Transfusion of platelets containing ABO-incompatible plasma: a survey of 3156 North American laboratories

Transfusion outcomes and clinical safety of ABO-nonidentical platelets transfusion: A systematic review and meta-analysis

BACKGROUND

ABO-nonidentical platelets transfusion has been frequently employed to address clinical platelets insufficiencies. The significance of ABO compatibility for platelets transfusion is not clearly defined. This study is aimed to explore the transfusion outcomes and clinical safety of ABO-nonidentical platelets transfusion.

STUDY DESIGN AND METHODS

A systematic articles search was performed for eligible studies published up to November 30, 2023 through the PubMed, Embase, Cochrane library, Chinese National Knowledge Infrastructure database, Wanfang database and SinMed. Meta-analysis Of Observational Studies in Epidemiology study guidelines for observational studies and Newcastle Ottawa bias scale were implemented to assess studies. Meta-analysis was performed using Manager 5.3. This study is registered with PROSPERO, number CRD42023417824.

RESULTS

A total of 11 retrospective cohort studies and 7 prospective cohort studies with a sample size of 104,359 platelets transfusions were included. There was significant difference in transfusion effectiveness between the ABO-identical and ABO-nonidentical platelets transfusions (RR 1.20, 95 % CI 1.11-1.38, P < 0.00001, I2 = 21 %), also the ABO-identical platelets transfusions showed more platelets increment than ABO-nonidentical ones, but it was not statistically significant (MD 0.34, 95 % CI - 0.01 to 0.70, P = 0.06, I2 = 0 %). Allergy and fever occurred more in ABO-nonidentical platelets transfusions in terms of adverse reactions (RR 0.63, 95 % CI 0.41-0.96, P = 0.03, I2 = 0 %; RR 0.59, 95 % CI 0.37-0.94, P = 0.03, I2 = 31 %). When it comes to the mortality, the ABO-identical platelets transfusions did not statistically improve survival in patients who received multiple platelets transfusions (RR 0.77, 95 % CI 0.72-0.83, P = 0.17, I2 = 38 %) and who only received less than 3 transfusions (RR 0.74, 95 % CI 0.52-1.06, P = 0.10, I2 = 47 %) compared with the ABO-nonidentical platelets transfusions.

CONCLUSION

In comparison to ABO-identical platelets transfusions, nonidentical platelets transfusions exhibited lower transfusion efficacy. However, the clinical safety between these two groups was similar, which indicated that ABO-nonidentical transfusions are acceptable, albeit inferior to ABO-identical ones.

Isohemagglutinin titration in pooled and apheresis platelets

BACKGROUND

Platelet inventory constraints necessitate ABO-incompatible platelet transfusion. Many minimize the hemolytic impact by confirming low titre (LT) donor isohemagglutinins. This process is costly. Pathogen-reduced platelets (PRP) in platelet additive solutions (PAS) will dilute plasma and decrease high-titre isohemagglutinins (HT). We determined the proportion of HT platelets and incompatible transfusions for units suspended in plasma to reassess the need for titres following introduction of PRP/PAS.

STUDY DESIGN AND METHODS

Our titre method is manual tube (1:50) dilution of platelet supernatant from apheresis or whole blood derived buffy coat pools suspended in plasma, tested with A1/B red cells. Testing included 49,058 pooled and 11,738 apheresis platelets over 4 years. The HT proportion, rate of out-of-group transfusions, and hemolytic reactions were determined. The impact of PAS dilution was estimated.

RESULTS

Totally 60,796 platelet units were tested. Group O pooled and group B apheresis platelets had HT in 6.6% and 5.7%, respectively. Group A pooled and apheresis platelets included 2% with HT. Approximately 25% of platelets transfused were ABO-incompatible and no hemolytic reactions were reported. Based on the proportions of PAS-E and plasma for PRP platelets, plasma from each donor comprises 11 mL (6% of total volume) vs 20-257 mL in untreated pools. PAS-E will replace and dilute residual plasma by at least 50%.

DISCUSSION

Rare platelet pools may demonstrate HT. PRP platelets with PAS will reduce titres and may abrogate the need for titration. A strategy of group specific transfusion or transfusion of group A PRP platelet transfusions may be a safe alternative.

Antibody Titers in Transfusion Medicine: A Critical Reevaluation of Testing Accuracy, Reliability, and Clinical Use

CONTEXT.—

Substantial variability between different antibody titration methods has been identified since the development and introduction of the uniform procedure in 2008.

