs.

Implementing simulation in oncology emergencies education: A quasi- experimental design

BACKGROUND

High-fidelity simulation (HFS) as a teaching-learning method has increased, especially in medical programs.

OBJECTIVE

This study was conducted to assess the effectiveness of using HFS on the satisfaction, self-confidence, self-efficacy, and knowledge of undergraduate students in oncology care.

METHODS

A pre-test post-test quasi-experimental design was utilized. Random sampling technique was used to recruit the participants. The scenarios including septic shock and infusion reaction were implemented. The training program including lectures and the simulation was run in a high fidelity simulation lab.

RESULTS

There was a significant difference (t=-5.95, p= 0.001) between the experimental group (M= 13.95, S⁢D= 3.35) and the control group (M= 6.25, S⁢D= 2.65) regarding knowledge, confidence (t=-22.75, p= 0.001) between the experimental group (M= 61.25, S⁢D= 12.10) and the control group (M= 38.50, S⁢D= 6.20), satisfaction level t=-18.25, p= 0.001; experimental group - M= 42.25, S⁢D= 4.25; and control group - M= 28.50, S⁢D= 3.15), and there was a significant difference between the experimental group (M= 35.50, S⁢D= 3.25) and control group (M= 24.25, S⁢D= 2.85) regarding self-efficacy (t=-13.25, p= 0.001).

CONCLUSIONS

High-fidelity simulation in nursing increased student knowledge, self-confidence, satisfaction, and self-efficacy in managing septic shock and infusion reaction as common oncology emergencies.

Reduction in adverse transfusion reactions with increased use of washed platelet concentrates in Japan-A retrospective multicenter study

Plasma removal by washing platelet concentrates (PCs) is effective in preventing adverse reactions to PC transfusions. The Japanese Red Cross Society (JRCS) started releasing washed PCs (WPCs) as a commercially approved blood product in September 2016. This retrospective multicenter study investigated the change in the number of transfused WPCs and the impact on the incidence of adverse reactions to PCs before and after the release. The numbers and types of transfused PCs and the adverse reactions to the PCs for a year before the start of the WPC release and for a year after the release were reported by 27 medical institutes in Japan. Transfusion information for approximately 8% of the amount of PCs supplied in Japan was analyzed during the study period. After the start of WPC release by the JRCS, the number of transfused WPCs doubled. The rate of adverse reactions to PCs decreased significantly (p = 0.0223), from 4.30% before the release to 4.05% after the release. The rates of adverse reactions to unwashed and WPCs were 4.13% and 0.84%, respectively. Allergic adverse reactions were significantly decreased after the release (3.60% before versus 3.37% after). No severe allergic reactions to WPCs were reported. The release of WPCs by the JRCS significantly reduced transfusion-related adverse reactions to PCs in Japan.

Immunoglobulin (Ig)G antibodies against IgE identified by basophil activation test as the putative causative agent of a serious allergic transfusion reaction: potential utility of the test as a new safety measure for allergic transfusion reactions

BACKGROUND

In most cases of allergic transfusion reactions (ATRs), the causative agents have not been identified and the mechanisms are largely unknown, with a few exceptions. The basophil activation test (BAT) was recently introduced in the field of transfusion to investigate the causal relationships between ATRs and transfusion, as well as the mechanisms behind them.

STUDY DESIGN AND METHODS

The BAT was used to screen the residual supernatants (SNs) of 43 blood components associated with serious ATRs for those that can activate basophils of many healthy volunteers. The SNs were then fractionated by centrifugal ultrafiltration and protein G column chromatography and each separated fraction was reexamined by the BAT.

RESULTS

Of the 43 such blood components, one activated basophils from 19 of 21 healthy volunteers. In the blood component, the IgG antibody against IgE was identified as a putative causative agent.

CONCLUSION

Blood donors who possessed the IgG antibody against IgE may be dangerous to transfusion recipients. The BAT would be useful in identifying such high-risk blood donors, when it is used to screen the blood components associated with serious ATRs for residual SNs that can activate the basophils of many healthy volunteers.

