Defining risk factors and presentations of allergic reactions to platelet transfusion

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.

Non-severe allergic transfusion reaction: A hidden cause of wastage of blood product and laboratory resources

BACKGROUND AND OBJECTIVES

Blood transfusions are often needlessly aborted following a non-severe allergic reaction despite responding well to medication resulting into partial transfusion of the implicated blood product. This results in the wastage of untransfused blood component and resources spent on unnecessary laboratory work-up of these reactions.

MATERIALS AND METHODS

We aimed to review the amount of blood product and laboratory resource wastage associated with non-severe allergic transfusion reaction (ATR) in a tertiary care hospital.

RESULTS

A total of 174,632 blood products were released and transfused during the study period (2019-2021). There were 336 adverse transfusion reactions with an estimated rate of 1.9 per 1000 blood products administered. Of 336, 145 (43%) were ATR, of which 141 (97%) were non-severe and 4 (3%) were severe. The most commonly associated symptom was found to be urticaria in 31 (22%). All non-severe ATR completely resolved with medication. Seventy-nine percent of the transfusions associated with non-severe ATRs were aborted, of which 37% were followed by additional transfusions. The estimated loss of blood product volume and the cost of non-severe ATR (including transfusion reaction work-up, discarded blood product and additional transfusion) was 11,185 ml (11 L) and Pakistani rupees 1,831,546 ($11,592.06 or €8598.78), respectively.

CONCLUSION

Non-severe ATR was found to be associated with a significant proportion of laboratory resource wastage and that of blood product in our institution. Revision of institutional guidelines for management and lab work-up of transfusion reactions would be helpful in alleviating this unnecessary loss in a resource-constraint transfusion-setting.

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.

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.

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 2: Prevention and monitoring

OBJECTIVE

To systematically review available evidence to develop guidelines for the prevention of transfusion reactions and monitoring of transfusion administration in dogs and cats.

DESIGN

Evidence evaluation of the literature (identified through Medline searches through Pubmed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. Evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. Evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines for prevention and monitoring were generated based on the synthesis of the evidence. Consensus on the final recommendations and a proposed transfusion administration monitoring form was achieved through Delphi-style surveys. Draft recommendations and the monitoring form were made available through veterinary specialty listservs and comments were incorporated.

RESULTS

Twenty-nine guidelines and a transfusion administration monitoring form were formulated from the evidence review with a high degree of consensus CONCLUSIONS: This systematic evidence evaluation process yielded recommended prevention and monitoring guidelines and a proposed transfusion administration form. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Pediatric Hemovigilance and Adverse Transfusion Reactions

Some types of transfusion reactions occur more frequently in the pediatric than the adult population. Allergic reactions are the most common, followed by nonhemolytic transfusion reactions; male children seem most susceptible to such reactions. Platelets are often implicated and pulmonary reactions are understudied in children. Clinical sequelae in neonates, such as bronchopulmonary dysplasia/chronic lung disease and intraventricular hemorrhage, have received increasing attention in relation to transfusion. There is a need to better understand the pathophysiology of transfusion reactions in neonatal and pediatric populations so preventive strategies can be undertaken. There is also a need for robust hemovigilance systems.

Solvent detergent treated pooled plasma and reduction of allergic transfusion reactions

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) patients have increased risk for allergic transfusion reactions (ATR) due to the number of plasma products they require. This study evaluated the efficacy of solvent detergent treated plasma (S/D treated plasma) to reduce ATRs.

STUDY DESIGN AND METHODS

All TTP patients who presented from April 2014 to February 2015 and experienced a moderate-severe ATR to untreated plasma with TPE were switched to S/D treated plasma (Octaplas) for their remaining procedures and included in the study. Patient records were retrospectively reviewed.

RESULTS

The overall ATR rate per procedure decreased from 35.0% (95% CI = 15.4%-59.2%) with untreated plasma to 1.4% ([1/73] 95% CI = 0.0%-7.4%) with S/D treated plasma. The moderate-severe ATR rate decreased from 20.0% ([4/20] 95% CI = 5.7%-43.7%) with untreated plasma to 0.0% ([0/73] 95% CI = 0.0%-4.9%) with S/D treated plasma. The overall ATR rate per plasma unit decreased from 2.6% (95%CI = 1.0%-5.1%) with untreated plasma to 0.1% (95% CI = 0.0%-0.4%) with S/D treated plasma. No patients experienced VTE while receiving untreated plasma. Four patients experienced VTE events while receiving S/D treated plasma. All patients who experienced a VTE had additional risk factors for VTE.

