Universal leukoreduction decreases the incidence of febrile nonhemolytic transfusion reactions to RBCs

A randomized control trial to compare mortality in recipients of leucoreduced and non-leucoreduced whole blood transfusion in patients with cancer in Uganda

BACKGROUND

Mortality benefit of transfusion with leucoreduced whole blood has not been demonstrated in the sub-Saharan Africa (SSA). We compared mortality in patients with cancer transfused with leucoreduced and non-leucoreduced whole blood in a SSA setting.

METHODS

An open-label randomized controlled trial was conducted at the Uganda Cancer Institute where participants were randomized in a 1:1 ratio into the leucoreduced and non-leucoreduced whole blood transfusion arms. Leucocyte filtration of whole blood was performed within 72 h of blood collection. Patients aged ≥ 15 years who were prescribed blood transfusion by the primary physicians were eligible for study enrolment. Mortality difference was analyzed using intention-to-treat survival analysis and cox proportional hazard model was used to analyze factors associated with mortality.

RESULTS

There were 137 participants randomized to the leucoreduced and 140 to the non-leucoreduced arms. Baseline characteristics were similar between the two arms. The median number of blood transfusions received was 1 (IQR, 1-3) unit and 2 (IQR, 1-3) units in the leucoreduced and non-leucoreduced arms respectively, p = 0.07. The 30-day mortality rate in the leucoreduced arm was 4.6% (95% CI, 2.1-10) and was 6.2% (95% CI, 3.2-12.1) in the non-leucoreduced arm (p = 0.57), representing an absolute effect size of only 1.6%. Increasing age (HR = 0.92, 95% CI, 0.86-0.98, p = 0.02) and Eastern Co-operative Oncology Group (ECOG) performance score of 1 (HR = 0.03, 95% CI, 0.00-0.31, p < 0.01) were associated with reduced 30-day mortality.

CONCLUSIONS

The study failed to demonstrate mortality difference between cancer patients transfused with leucoreduced and non-leucoreduced whole blood. Although this study does not support nor refute universal leucoreduction to reduce mortality in patients with cancer in SSA, it demonstrates the feasibility of doing transfusion RCTs in Uganda, where a multi-center trial with an appropriate sample size is needed.

TRIAL REGISTRATION

Pan African Clinical Trial Registry, https://pactr.samrc.ac.za/ (PACTR202302787440132). Registered on 06/02/2023.

Transfusion safety: Is there a difference between reported reactions in low-to-middle income and high-income countries?

BACKGROUND AND OBJECTIVES

Transfusion safety may be becoming dependent on the financial resources made available for transfusion structures and may vary between high-income countries (HIC) and low-to-middle-income countries (LMIC). To assess whether there is a difference in the reported TR between these two groups of countries, we examined TR reported in Tunis the capital of Tunisia, a LMIC, and compared their frequency with reported TR in HIC.

MATERIALS AND METHODS

Data of TR were collected from transfusion incident report (TIR) forms declared by healthcare facilities in Tunis between 2015 and 2019. They were analysed and compared to reported TR in France (ANSM) and UK (SHOT).

RESULTS

The incidence of TR was 70.6/100 000 blood components (BP) issued. A third of TR (36.8%) occurred at night. Febrile non-hemolytic transfusion reactions (43.7%) and allergic reactions (35%) were the most reported TR respectively 22.4/100 000 BP and 17.9/100 000 BP. The rate of ABO incompatibilities was 1.96/100 000 red blood cell units (RBC): they were all caused by human error. The rates of TRALI, TACO and bacterial contaminations were respectively 1.26/100 000 BP, 1.4/100 000 RBC and 0.7/100 000 BP.

CONCLUSION

While advanced technologies applied to transfusion have improved transfusion safety, this study shows that their impact has been relatively minor, as reported TR in LMIC are still comparable to those in HIC. ABO-incompatibilities are still higher in LMIC: this should be addressed by reinforcing the training of all healthcare personnel involved in transfusion medicine.

What's in Your Transfusion? A Bedside Guide to Blood Products and Their Preparation

An understanding of the contents of blood products and how they are modified before transfusion will help any physician. This article will review five basic blood products and the five most common product modifications.

Evaluation of leukocyte depletion of packed red blood cell units and impact on clinically observed transfusion reactions

Introduction

The aim of this retrospective study was to determine whether there is an association between leukoreduction of packed red blood cell (pRBC) units and reduction of clinically observed transfusion reactions (TR), particularly febrile non-haemolytic transfusion reactions (FNHTR), and better outcomes in dogs. Secondary aims were to evaluate the effects of other factors suspected to influence transfusion reaction frequency or survival, including crossmatching, use of immunosuppressive drugs, and age and number of the blood products being administered.

Materials and methods

Medical data on dogs transfused with leukocyte-reduced (LR) and non-leukocyte-reduced (N-LR) pRBC units at the Animal Hospital Zürich, University of Zürich, Switzerland between January 1, 2007, and December 17, 2018 were searched. Before 2014, only N-LR blood were transfused. After 2014, both LR and N-LR blood were available.

Results

A total of 339 canine patients were transfused with 413 pRBC units; 30.5% (126/413) were LR units and 69.5% (287/413) were N-LR. Data collected from medical records was analyzed using univariate and multivariate logistic regression. In the present study, TR occurred in 19.8% of pRBC units (25/126) with LR and in 17.7% (51/287) of pRBC with N-LR; p > 0.05. FNHTR occurred in 6.3% of pRBC units (8/126) with LR and in 4.5% (13/287) of those with N-LR; p > 0.05. There was no correlation between the occurrence of TR and discharge from hospital (p > 0.05). Crossmatching, immunosuppressive therapy, and age of the blood product were not associated with the frequency of TR; p > 0.05 for all. The duration of survival days was not related to the number of transfusions dogs received.

Discussion

In the present study, the leukocyte-depletion of transfused pRBC units was not associated with fewer TR nor to fewer FNHTR compared to N-LR units. Discharge of dogs from hospital was not dependent on the occurrence of TR.