OBJECTIVE.—

To determine whether more recent methods or techniques decrease interlaboratory and intralaboratory variation measured using proficiency testing.

DESIGN.—

Proficiency test data for antibody titration between 2014 and 2018 were obtained from the College of American Pathologists. Interlaboratory and intralaboratory variations were compared by analyzing the distribution of titer results by method and phase, comparing the results against the supplier's quality control titer, and by evaluating the distribution of paired titer results when each laboratory received a sample with the same titer twice.

RESULTS.—

A total of 1337 laboratories participated in the antibody titer proficiency test during the study period. Only 54.1% (5874 of 10 852) of anti-D and 63.4% (3603 of 5680) of anti-A reported responses were within 1 titer of the supplier's intended result. Review of the agreement between laboratories of the same methodology found that 78.4% (3139 of 4004) for anti-A and 89.0% (9655 of 10 852) of laboratory responses for anti-D fell within 1 titer of the mode response. When provided with 2 consecutive samples of the same titer (anti-D titer: 16), 85% (367 of 434) of laboratories using the uniform procedure and 80% (458 of 576) using the other method reported a titer difference of 1 or less.

CONCLUSIONS.—

Despite advances, interlaboratory and intralaboratory variance for this assay remains high in comparison with the strong reliance on titer results in clinical practice. There needs to be a reevaluation of the role of this test in clinical decision-making.

Hemolysis in reverse grouping: Evaluation and implication of high titer isoagglutinin of two blood donors

Hemolysis is a positive agglutination reaction and is primarily associated with high anti-A or anti-B antibody titers. This high titer may result in no agglutination due to the "prozone" phenomenon. Platelet concentrate of high titer has an adverse effect on the recipient of the non-identical ABO blood group. Similarly, the blood products with higher titers of isoagglutinin have recently increased the incidence of intravenous immunoglobulins-related hemolysis. In this Asian subcontinent, the impact of O blood donors with high antibody titers or ABO incompatible platelets is hardly addressed. Blood was collected from two healthy donors and subjected to blood grouping as done routinely. Hemolysis was observed in the reverse grouping with the "B-"cell. Blood grouping was repeated with the conventional tube technique (CTT) where there was no agglutination with the "B"-cell. Suspecting the "prozone" phenomenon, serial dilution of anti-B was done by CTT, and the titer was found to be 1:256 and 1:128 in both cases. Then, the reverse grouping was repeated with a diluted serum (1:8), and the blood group was confirmed to be A RhD-positive and O RhD-positive, respectively. The absence of agglutination in a reverse grouping is not only an indicator of weak antibody but also a presentation of the "prozone" phenomenon. This could be differentiated by doing the titer of isoagglutinin. Hemolysis due to high agglutinin levels should be documented and evaluated, and blood components should be properly labeled to ensure that the product is transfused to the same blood group patients.

ABO blood group antigens and differential glycan expression: Perspective on the evolution of common human enzyme deficiencies

Enzymes catalyze biochemical reactions and play critical roles in human health and disease. Enzyme variants and deficiencies can lead to variable expression of glycans, which can affect physiology, influence predilection for disease, and/or directly contribute to disease pathogenesis. Although certain well-characterized enzyme deficiencies result in overt disease, some of the most common enzyme deficiencies in humans form the basis of blood groups. These carbohydrate blood groups impact fundamental areas of clinical medicine, including the risk of infection and severity of infectious disease, bleeding risk, transfusion medicine, and tissue/organ transplantation. In this review, we examine the enzymes responsible for carbohydrate-based blood group antigen biosynthesis and their expression within the human population. We also consider the evolutionary selective pressures, e.g. malaria, that may account for the variation in carbohydrate structures and the implications of this biology for human disease.

Severe acute haemolytic transfusion reaction secondary to a plasma incompatible group B platelet transfusion

OBJECTIVES

To report a rare case of acute hemolytic transfusion reaction (AHTR) following an ABO plasma incompatible group B platelet transfusion.

BACKGROUND

AHTR is an uncommon, but potentially fatal event. Most reported cases of platelet transfusions associated with AHTR involve group O donors.