CONCLUSION

S/D plasma has promise as an effective product to reduce the risk of ATRs in TTP patients. Given the high risk of ATR in TTP patients, consideration of S/D plasma instead of untreated plasma for TPE in these patients may be warranted, especially for patients with a history of moderate to severe ATR. More extensive studies are needed to confirm these findings.

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.

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.

Mild Allergic Transfusion Reactions: Impact of Associated Clinical Symptoms?

Objectives

Transfusions are often needlessly aborted after occurrence of a mild allergic transfusion reaction (ATR), leading to wastage and reexposure of recipients to additional blood products (with potential alloimmunization). We aimed to determine the symptoms associated with such reactions (along with other parameters) as a possible reason of concern for transfusionists aborting such transfusions.

Methods

We reviewed the symptomology of all mild ATRs (as well as the associated wastage and costs of aborted transfusions) at an academic medical center that occurred over a period of 1 year.

Results

Of the patients, 52.3% had nonatopic-associated symptoms. The most common associated symptom was tachycardia (37.8%), followed by dyspnea (28.9%), hypotension (17.8%), and hypertension (13.3%). More than half of patients (54.7%) required retransfusion. The estimated cost of product wastage was $12,507.

Conclusions

Understanding symptoms associated with mild ATRs may lead to improved management of patients, with fewer unnecessary transfusions and less wastage.

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.

Transfusion Reactions

Transfusion reactions are common occurrences, and clinicians who order or transfuse blood components need to be able to recognize adverse sequelae of transfusion. The differential diagnosis of any untoward clinical event should always consider adverse sequelae of transfusion, even when transfusion occurred weeks earlier. There is no pathognomonic sign or symptom that differentiates a transfusion reaction from other potential medical problems, so vigilance is required during and after transfusion when a patient presents with a change in clinical status. This review covers the presentation, mechanisms, and management of transfusion reactions that are commonly encountered, and those that can be life-threatening.

Platelet proteins cause basophil histamine release through an immunoglobulin-dependent mechanism

BACKGROUND

A general understanding of allergic transfusion reaction mechanisms remains elusive. Multiple mechanisms have been proposed, but none have been compared experimentally.

STUDY DESIGN AND METHODS

We used histamine release (HR) from healthy human donor basophils to model allergic transfusion reactions. Platelet component supernatant (plasma), platelet lysate, and manipulated platelet lysates (dialyzed, delipidated, trypsinized, mild heat-inactivated, and ultracentrifuged) were used to characterize allergic stimuli. Immunoglobulin-dependent mechanisms were investigated through cell surface immunoglobulin depletion and ibrutinib signaling inhibition. HR induced by platelet mitochondria was compared with HR by platelet lysate with or without DNase treatment.

RESULTS

Robust, dose-responsive HR to platelet lysate was observed in two of eight nulliparous, never-transfused, healthy donors. No HR was observed with plasma. Among manipulated platelet lysates, only trypsin treatment significantly reduced HR (39% reduction; p = 0.008). HR in response to platelet lysate significantly decreased with either cell surface immunoglobulin depletion or ibrutinib pretreatment. Platelet mitochondria induced minimal basophil HR, and DNase treatment did not inhibit platelet lysate-induced HR.

CONCLUSION

Type I immediate hypersensitivity to platelet proteins may be an allergic transfusion reaction mechanism. Prior sensitization to human proteins is not required for basophil responses to platelet proteins. Further study into the relative contributions of hypersensitivity to platelet versus plasma proteins in transfusion is warranted.

A European survey on donor deferral for allergy: Rationale and initial results of a survey in 35 countries

Allergy accounts to near 0.5% of all reported transfusion adverse events. The responsibility of blood components themselves and - therefore - of blood donors is still questioned. The European Community undertook a large international survey to address the consistency and homogeneity of medical selection of blood donors with regard to the risk of allergy, and especially of transferring allergy to recipients. This short report presents the salient points of the survey, stressing that there is inconsistency in addressing the allergy question within countries or systems, with paths of improvement.

Factors related to allergic transfusion reactions and febrile non-haemolytic transfusion reactions in children

BACKGROUND AND OBJECTIVES

Allergic transfusion reactions (ATRs) and febrile non-haemolytic transfusion reactions (FNHTRs) are the two major types of transfusion-related adverse reactions (TRARs). Although prestorage leucocyte reduction and diversion of the first aliquot of blood (LR/D) could reduce FNHTRs and bacterial contamination in adult transfusion, ATRs are still problematic. In addition, there is little information about TRARs in paediatric population.

MATERIALS AND METHODS

We conducted a single-centre retrospective analysis of all transfusions, except washing products, and TRARs for 153 months to evaluate related factors such as delivery of treatment and the characteristics of recipients.