Investigation of the patients with recurrent acute transfusion reactions: A single tertiary medical centre experience

OBJECTIVE

To assess the spectrum of patients who developed recurrent acute transfusion reactions (TRs) and to characterize these recurrent TRs.

METHODS

This retrospective study included patients who developed ≥2 acute TRs between April 2017 and March 2020 in a tertiary medical centre.

RESULTS

Among 216 TRs that occurred after 2024 transfusions in 87 patients, 66 (75.9%) patients reported a history of transfusions before the first TR and 70 (80.5%) patients received further transfusions after the last TR; with the same type of TR and reaction to the same type of blood product observed in 59 (67.8%) patients and 56 (64.4%) patients, respectively. TRs were most commonly associated with packed red blood cell (PRBC) transfusions and a febrile non-haemolytic transfusion reaction (FNHTR) was the most common type of TR. However, leukocyte reduced (LR) PRBCs were less common than LR platelets among transfusions with TR (22.7% [27/119] versus 75.0% [57/76], respectively) and premedication was prescribed before 196 of 216 (90.7%) transfusions with TR.

CONCLUSION

Most patients with recurrent TRs received repeated transfusions in addition to transfusions with TR. Instead of considering premedication, an increase in the use of LR might be the strategy to reduce the recurrence of TR.

Comparative study of quality of leukoreduced packed red blood cell units as assessed by nageotte hemocytometry and flow cytometry

PURPOSE

Assessment of residual white blood cell (rWBC) count is vital to ascertain the quality of leukodepleted (LD) blood components. Automated cell analyzers lack the sensitivity for the assessment of very few leukocytes as found in LD blood components. Flow Cytometry (FC) based methods and Nageotte hemocytometer are the most commonly used techniques for this purpose. The objective of this study was to compare the use of Nageotte hemocytometer and FC for quality control of LD red blood cell units.

MATERIALS AND METHODS

A prospective, observational study was conducted in the Department of Immunohematology and Blood Transfusion of a tertiary care center from September 2018 to September 2020. About 303 LD-packed red blood cell units were tested by FC and Nageotte hemocytometer for rWBCs.

RESULTS

The number of rWBC (mean) detected by flow cytometer and Nageotte's hemocytometer was 1.06 ± 0.43 white blood cell (WBC)/μL and 0.67 ± 0.39 WBC/μL, respectively. Coefficient of variation was 58.37% by Nageotte hemocytometer method and 40.46% by FC. Linear regression analysis did not show any correlation (R2= 0.098, P = 0.001) whereas Pearson's correlation coefficient showed a weak relation (r = 0.31) between the two methods.

CONCLUSION

Flow cytometric technique provides a more precise and accurate objective tool compared to Nageotte hemocytometer which is labor intensive, time consuming, and prone to errors arising out of subjectivity along with reported underestimation bias. In the absence of adequate infrastructure, resources, and trained workforce, Nageotte hemocytometer method is a reliable alternative. Nageotte's chamber could be best used in the resource-constrained setup as it offers a relatively inexpensive, simple, and viable means to enumerate rWBCs.

Blood Transfusion in Equids—A Practical Approach and Review

Simple Summary

Transfusion medicine is an accessible, technically simple, and often lifesaving tool that can be used in both field and hospital settings, in cases of significant bleeding or anemia. A thorough understanding of the indications, methodology and complications of blood transfusion allows the practitioner to identify cases where administration of whole blood is necessary, and how to safely perform the transfusion. This review collects the current literature surrounding blood transfusion into one readily accessible document to allow clinicians a comprehensive understanding of all aspects of equine blood transfusion, while serving as a reference for performing these procedures.

Abstract

Transfusion medicine is a crucial part of equine intensive and critical care. Blood transfusions can save lives in both acute and chronic cases of anemia, hemorrhage, and hemolysis. It is vital to have a comprehensive theoretical and practical understanding of the techniques, implications, risks, and complications. This review covers the physiology and pathophysiology of conditions requiring transfusion, as well as step by step guidance for practitioners of all experience levels. This review is designed to serve as a practical reference for those who are treating horses in either the field or hospital setting. It aims to provide both theoretical background and easy to locate formulae with guidance that is easy to refer to in a critical situation. When risks and benefits are well understood, these techniques can be confidently employed in critical situations to improve outcomes and save lives.

Sickle cell trait results in a high leukoreduction quality control failure rate for whole blood donations

Background

Prior studies have shown that sickle cell trait (SCT) is the most common reason attributed to leukoreduction (LR) filter failure due to physical blockage. However, current Food and Drug Administration (FDA) guidelines do not require blood collectors to take a specific action to mitigate inadequate LR that may occur among donors with SCT. We sought to determine the scope of inadequate LR among whole blood (WB) donations collected from individuals with SCT and processed under standard manufacturing conditions.

Study Design and Methods

Between 8/2021 and 2/2022, a total of 40 red blood cells units (RBCs) manufactured from WB donations collected from donors historically positive for SCT had residual leukocyte testing performed. All 40 of the units had appeared to successfully complete leukofiltration.

Results

Out of the 40 units tested, 22 failed routine residual leukocyte quality control testing (55% failure rate, 95% confidence interval 40%–70%). Nine out of the 22 failures resulted in more than 100 residual leukocytes per microliter of product.

Conclusion

Even when leukofiltration appears to have been completed successfully, WB units collected from donors with SCT have a high (55% in aggregate) rate of inadequate leukoreduction. Correlating this result with previous studies showing that of up to 50% of WB units collected from donors with SCT fail to pass through the leukoreduction filter, we estimate that only 25% of WB donations collected from individuals with SCT will result in a leukoreduced RBC unit that meets all FDA requirements. Blood centers should encourage individuals with SCT to donate platelets or plasma, rather than WB.

See editorial on page 1683–1687, in this issue

Changes in the incidence of transfusion reactions in hematological patients over the past 30 years

BACKGROUND

Patients with hematological diseases are polytransfused and often immunocompromised, therefore susceptible to transfusion reactions (TR). This study aims to document the incidence of TRs in adult hematological patients and assess the effect of changes in the production of blood components and transfusion practice on their occurrence.