CASE REPORT

A 34-year-old man, recipient of a group AB haploidentical haematopoietic stem cell transplantation (HSCT), had received re-induction chemotherapy for leukaemia relapse. A group B whole blood-derived buffy coat platelet pool was transfused. He developed rigours/fever, profound hemolytic anaemia, and hemodynamic instability. Serological investigations revealed AHTR from passive transfer of high titre anti-A (256 for IgM and 8192 for IgG).

DISCUSSION

This case highlights the potential risks associated with ABO-mismatched transfusions, and the complexity associated with transfusing HSCT recipients and red cell transfusion recipients with dual populations of circulating red cells. The literature on minor ABO plasma incompatible transfusions, challenges in establishing local policies to limit the risks of AHTR and risk mitigation strategies are discussed.

CONCLUSION

Clinicians must maintain a high level of suspicion for AHTR after ABO plasma incompatible platelet transfusions. Patients must be aware of the risks of AHTR, and early recognition and diagnosis of this complication may be lifesaving.

Platelet additive solution suspended apheresis platelets in a tertiary care hospital: A step toward universal single donor platelets

BACKGROUND

Transfusion of ABO-compatible single donor platelets (SDP) is preferable for better outcomes over group switchover SDP. The use of SDP containing ABO-incompatible plasma is associated with a risk of allergic and acute hemolytic transfusion reactions. Moreover, high titer O group donors SDP impose a further threat to patient safety. Platelet additive solution (PAS) is used worldwide for the storage of platelets which reduces plasma volume available in SDP. SSP + (Macopharma) is one such PAS which can provide improved availability, logistical management, decrease wastage, and improvement in patient safety. The aim of this study was to assess the feasibility of using PAS to obtain low titer SDP units which can be utilized across a larger patient population and to study quality control parameters of these units.

MATERIALS AND METHODS

The study was performed in the department of Transfusion Medicine from June 2017 to January 2018 after clearance from the Institutional Review Board. The study design comprised two cohorts (A and B). In cohort A, the temporal trend of in-vitro changes in the quality parameters was tested and analyzed for PAS modified and unmodified products on days 1, 5 and 7. In cohort B, the original plasma from the SDP donors of all blood group donors except the AB group was tested for antibody titers before (prepreparation) and after modification (postpreparation) by PAS.

RESULTS

In cohort A, in the control group, there was a significant change in the mean platelet volume, potassium, and bicarbonate levels from day 1 to day 7, whereas no significant change in the biochemical parameters was noted in the study group where PAS was used. In cohort B, on comparing the anti-A and anti-B, before and after modification of SDP with PAS, there was a significant reduction in the median titers across all the groups studied.

CONCLUSION

PAS added SDP is an efficient strategy to reduce the ABO-antibody levels significantly. PAS added SDP also helps in the better inventory management of available groups.

High titers of anti-A1 and anti-B antibodies among Peruvian group O platelet donors

Critical antibody titers have been described as factors associated with hemolysis in ABO plasma-incompatible platelet (PLT) transfusions. This study was carried out to describe the frequency of high-titers anti-A and antiB IgM and IgG antibodies in group O apheresis platelet donors, and to explore differences according to the donor characteristics. A cross-sectional study was carried out at the Blood Bank of a National Hospital in Peru from January to March 2019. IgM and IgG antibodies against A1 and B antigens were quantified in 339 platelet donors using the direct hemagglutination technique and the solid-phase adherence technique, respectively. For analysis purposes, two cut-off points; ≥128 and ≥64, were used to define a critical titer for IgM due to a lack of consensus. An IgG titer of ≥256 was also defined as critical. Of the donors, 22.1 % had critical IgM titers when the cut-off point was defined as ≥128. However, when the IgM cut-off was ≥64, the frequency of platelet donors with critical titers increased to 54.0 %. The frequency of donors with critical IgG titers was 23.5 %. Higher IgG titers were associated with female donors while higher IgM titers were negative associated with age. One in two or three platelet donors, depending on the cutoff point used to define a critical IgM titer, had at least one critical titer of anti-A or anti-B antibodies. Early identification of platelet donors with critical antibody titers could prevent passive transfusion of ABO antibodies to non-isogroup recipients.

ABO antibody titer performance characteristics and correlates between two automated platforms

BACKGROUND

AABB standards require a policy for assessing transfusing ABO-incompatible plasma. After a fatal hemolytic event with incompatible plasma, our institution instituted platelet donor population titer method for ABO antibodies on the PK7300, with high-titer being defined as having isohemagglutinin titers greater than 256. We recently switched titering platforms to the Neo Iris and we seek to determine the equivalent isohemagglutinin high-titer cutoff on the Neo Iris as compared to the PK7300.