Recommendations on Selection and Processing of RBC Components for Pediatric Patients From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for selection and processing of RBC products in critically ill children developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children METHODS:: The panel of 38 experts developed evidence-based, and when evidence was lacking, expert-based clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The RBC processing subgroup included five experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Five recommendations reached agreement (> 80%). Irradiated cellular products are recommended for children at risk of transfusion-associated graft versus host disease due to severe congenital or acquired causes of immune deficiency or when the blood donor is a blood relative. Washed cellular blood components and avoidance of other plasma-containing products are recommended for critically ill children with history of severe allergic reactions or anaphylaxis to blood transfusions, although patient factors appear to be important in the pathogenesis of reactions. For children with history of severe allergic transfusion reactions, evaluation for allergic stigmata prior to transfusion is recommended. In children with severe immunoglobulin A deficiency with evidence of antiimmunoglobulin A antibodies and/or a history of a severe transfusion reaction, immunoglobulin A-deficient blood components obtained either from an immunoglobulin A-deficient donor and/or washed cellular components is recommended.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative consensus conference developed recommendations for selection and processing of RBC units for critically ill children. Recommendations in this area are largely based on pediatric and adult case report data.

Centrifugation-free washing: A novel approach for removing immunoglobulin A from stored red blood cells

Washed red blood cells (RBCs) are indicated for immunoglobulin A (IgA) deficient recipients. Centrifugation-based cell processors commonly used by hospital blood banks cannot consistently reduce IgA below the recommended levels, hence double washing is frequently required. Here, we describe a prototype of a simple, portable, disposable system capable of washing stored RBCs without centrifugation, while reducing IgA below 0.05 mg/dL in a single run. Samples from RBC units (n = 8, leukoreduced, 4-6 weeks storage duration) were diluted with normal saline to a hematocrit of 10%, and then washed using either the prototype washing system, or via conventional centrifugation. The efficiency of the two washing methods was quantified and compared by measuring several key in vitro quality metrics. The prototype of the washing system was able to process stored RBCs at a rate of 300 mL/hour, producing a suspension of washed RBCs with 43 ± 3% hematocrit and 86 ± 7% cell recovery. Overall, the two washing methods performed similarly for most measured parameters, lowering the concentration of free hemoglobin by >4-fold and total free protein by >10-fold. Importantly, the new washing system reduced the IgA level to 0.02 ± 0.01 mg/mL, a concentration 5-fold lower than that produced by conventional centrifugation. This proof-of-concept study showed that centrifugation may be unnecessary for washing stored RBCs. A simple, disposable, centrifugation-free washing system could be particularly useful in smaller medical facilities and resource limited settings that may lack access to centrifugation-based cell processors.

Transfusion-associated hazards: A revisit of their presentation

As a therapy or a support to other therapies, despite being largely beneficial to patients in general, transfusion it is not devoid of some risks. In a moderate number of cases, patients may manifest adverse reactions, otherwise referred to as transfusion-associated hazards (TAHs). The latest French 2016 haemovigilance report indicates that 93% of TAHs are minor (grade 1), 5.5% are moderate (grade 2) and 1.6% are severe (grade 3), with only five deaths (grade 4) being attributed to transfusion with relative certainty (imputability of level [or grade] 1 to 3). Health-care providers need to be well aware of the benefits and potential risks (to best evaluate and discuss the benefit-risk ratio), how to prevent TAHs, the overall costs and the availability of alternative therapeutic options. In high-income countries, most blood establishments (BEs) and hospital blood banks (HBBs) have developed tools for reporting and analysing at least severe transfusion reactions. With nearly two decades of haemovigilance, transfusion reaction databases should be quite informative, though there are four main caveats that prevent it from being fully efficient: (ai) reporting is mainly declarative and is thus barely exhaustive even in countries where it is mandatory by law; (aii) it is often difficult to differentiate between the different complications related to transfusion, diseases, comorbidities and other types of therapies in patients suffering from debilitating conditions; (aiii) there is a lack of consistency in the definitions used to describe and report some transfusion reactions, their severity and their likelihood of being related to transfusion; and (aiv) it is difficult to assess the imputability of a particular BC given to a patient who has previously received many BCs over a relatively short period of time. When compiling all available information published so far, it appears that TAHs can be analysed using different approaches: (bi) their pathophysiological nature; (bii) their severity; (biii) the onset scheme; (biv) a quality assessment (preventable or non-preventable); (bv) their impact on ongoing therapy. Moreover, TAHs can be reported either in a non-integrative or in an integrative way; in the latter case, presentation may also differ when issued by a blood establishment or a treating ward. At some point, a recapitulative document would be useful to gain a better understanding of TAHs in order to decrease their occurrence and severity and allow decision makers to determine action plans: this is what this review attempts to make. This review attempts to merge the different aspects, with a focus on the hospital side, i.e., how the most frequent TAHs can be avoided or mitigated.