STUDY DESIGN AND METHODS

Retrospective observational analysis of TRs reported from 1993 to 2019 was performed. For the analysis of the effect of changes on the incidence of TRs, the evaluated time was divided into two periods: the 1st period before the introduction of changes in production, when leukoreduced blood components were used only selectively, and the 2nd period, when semi-automated method of production and universal leukoreduction was introduced.

RESULTS

The decrease in the incidence of TRs was observed for both red blood cell (RBC) and platelet concentrate (PC) transfusions in the 2nd period. Since platelet additive solution has been used, a further decrease in the incidence was reported. The decrease in incidence was also observed for delayed hemolytic/serological transfusion reactions and for transfusion-transmitted bacterial infections. Four cases of incorrect blood transfusions were uniquely related to the hematological patients, caused by antigen loss and transfusion ordering after ABO-incompatible hematopoietic stem cell transplantation.

DISCUSSION

Our results provided evidence that the introduction of tools offered by modern transfusion medicine: universal leukodepletion, plasma replacement with additive solutions, sensitive laboratory techniques, prophylactic antigen matching policy, informatization, and automatization, decreased the incidence of TRs and improved transfusion safety.

The influence of leukoreduction on the acute transfusion-related complication rate in 455 dogs receiving 730 packed RBCs: 2014-2017

OBJECTIVE

To investigate the influence of prestorage leukoreduction of packed RBCs (pRBCs) on acute transfusion-related complication rate in dogs.

SETTING

Two private referral hospitals.

DESIGN

Retrospective case study.

ANIMALS

Four hundred and fifty-five dogs receiving nonleukoreduced (nLR) or leukoreduced (LR) pRBC between January 1, 2014 and July 31, 2017.

MEASUREMENTS AND MAIN RESULTS

Transfusions were retrospectively reviewed to record data about the patient, donor, unit, transfusion event, acute complications, hospital discharge, and cause of death. Of 730 transfusion events in 455 dogs, 288 used LR pRBC and 442 used nLR pRBC. There was a 18.9% (138/730) overall complication rate. Seven (0.96%) complications were life-threatening. The most common complications were pyrexia (5.6%), gastrointestinal signs (4.9%), and hemolysis with no other signs (4.1%). Pyrexia with no other clinical signs, consistent with a febrile nonhemolytic transfusion reaction (FNHTR), occurred in 3.2% of transfusion events. There was a significant (P = 0.03) decrease in the rate of FNHTR with LR pRBC (1%) versus nLR pRBC (4.5%). Use of LR pRBC did not decrease in-hospital mortality. The odds of any complication, hemolysis only, FNHTR, and more severe complications increased with pRBC age. Leukoreduction did not decrease the impact of pRBC age on these complications. Use of older pRBC did not increase the incidence of life-threatening complications or mortality. Dogs receiving pRBC for blood loss were more likely to have gastrointestinal and more severe complications than those dogs that had hemolysis. The effect of pRBC unit age on complications was not influenced by the underlying reason for transfusion. Dogs that received a previous transfusion were more likely to have respiratory complications.

CONCLUSION

In this study, the use of LR pRBC was associated with a decreased rate of FNHTR but no other complications. Unit age was associated with the incidence of hemolysis, FNHTR, and complication severity but not the rate of life-threatening complications or mortality.

Development and implementation of a hemovigilance program at a university veterinary teaching hospital

OBJECTIVE

To describe the development and implementation of a small animal hemovigilance program at a university veterinary teaching hospital.

DESIGN

Retrospective observational descriptive study performed between October 2014 and March 2019.

SETTING

University teaching hospital.

ANIMALS

Dogs and cats receiving blood product transfusions .

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

 A hemovigilance working group composed of veterinary specialists in clinical pathology, internal medicine, and emergency and critical care was established. This group developed evidence-based definitions of transfusion reactions, reaction classification systems, and a transfusion reaction reporting form. The reporting form contained sections for patient information, transfusion information, administration details, and reaction details. Reaction events were classified by reaction type, severity grade, and imputability to the transfusion. Following implementation of the hemovigilance program, transfusion reaction data were collected and examined for the period spanning October 2014 and March 2019. During the study period, 718 canine transfusions (4 whole blood, 400 packed RBC [pRBC], 300 fresh frozen plasma [FFP], 7 platelet rich plasma, and 7 cryoprecipitate) and 124 feline transfusions (5 whole blood, 95 pRBC, and 24 FFP) were administered. There were 32 total reactions (27 canine and 5 feline), with the most common reaction being febrile nonhemolytic transfusion reactions (19/32; 59%). The incidence rate of transfusion reactions was found to be 3.8% in dogs and 4.0% in cats. For the confirmed reactions, classification criteria for case definition, reaction severity grade, and imputability were able to be determined and recorded. This allowed targeted interventions to be implemented in order to potentially reduce future reactions.

CONCLUSIONS

A hemovigilance program can be instituted successfully in a veterinary hospital setting and once developed, standardized reporting tools could be utilized by multiple hospitals and provide the basis for more widespread reaction reporting in veterinary medicine.

Factors Involved in the onset of infection following bacterially contaminated platelet transfusions

Transfusion of platelet concentrates (PCs) is associated with several adverse patient reactions, the most common of which are febrile non-hemolytic transfusion reactions (FNHTRs) and transfusion-associated bacterial-infection/transfusion-associated sepsis (T-ABI/TA-S). Diagnosis of T-ABI/T-AS requires a positive blood culture (BC) result from the transfusion recipient and also a positive identification of bacterial contamination within a test aliquot of the transfused PC. In a significant number of cases, clinical symptoms post-transfusion are reported by the clinician, yet the BCs from the patient and/or PC are negative. The topic of 'missed bacterial detection' has therefore been the focus of several primary research studies and review articles, suggesting that biofilm formation in the blood bag and the presence of viable but non-culturable (VBNC) pathogens are the major causes of this missed detection. However, platelets are emerging as key players in early host responses to infection and as such, the aforementioned biofilm formation could elicit 'platelet priming', which could lead to significant immunological reactions in the host, in the absence of planktonic bacteria in the host bloodstream. This review reflects on what is known about missed detection and relates this to the emerging understanding of the effect of bacterial contamination on the platelets themselves and the significant role played by platelets in exacerbation of an immune response to infection within the transfusion setting.