METHODS

We measured the titers on 299 apheresis platelet donors and compared its performance characteristics at various cutoffs to the PK7300 reference standard. Discrepant results were manually diluted and retested on the Neo Galileo. Furthermore, since the Neo Iris is able to determine isotype and antigen specific titers, we also characterized these features in our donor population.

RESULTS

IgM titer of 128 on the Neo Iris has better accuracy compared to the titer of 64 (94 % vs 93.6 %). Eleven of sixteen discordant results were in agreement with Neo Iris. Blood group O had the highest IgG antibody titers for both anti-A and anti-B (p = 8.4E-17 and 4.3E-09, respectively). Additionally, group O donors exhibited lower anti-A2 than anti-A1 IgG titers.

DISCUSSION

The Neo Iris titer cut-off of 128 had the best overall accuracy and correlation with a 256 cut-off on our laboratory developed test on the PK7300 platform. Additionally, we found that group O donors had the highest titer antibodies, with typically higher IgG titers than IgM, and generally multiple dilution levels greater than other blood types.

Does ABO and RhD matching matter for platelet transfusion?

Platelets express ABO antigens and are collected in plasma, which contains ABO antibodies as would be consistent with the donor ABO group. Platelet ABO antigens that are incompatible with recipient ABO antibodies may have accelerated clearance from circulation and result in lower count increments. ABO antibodies that are passively transferred from donor plasma may result in hemolysis of recipient red blood cells. Although platelets do not express Rh antigens, they contain small numbers of intact red blood cells or fragments, which can lead to alloimmunization in the recipient. Alloimmunization to the RhD antigen may occur when platelets obtained from RhD-positive donors are transfused to RhD-negative recipients. All of these compatibility considerations must be balanced against the available supply, which may be limited due to the 5- to 7-day shelf life of platelets. This articles describes considerations for platelet ABO and RhD selection for platelet transfusions, including the impact of major ABO incompatibility on count increments, the risks of hemolysis associated with minor ABO incompatibility, and the risk of RhD alloimmunization when RhD-negative patients receive platelets obtained from RhD-positive donors.

Multifaceted role of glycosylation in transfusion medicine, platelets, and red blood cells

Glycosylation is highly prevalent, and also one of the most complex and varied posttranslational modifications. This large glycan diversity results in a wide range of biological functions. Functional diversity includes protein degradation, protein clearance, cell trafficking, cell signaling, host-pathogen interactions, and immune defense, including both innate and acquired immunity. Glycan-based ABO(H) antigens are critical in providing compatible products in the setting of transfusion and organ transplantation. However, evidence also suggests that ABO expression may influence cardiovascular disease, thrombosis, and hemostasis disorders, including alterations in platelet function and von Willebrand factor blood levels. Glycans also regulate immune and hemostasis function beyond ABO(H) antigens. Mutations in glycogenes (PIGA, COSMC) lead to serious blood disorders, including Tn syndrome associated with hyperagglutination, hemolysis, and thrombocytopenia. Alterations in genes responsible for sialic acids (Sia) synthesis (GNE) and UDP-galactose (GALE) and lactosamine (LacNAc) (B4GALT1) profoundly affect circulating platelet counts. Desialylation (removal of Sia) is affected by human and pathogenic neuraminidases. This review addresses the role of glycans in transfusion medicine, hemostasis and thrombosis, and red blood cell and platelet survival.

Comparison of abo antibody levels in apheresis platelets suspended in platelet additive solution and plasma

Background

Transfusion of platelets (PLTs) with high ABO antibody titres can pose a risk of hemolysis if the unit crosses the ABO type. The PLTs stored in the platelet additive solution (PAS) remove asubstantial fraction of plasma and replace it with an isotonicbuffered solution.We aimed to assess the difference in anti-A/B antibody levels in Groups O, A and B apheresis platelets (APs) suspended in plasma and PAS.

Methodology

Apheresis donors are categorized into two groups, Plasma (Group I) and PAS (Group II), each blood group (A, B and O) had 20 samples. The anti-A/B(IgM)antibody levels were recorded from the AP donor (Group II) and from the AP units for both groups. The reduction in the anti-A/B(IgM) antibody levels in the APs suspended in the PAS for each blood group was determined.