RESULTS

Most TRARs were FNHTRs and/or ATRs in children. In delivering blood products with LR/D, the frequencies of not only FNHTRs but also ATRs were significantly reduced with both platelet concentrates (PCs) and red cell concentrates (RCCs). TRARs of fresh-frozen plasma were infrequent in children. In addition, even after the introduction of LR/D, ATRs were significantly more frequent in patients with primary haematological and malignant diseases who received PCs and RCCs, older patients who received PCs and patients who received frequent RCCs.

CONCLUSION

These results suggest that leucocytes or mediators from leucocytes are underlying cause of ATRs in addition to FNHTRs in children. Furthermore, particular characteristics of patients would be other risk factors for ATRs.

Advances in environmental and occupational disorders in 2014

In 2014, the Journal published a number of studies that have advanced our understanding of the effects of various environmental factors and immune responses in patients with allergic diseases. In this review we emphasize reports that have appeared in the Journal over the past year that deal with environmental and occupational respiratory disorders and novel approaches to their treatment. The review will focus on the effects of environmental factors and immune responses in allergic airway diseases, identification of new allergens, and risk factors in stinging insect allergy, development of asthma in different age groups, effects of viral infections, and benefits of new therapies.

Transfusion-related adverse events in the Platelet Dose study

BACKGROUND

How platelet (PLT) product characteristics such as dose, source (whole blood derived [WBD] vs. apheresis), storage duration, and ABO matching status affect the risks of transfusion-related adverse events (TRAEs) is unclear. Similarly, more information is needed to define how recipient characteristics affect the frequency of TRAEs after PLT transfusion.

STUDY DESIGN AND METHODS

In the multicenter Platelet Dose ("PLADO") study, pediatric and adult hematology-oncology patients with hypoproliferative thrombocytopenia were randomized to receive low-dose (LD), medium-dose (MD), or high-dose (HD) PLT prophylaxis for a pretransfusion PLT count of not more than 10 × 10(9) /L. All PLT units (apheresis or WBD) were leukoreduced. Post hoc analyses of PLADO data were performed using multipredictor models.

RESULTS

A total of 5034 PLT transfusions to 1102 patients were analyzed. A TRAE occurred with 501 PLT transfusions (10.0%). The most common TRAEs were fever (6.6% of transfusions), allergic or hypersensitivity reactions (1.9%), and sinus tachycardia (1.8%). Patients assigned HD PLTs were more likely than LD or MD patients to experience any TRAE (odds ratio for HD vs. MD, 1.50; 95% confidence interval, 1.10-2.05; three-group comparison p = 0.02). PLT source and ABO matching status were not significantly related to overall TRAE risk. Compared to a patient's first PLT transfusion, subsequent PLT transfusions were less likely to have a TRAE reported, primarily due to a lower risk of allergic or hypersensitivity reactions.

CONCLUSION

The most important PLT unit characteristic associated with TRAEs was PLT dose per transfusion. HD PLTs may increase the risk of TRAEs, and LD PLTs may reduce the risk.

Transfusion and component characteristics are not associated with allergic transfusion reactions to apheresis platelets

BACKGROUND

Transfusion-related characteristics have been hypothesized to cause allergic transfusion reactions (ATRs) but they have not been thoroughly studied. The primary objective of this study is to evaluate the associations of infusion rate, infusion volume, ABO mismatching, component age, and pretransfusion medication with the incidence and severity of ATRs. A secondary objective is to compare the risk of these attributes relative to the previously reported risk factor for aeroallergen sensitization in transfusion recipients, as measured by an aeroallergen-specific immunoglobulin (Ig)E antibody screen.

STUDY DESIGN AND METHODS

Clinical and transfusion-related data were collected on subjects with reported ATRs and uneventful (control) apheresis platelet (PLT) transfusions over a combined 21-month period at two academic medical centers. Control transfusions were selected as the next uneventful transfusion after an ATR was reported. Logistic regression, Mann-Whitney, and t tests were used to assess associations with ATRs. Previously reported aeroallergen-specific IgE screening data were incorporated into a multivariable logistic regression.

RESULTS

A total of 143 ATRs and 61 control transfusions were evaluated among 168 subjects, ages 2 to 86 years. Infusion rate, infusion volume, ABO mismatching, component age, and pretransfusion medication showed no significant association with ATRs (p > 0.05). Neither infusion rate nor infusion volume increased the risk of anaphylaxis versus mucocutaneous-only ATRs. Aeroallergen sensitization has previously been associated with ATRs. After transfusion-related covariates were controlled for, aeroallergen sensitization remained significantly associated with ATRs (odds ratio, 2.68; 95% confidence interval, 1.26-5.69).

CONCLUSIONS

Transfusion- and component-specific attributes are not associated with ATRs. An allergic predisposition in transfusion recipients is associated most strongly with ATR risk.