Laboratory and clinical comparison of the efficacy of prestorage leukoreduction of red cells at cold versus room temperature

BACKGROUND

The temperature at which filtration takes place has been reported to influence the efficacy of leukoreduction. We aimed to compare the residual leukocyte count (RLC) in red cell units (RCUs) filtered at cold (CT) versus room temperature (RT) and to assess whether this correlates clinically with a difference in the incidence of acute transfusion reactions (ATRs).

METHODS AND MATERIALS

In the first part of the study, whole blood units collected were randomly allocated for subsequent filtration at CT and RT, respectively. RLC postfiltration was assessed using flow cytometry. The second part of the study was a nonrandomized clinical trial in which incidence of ATR was compared between RCUs filtered at RT and CT for 6 months each.

RESULTS

Thirty-five RCUs each underwent leukofiltration at CT and RT, respectively. The median RLCs in the filtered units at CT and RT were 0.02 × 10⁶ and 0.1 × 10⁶ leukocytes/unit, respectively (p = .0001), with no difference in red blood cell (RBC) recovery (p = .41). During the second part, 3455 RCUs filtered at RT and 3539 RCUs filtered at CT were transfused to patients. The rate of febrile non-hemolytic transfusion reaction (FNHTR) among transfused patients was less with units filtered at CT (1 per 2000 transfusions) in comparison to RT (1 per 588 transfusions). The difference was, however, not significant (p = .14).

CONCLUSION

If change in temperature alone can cause significant reduction in leukocytes, then it is a simple way to curtail the rate of this common yet unpleasant reaction and reduce the reaction rate at minimal cost.

Randomized double-blinded clinical trial on acute transfusion reactions in dogs receiving leukoreduced versus nonleukoreduced packed red blood cells

Background

Leukoreduction of blood products is commonly performed in human medicine, but its effect on outcome or incidence of transfusion reactions (TRs) in dogs is unknown.

Objectives

To prospectively evaluate the incidence of acute TRs in, and the outcome of, dogs receiving either leukoreduced (LR) or nonleukoreduced (N‐LR) packed red blood cells (PRBC).

Animals

Dogs (n = 194) administered PRBC between August 2017 and June 2020.

Methods

Prospective randomized double‐blinded clinical trial. Dogs were randomized to receive either LR or N‐LR PRBC and clinicians, nurses and investigators were blinded to the group allocations. The incidence of TRs, change in PCV, hospitalization duration, and survival to discharge were recorded.

Results

Out of the 194 dogs, 96 received LR and 98 received N‐LR PRBCs. The mean 12‐hour change in PCV value was +9.22% (SD 5.27%) for dogs that received N‐LR and +10.69% (SD 6.44%) for dogs that received LR PRBC (effect size 0.26, 95% confidence interval [CI] −0.02 to 0.55), which was not significantly different (P = .08). TRs were documented in 16/194 (8.24%) dogs, with 1/194 (0.51%) being a mild allergic reaction, while 15/194 (7.73%) had suspected febrile nonhemolytic TRs (FNHTRs). FNHTR incidence was not significantly different between the LR (6/96, 6.25%, 95% CI 2.8‐13.56) and N‐LR (9/98, 9.18%, 95% CI 4.92‐17.11) groups (P = .81). Of the 156 dogs that survived to discharge, 80/156 received N‐LR PRBC and 76/156 received LR PRBC which was not significantly different (P = .66).

Conclusions and Clinical Importance

A clinical advantage of using LR over N‐LR PRBC in terms of TRs and increase in PCV after transfusion was not detected.

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 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.

Autologous blood salvage in cardiac surgery: clinical evaluation, efficacy and levels of residual heparin

OBJECTIVE

Intraoperative blood salvage (cell saver technique) in cardiac surgery is universally used in surgical procedures with a marked risk of blood loss. The primary objectives of this study were to determine the concentration of residual heparin in the final product that is reinfused into the patient in the operating room and to evaluate the efficacy and safety of the cell saver technique.

METHOD

Twelve patients undergoing elective cardiac surgery were enrolled in this study. Using the XTRA Autotransfusion System, blood samples were collected from the cardiotomy reservoir, both prior to blood processing (pre-sample) and after it, directly from the bag with processed product (post-sample). Hematocrit and hemoglobin levels, the protein, albumin and residual heparin concentrations, hemolysis index, and the platelet, erythrocyte and leukocyte counts were measured.

RESULTS

Hematocrit and hemoglobin levels and red blood cell counts were higher in post-processing samples, with a mean variation of 54.78%, 19.81g/dl and 6.84×106/mm3, respectively (p<0.001). The mean hematocrit of the processed bag was 63.49 g/dl (range: 57.2-67.5). The residual heparin levels were ≤0.1IU/ml in all post-treatment analyses (p=0.003). No related adverse events were observed.

CONCLUSION

The reduced residual heparin values (≤0.1IU/ml) in processed blood found in this study are extremely important, as they are consistent with the American Association of Blood Banks guidelines, which establish target values below 0.5IU/ml. The procedure was effective, safe and compliant with legal requirements and the available international literature.

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.

Optimizing the recovery of peripheral blood mononuclear cells trapped in leukoreduction filters - A comparison study

Introduction

The isolation of captured peripheral blood mononuclear cells (PBMNCs) from leukoreduction filters (LRFs) can be of great importance in terms of bringing the lost cells back into use.

Objective

The aim of this study was to evaluate various methods based on their potential to recover the peripheral blood cells from LRFs with a focus on mononuclear cells (MNCs).

Method

For cell isolation from LRFs, three distinct methods (back-flushing, direct and vacuum pump) were compared through the calculation of the yield of isolated MNCs. The viability of extracted cells was determined by the flow cytometry technique. Moreover, the recovered MNCs were characterized regarding the presence of blood stem cell purification. The cell culture, microscopic observation, and immunophenotyping were employed to characterize the blood stem cells (hematopoietic, mesenchymal and progenitor endothelial stem cells).

Results

The yield of isolation obtained in the back-flushing, direct and vacuum pump methods were 17.7 ± 1.28, 17.3 ± 0.96 and 21.2 ± 0.90 percent, respectively. Although the highest potential for total blood cell recovery belonged to the vacuum pump method, the lowest cell viability (85.73 ± 4.84%) was observed in this method. However, the isolation process of the back-flushing and direct methods had less effect on cell viability. The characterization of the isolated MNCs displayed that the dominant positive phenotype was for CD34/CD45, indicating hematopoietic stem cells. In addition, the endothelial stem/progenitor cells were significantly detected as CD31/CD133 positive cells.

Conclusion

According to our results and considering the safety and efficiency potential of each of the applied methods, the back-flushing in comparison with the other methods can be considered a suitable procedure for MNC isolation from LRFs.

A comparison between leukocyte reduced low titer whole blood vs non-leukocyte reduced low titer whole blood for massive transfusion activation

BACKGROUND

Hemorrhagic shock is the leading cause of survivable death in trauma patients and recent literature has focused on resuscitation strategies including transfusing low-titer group O whole blood (LTOWB). Debate remains regarding whether leukocyte reduced (LR) whole blood is of clinical benefit or detriment to patients requiring massive transfusion. This study compares survival outcomes between LR-LTOWB and non-LR LTOWB.

STUDY DESIGN AND METHODS

The objective of this prospective, observational study was to detect any difference in 24-hour survival between patients receiving LR-LTOWB and non-LR LTOWB during their massive transfusion activation. Secondary objectives were to report any difference in ICU LOS, ventilation days, in-hospital survival, and hospital LOS. Data collected included patient sex, age, mechanism of injury, Injury Severity Score (ISS), Trauma Injury Severity Score (TRISS), cause of death, and number of LTOWB transfused.

RESULTS

A total of 167 patients received 271 LTOWB transfusions. There were 97 patients that received 168 units of LR-LTOWB while 70 patients received 103 units of non-LR LTOWB. The two study groups were comparable in terms of age, sex, ISS, TRISS, and the number of LTOWB transfused. The use of LR LTOWB during the initial massive transfusion activation in traumatically injured patients was not associated with increased 24-hour survival compared to when using non-LR LTOWB. No transfusion associated adverse events were reported.

CONCLUSIONS

The administration of either LR or non-LR LTOWB was not associated with >24 hours survival in patients presenting with massive hemorrhage. The high cost and the rapid decline in platelet count of LR whole blood may be a consideration.

Neutrophil extracellular traps in stored canine red blood cell units

Background

Neutrophil extracellular traps (NETs), webs of DNA and citrullinated histones extruded from activated neutrophils cause transfusion‐related acute lung injury. Supernatants of stored red blood cell (RBC) units might promote NETosis in neutrophils from the units or from transfusion recipients.

Hypotheses

(1) NETs form during storage of canine RBC, (2) leukoreduction (LR) before storage of RBC reduces NETosis, and (3) supernatant from stored, nonleukoreduced (NLR) RBC units induces NETosis in healthy canine neutrophils modeling transfusion recipients.

Animals

Six healthy purpose‐bred research dogs were utilized for blood donation.

Methods

Prospective controlled study. RBC units were collected from each dog, aseptically divided into 2 equal subunits, 1 of which was leukoreduced, and stored for 42 days. Stored units were sampled biweekly for quantification of NET markers citrullinated histone H3 (Western blot) and cell‐free DNA (cfDNA) (DNA dye binding). Unit supernatants were applied ex vivo to canine neutrophils and extracellular DNA release representing NETosis was assessed.

Results

Markers of NETs increased during RBC storage (cfDNA P < .0001 and citrullinated H3 P = .0002) and were higher in NLR than LR units (day 42 LR cfDNA 0.34 ± 0.82 ng/mL vs day 42 NLR 1361.07 ± 741.00 ng/mL, P < .0001; day 42 LR citrullinated H3 0.19 ± 0.13 AU vs NLR 0.57 ± 0.34 AU, P = .007). Isolated neutrophils did not form NETs when exposed to stored canine RBC supernatant.

Conclusions and Clinical Importance

NETosis occurs in stored canine NLR RBC units, and is attenuated by LR before storage. NETs might be mediators of transfusion reactions.

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.

Quality and safety measures in transfusion practice: The experience of eight southern/eastern Mediterranean countries

BACKGROUND AND OBJECTIVES

Blood transfusion is inherently associated with risks, and little is known regarding the available quality and safety measures in developing countries. No studies or census has been carried out, and therefore, no data on this compelling issue are available.

MATERIALS AND METHODS

Data emanating from eight Arabic eastern/southern Mediterranean countries who responded to five surveys were collected and tabulated.

RESULTS

Asepsis during phlebotomy, screening for serological and immuno-haematological parameters and appropriate storage conditions are maintained across all countries. Variations in blood component processing exist. Universal leucoreduction is systematically applied in Lebanon. Nucleic acid testing is only performed in Egypt. Aphaeresis procedure, leucoreduction and quality control for blood components are virtually inexistent in Mauritania. Written donor questionnaire is absent in Algeria and Tunisia. Most donor deferral periods for infectious agents are inconsistent with international standards.

CONCLUSION

Gaps in the processing and in the quality/safety measures applied to the manufacture of blood components are quite evident in most eastern/southern Mediterranean countries. The decision of establishing an effective collaboration network and an independent body - aside from WHO - composed of specialists that oversees all transfusion activities in these countries is certainly a crucial step towards ensuring an optimum level of blood safety.

Premedication for the prevention of nonhemolytic transfusion reactions: a systematic review and meta-analysis

BACKGROUND

The efficacy of premedication for the prevention of nonhemolytic transfusion reactions remains controversial. This systematic review and meta-analysis assessed the effect of premedication on the rate of nonhemolytic transfusion reactions after allogeneic blood transfusion.

STUDY DESIGN AND METHODS

We searched the literature using CENTRAL, MEDLINE, EMBASE, ISI Web of Science, and clinicaltrials.gov databases from inception until October 31, 2018. We included all randomized controlled trials comparing premedication to placebo or no treatment in patients receiving any labile blood product. Outcome measures were reported as relative risks (RRs) with 95% confidence intervals (CIs). Data were combined for similar outcomes where appropriate using a random-effects model. Analyses were done at both the patient and transfusion level.

RESULTS

Three randomized trials using acetaminophen and antihistamine as premedication met the inclusion criteria. A total of 517 patients received 4444 red blood cell or platelet transfusions. Pooled patient-level estimates with premedication for all nonhemolytic, febrile nonhemolytic, and minor allergic reactions were RR, 0.92 (95% CI, 0.63-1.35); RR, 0.54 (95% CI, 0.26-1.1); and RR, 1.37 (95% CI 0.81-2.31), respectively. Transfusion-level analyses also showed no benefit with premedication. Of 517 patients randomized, only 27 (5.2%) had a history of transfusion reactions.

CONCLUSION

Routine premedication with acetaminophen and antihistamines did not prevent nonhemolytic transfusion reactions; however, the estimate of effect was greatest for febrile reactions. The impact of premedication in patients with a prior history of transfusion reactions remains unknown and requires further evaluation in future clinical trials.

Review of current transfusion therapy and blood banking practices

Transfusion Medicine is a dynamically evolving field. Recent high-quality research has reshaped the paradigms guiding blood transfusion. As increasing evidence supports the benefit of limiting transfusion, guidelines have been developed and disseminated into clinical practice governing optimal transfusion of red cells, platelets, plasma and cryoprecipitate. Concepts ranging from transfusion thresholds to prophylactic use to maximal storage time are addressed in guidelines. Patient blood management programs have developed to implement principles of patient safety through limiting transfusion in clinical practice. Data from National Hemovigilance Surveys showing dramatic declines in blood utilization over the past decade demonstrate the practical uptake of current principles guiding patient safety. In parallel with decreasing use of traditional blood products, the development of new technologies for blood transfusion such as freeze drying and cold storage has accelerated. Approaches to policy decision making to augment blood safety have also changed. Drivers of these changes include a deeper understanding of emerging threats and adverse events based on hemovigilance, and an increasing healthcare system expectation to align blood safety decision making with approaches used in other healthcare disciplines.

Transfusion Reactions: A Case Study of an Ocular Adverse Event During Autologous Transplantation

BACKGROUND

Transfusion of blood products is an integral part of hematopoietic stem cell transplantation. Because of the risk for myelotoxicity during conditioning regimens, adequate transfusion support is needed. Typical signs and symptoms of transfusion reactions include fever, chills, hives, and itching. Uncommon symptoms, such as conjunctival erythema, periorbital itching, erythema, and edema, can also occur.

OBJECTIVES

The purpose of this article is to describe atypical transfusion-related reactions in a patient undergoing stem cell transplantation.

METHODS

This article presents a case study of a patient with cancer undergoing autologous stem cell transplantation who experienced an adverse ocular reaction following platelet transfusion.

FINDINGS

Ensuring that oncology nurses are proactive in identifying and managing symptoms that can result from atypical transfusion reactions can reduce morbidity and mortality and improve overall patient care outcomes.

Transfusion Management in Pediatric Oncology Patients

Pediatric oncology patients will likely require numerous transfusions of blood products, including red blood cell, platelet, and plasma transfusions, during the course of their treatment. Although strong evidence-based guidelines for these products in this patient population do not exist, given the morbidities associated with the receipt of blood products, practitioners should attempt to use restrictive transfusion strategies.

A pilot study evaluating the effects of prestorage leukoreduction on markers of inflammation in critically ill dogs receiving a blood transfusion

OBJECTIVES

To compare markers of inflammation after transfusion of leukoreduced (LR) packed RBCs (pRBCs) versus non-LR pRBCs in dogs with critical illness requiring blood transfusion, and to report survival to discharge and rates of transfusion reactions in these dogs.

DESIGN

Prospective randomized blinded clinical study June 2014-September 2015.

SETTING

University veterinary teaching hospital.

ANIMALS

Twenty-three client-owned critically ill dogs, consecutively enrolled.

INTERVENTIONS

Dogs requiring a single pRBC transfusion were randomized into the LR or non-LR pRBC group. Exclusion criteria included: requirement for multiple blood products, history of previous blood transfusion, and administration of anti-inflammatory or immunosuppressive medication prior to enrollment.

MEASUREMENTS

Blood samples were obtained immediately prior to transfusion, then 2 and 24 hours following transfusion. Parameters measured at each time point included: PCV, WBC count, segmented and band neutrophil counts, fibrinogen, and plasma lactate and C-reactive protein concentrations. Acute patient physiologic and laboratory evaluation fast score was calculated on admission.

RESULTS

Eleven dogs were included in the LR group and 12 in the non-LR group; scores of illness severity were not significantly different between groups. Total WBC count was significantly higher in the non-LR versus LR group 24 hours following pRBC transfusion, but this difference was not evident 2 hours following transfusion. No other inflammatory parameters at any time point were significantly different between LR versus non-LR pRBC transfused dogs. Survival rates to discharge for LR and non-LR groups were 8/11 and 9/12, respectively. Acute transfusion reactions were identified in 1/11 and 2/12 dogs in the LR and non-LR group, respectively. All transfused blood was stored ≤12 days.

CONCLUSIONS

Most markers of inflammation did not significantly increase following transfusion of LR versus non-LR pRBCs stored ≤12 days in ill dogs. Further prospective, randomized trials are needed in clinically ill dogs to determine the benefit of prestorage leukoreduction.

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.

Hemostatic properties of cold-stored whole blood leukoreduced using a platelet-sparing versus a non-platelet-sparing filter

BACKGROUND

Whole blood (WB) is an appealing alternative to component-based transfusion in patients with significant bleeding. Historically, WB was transfused less than 48 hours after collection and was not leukoreduced (LR). However, LR components are now standard in many hospitals and LR WB is desirable. We investigated the effect of the type of LR filter used, as well as storage duration, on coagulation laboratory testing of WB.

STUDY DESIGN AND METHODS

Ten units of LR WB-5 units manufactured with a Food and Drug Administration (FDA)-approved platelet (PLT)-sparing filter (WB-PS) and 5 units manufactured with an FDA-approved non-PLT-sparing filter (WB-NPS)-underwent complete blood count, PLT function analyzer (PFA [PFA-100]), thromboelastography (TEG), prothrombin time (PT), partial thromboplastin time (PTT), Factor (F)V activity, chromogenic FVIII, thrombin generation, and microparticle quantification on Storage Days 3, 5, 7, 10, and 14.

RESULTS

WB-PS contains more PLTs than WB-NPS (mean, 71 × 10⁹ /L vs. 1 × 10⁹ /L, p < 0.001). WB-PS yielded essentially normal TEG tracings, while TEG tracings of WB-NPS were grossly abnormal (mean reaction time, 7.0 min for WB-PS vs. 9.7 min for WB-NPS, p < 0.001; mean alpha-angle 54.9° vs. 38.1°, p < 0.001; mean maximum amplitude, 54.9 mm vs. 13.9 mm, p < 0.001). PFA-100 closure was more common among units of WB-PS compared to units of WB-NPS (72% vs. 4%, p < 0.001). PT, PTT, and factor activities were not dramatically affected by the LR filter.

CONCLUSION

The choice LR filter has a major impact on the hemostatic properties of WB. Although storage of WB is associated with a rapid decline in PLT count, hemostasis as assessed by TEG and PFA-100 is not diminished over a 2-week storage period.

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.

Pre-operative autologous blood donation and transfusion-related adverse reactions: A 14-year experience at a university hospital

OBJECTIVE

The objective of this study was to determine the rate of adverse reactions to pre-operative autologous blood donation (PAD) transfusion in a single institution over a 14-year period.

STUDY DESIGN AND METHODS

Between January 2003 and December 2016, we investigated adverse reactions to PAD transfusion and compared them with those to allogeneic blood transfusion in Juntendo University Hospital. Adverse reactions were categorized according to the definition proposed by the International Society of Blood Transfusion (ISBT) Working Party on Haemovigilance.

RESULTS

A total of 178,014 blood components were transfused during the study period, of which PAD transfusions were 13,653 (8%), whereas allogeneic blood transfusions were 164,361 (92%). The number and rate of adverse reactions to PAD transfusion were 16 and 0.1%, whereas those of allogeneic blood transfusion were 1075 and 0.7%, respectively. The rate of adverse reactions to allogeneic blood transfusions excluding platelet transfusion was 0.3%, being significant (p < 0.01) against PAD transfusion. Among 16 adverse reactions to PAD transfusion, the most common was febrile non-hemolytic transfusion reaction (FNHTR) at 12 (75%), followed by allergic reaction at 4 (25%). The severity of adverse reactions to PAD transfusion was Grade 1 (non-severe) in all cases. With regard to blood component types, 16 adverse reactions involved: 12 cases of whole blood PAD, 2 of frozen PAD, and 2 of autologous fresh-frozen plasma.

CONCLUSIONS

Non-severe adverse reactions were observed on PAD transfusion at a rate of 0.1% at our institution.

Fatal massive hemolysis caused by immunoglobulin M anti-c antibody in a patient with newly diagnosed B-cell acute lymphoblastic leukemia: a case report

Delayed hemolytic transfusion reactions (DHTRs) occur secondary to slow, mild IgG-mediated processes against minor red blood cell antigens. Herein, we report the case of a rapidly fatal alloimmune anti-c IgM-mediated hemolysis, a rare, previously undescribed, pathophysiologic scenario. Early recognition of such phenomena can expedite supportive measures and optimize patient outcomes.

Interleukin-8, interleukin-1β and tumour necrosis factor-α in sequential units of packed red blood cells collected from retired racing Greyhounds

BACKGROUND

We hypothesised that concentrations of interleukin-8 (IL-8), interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) would increase during storage in the third sequential unit (U3) of canine packed red blood cells (PRBC) collected from terminal donors in haemorrhagic shock. We further hypothesised that leucoreduction would prevent cytokine accumulation in U3 and that cytokine concentrations in U3 would be higher than in the first units (U1) collected from the same dogs.

METHODS

U1 and U3 were each collected from 12 anaesthetised healthy Greyhounds. Removal of leucocytes from half of each PRBC unit produced one leucoreduced (LR) and one non-leucoreduced (NLR) unit. Canine IL-8, IL-1β and TNF-α concentrations were measured in samples collected from the units during storage on days 0, 10, 20, 30 and 37.

RESULTS

The IL-8 concentration in U3 NLR units was significantly higher on days 10, 20, 30 and 37 than on day 0 and was significantly higher than in the LR units at all time points. The IL-1β concentration in U3 did not change over time, or between LR and NLR units. TNF-α was not detected in any unit. There were no significant differences in IL-8 or IL-1β concentrations between U3 and U1 at any time point; however, some NLR U3 units had markedly elevated IL-8 concentrations at day 37 (2060-20,682 pg/mL) compared with NLR U1 units (3369-5280 pg/mL).

CONCLUSION

NLR U3 units collected from dogs in haemorrhagic shock showed a significant increase in IL-8 concentrations during storage. Leucoreduction was effective at preventing the accumulation of IL-8. There was no difference detected between U3 and U1.

A multicentre study investigating vital sign changes occurring in complicated and uncomplicated transfusions

BACKGROUND AND OBJECTIVES

Many hospitals require transfusions to be discontinued when vital signs stray from predetermined ranges, regardless of clinical symptoms. Variations in vital signs may be unrelated to transfusion, however, and needlessly stopping a transfusion may delay medical care while increasing donor exposures and healthcare costs. We hypothesized that a detailed study of vital sign changes associated with transfusion of blood product by component, including those associated with potential reactions (complicated) and those deemed to be uncomplicated, would establish a useful framework of reference for treating clinicians and transfusion services alike.

MATERIALS AND METHODS

A retrospective electronic record review of transfusion service and transfusion recipient data was completed on 3852 inpatient transfusion episodes over a 6-month period at four academic tertiary care hospitals across the United States. Vital signs pre- and post-transfusion were recorded by trained clinical research nurses. Serious reactions were adjudicated by a panel of transfusion medicine experts.

RESULTS

In both uncomplicated transfusions (n = 3765) and those including an adverse reaction (n = 87), vital sign fluctuations were generally modest. Compared to uncomplicated transfusions, transfusions complicated by febrile reactions were associated with higher pretransfusion temperature and higher pretransfusion pulse rates. Episodes of transfusion circulatory overload were associated with higher pretransfusion respiration rates compared to uncomplicated transfusions.

CONCLUSION

Most transfusions are associated with only modest changes in vital signs. Pretransfusion vital signs may be an important yet previously understudied predictor of vital sign changes during transfusion. The optimal role of vital sign assessment during blood transfusion deserves further study.

Transfusion-associated adverse reactions (TAARs) and cytokine accumulations in the stored blood components: the impact of prestorage versus poststorage leukoreduction

Leukoreduction in blood units could prevent patients undergoing transfusions from transfusion-associated adverse reactions (TAARs) such as febrile nonhemolytic transfusion reactions (FNHTRs). However, the effect of prestorage and poststorage leukoreduction on TAARs and its underlying mechanisms in stored blood components remains to be determined. Therefore, we investigated the impact of prestorage leukocyte-reduced (pre-LR) and poststorage leukocyte-reduced (post-LR) blood products, including red blood cells (RBCs) and apheresis platelets (PHs), on the incidence of FNHTRs and other TAARs in patients who received transfusions from 2009 to 2014 in a tertiary care center. We also investigated the difference of leukocyte-related bioactive mediators between pre- and post-LR blood components. The results indicated that prevalence of TAARs was significantly reduced in the transfusions of pre-LR blood components. Particularly, the prevalence of FNHTRs was significantly reduced in the pre-LR RBC transfusions and the prevalence of allergy reactions was markedly reduced in the pre-LR PH transfusions. Furthermore, in vitro evaluation of cytokines in the pre- and post-LR blood components revealed that IL-1β, IL-8 and RANTES levels were significantly elevated in the post-LR RBCs during the storage. In contrast, IL-1β, IL-6 and IL-8 levels were significantly elevated in the post-LR PHs during the storage. These findings suggested that prestorage leukoreduction had a diminishing effect on the development of TAARs, which could be associated with less accumulation of cytokines in the stored blood components.

Changes in circulating inflammatory markers following febrile non-haemolytic transfusion reactions to leucoreduced red cells

It would be desirable to be able to distinguish fever as a result of febrile non-haemolytic transfusion reactions (FNHTR) from other febrile conditions. To further characterize the inflammatory feature of FNHTR, we measured a large panel of inflammatory markers in pre- and posttransfusion plasma samples from patients with and without FNHTR following the transfusion of leucoreduced red blood cells. As FNHTR patients only displayed a significant increase in IL-6, we conclude that changes in plasma cytokine levels during FNHTR are unlikely to be used diagnostically. An incidental finding of a distinct cytokine pattern in pretransfusion samples from FNHTR patients warrants further investigations, as it might be used to characterize the nature of FNHTR and to predict the risk of these adverse events.

Adverse Reactions to Transfusion of Blood Products and Best Practices for Prevention

Transfusion, a common practice in critical care, is not without complication. Acute adverse reactions to transfusion occur within 24 hours and include acute hemolytic transfusion reaction, febrile nonhemolytic transfusion reaction, allergic and anaphylactic reactions, and transfusion-related acute lung injury, transfusion-related infection or sepsis, and transfusion-associated circulatory overload. Delayed transfusion adverse reactions develop 48 hours or more after transfusion and include erythrocyte and platelet alloimmunization, delayed hemolytic transfusion reactions, posttransfusion purpura, transfusion-related immunomodulation, transfusion-associated graft versus host disease, and, with long-term transfusion, iron overload. Clinical strategies may reduce the likelihood of reactions and improve patient outcomes.

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.

Feeling the burn: the significant burden of febrile nonhemolytic transfusion reactions

BACKGROUND

Febrile nonhemolytic transfusion reactions (FNHTRs) are characterized by a post-transfusion temperature rise (of ≥ 1°C, to ≥ 38°C) or chills/rigors unrelated to the underlying condition. FNHTRs are provoked by inflammatory cytokines in the product or by host antileukocyte antibodies against residual donor leukocytes. FNHTRs are among the most commonly reported transfusion disturbances and are generally deemed nonserious events. However, their impact on patients and hospitals may be underestimated.

STUDY DESIGN AND METHODS

A search through two hemovigilance databases identified all known possible-to-definite FNHTRs over 3 years (2013-2015) at four academic hospitals using prestorage leukoreduced components. FNHTRs were assessed for frequency by product (red blood cells [RBCs], platelets [PLTs], intravenous immunoglobulin), diagnostics (bedside, chest imaging, serology, microbiology), and management (medications, disposition change). The definition of FNHTR was derived from Canada's Transfusion-Transmitted Injuries Surveillance System.

RESULTS

For 437 FNHTRs, the overall per-product rate across all sites was 0.24%, or 0.17% with RBCs alone and 0.25% with PLTs alone. One-third of patients had significant fevers (≥ 39.0°C or a rise by ≥ 2.0°C). Approximately one-quarter underwent chest imaging within 48 hours, and 79% had blood cultures. A hospital admission directly attributable to the FNHTR, to exclude other causes of fever, occurred in 15% of FNHTR outpatients.

CONCLUSION

An analysis of FNHTRs reveals a substantial burden of postreaction clinical activity in addition to the disturbance itself. Efforts to avoid this adverse event may save resources, reduce patient distress, and encourage compliance with more restrictive transfusion strategies.