Results

The median anti-A titres in blood Groups B (p = 0.009) and O (p = 0.005) was significantly lower in Group II. However, the difference in anti-B levels was not significant in the blood groups A (p = 0.057) and O (p = 0.205). The median level of reduction in IgM antibody titres across donor samples and the PAS-stored platelets was two-fold. The regression showed a level of reduction in antibody titres which can be explained by baseline donor antibody titres in blood groups A and B compared to blood group O.

Conclusion

The medianABO antibody titres were lower in APs suspended in PAS than in plasma. Addition of the PAS significantly lowered the IgM antibody titres by twofold, compared to plasma.

Comparison of ABO antibody titration, IgG subclasses and qualitative haemolysin test to reduce the risk of passive haemolysis associated with platelet transfusion

BACKGROUND

One of the strategies used to reduce the risk of haemolysis due to ABO-minor incompatible platelet transfusions is to perform a screening test to identify group O donors with high titres of anti-A and anti-B. However, critical immunoglobulin M/ immunoglobulin G (IgM/IgG) titres remain unclear.

OBJECTIVE

This study aimed to determine IgM titres of anti-A and anti-B in individual donor serum vs platelet products plasma and identify a possible association between IgM/IgG titres, haemolysin test and IgG subclasses in Brazilian blood donors from group O.

METHODS

IgM anti-A and Anti-B titration tests were performed on single-donor serum and platelet product plasma by gel agglutination (GA) at room temperature. For IgG anti-A and anti-B titration, serum was first treated with 0.01 M dithiothreitol (DTT), and the test was performed by GA with incubation at 37°C. Dilution of 1:64 as the cut-off was considered for both IgM/IgG. The qualitative haemolysin test was performed in tube, adding AB fresh serum, with incubation at 37°C. IgG subclasses were determined by GA using specific monoclonal antibodies.

RESULTS

An association between anti-A and anti-B IgM titres and haemolysin were demonstrated (P < .001). IgM titres in plasma samples from platelet components correlated to those in single-serum samples. IgG1/IgG3 subclasses were associated with total haemolysis and titres above 64, whereas IgG2/IgG4 subclasses were associated with the absence of haemolysis and titres below 64 (P < .001).

CONCLUSION

Our data suggest that a value of 64 as a critical titre can be used as a screening test of anti-A and anti-B IgM to prevent transfusion reactions. This can be a safe and cost-effective approach for managing ABO-incompatible platelet transfusions.

Complement activating ABO anti-A IgM/IgG act synergistically to cause erythrophagocytosis: implications among minor ABO incompatible transfusions

BACKGROUND

Typically minor ABO incompatible platelet products are transfused without any incident, yet serious hemolytic transfusion reactions occur. To mitigate these events, ABO 'low titer' products are used for minor ABO incompatible transfusions. We sought to understand the role of IgM/IgG and complement activation by anti-A on extravascular hemolysis.

METHODS

Samples evaluated included (i) Group O plasma from a blood donor whose apheresis platelet product resulted in an extravascular transfusion reaction, (ii) Group O plasma from 12 healthy donors with matching titers that activated complement (N = 6) or not (N = 6), and (iii) Group O sera from 10 patients with anti-A hemolysin activity. A flow cytometric monocyte erythrophagocytosis assay was developed using monocytes isolated by immunomagnetic CD14-positive selection from ACD whole blood of healthy donors. Monocytes were frozen at - 80 °C in 10% dimethyl sulfoxide/FBS and then thawed/reconstituted on the day of use. Monocytes were co-incubated with anti-A-sensitized fluorescently-labeled Group A1 + RBCs with and without fresh Group A serum as a source of complement C3, and erythrophagocytosis was analyzed by flow cytometry. The dependency of IgM/IgG anti-A and complement C3 activation for RBC erythrophagocytosis was studied. Anti-A IgG subclass specificities were examined for specific samples.

RESULTS

The plasma and sera had variable direct agglutinating (IgM) and indirect (IgG) titers. None of 12 selected samples showed monocyte-dependent erythrophagocytosis with or without complement activation. The donor sample causing a hemolytic transfusion reaction and 2 of the 10 patient sera with hemolysin activity showed significant erythrophagocytosis (> 10%) only when complement C3 was activated. The single donor plasma and two sera demonstrating significant erythrophagocytosis had high IgM (≥ 128) and IgG titers (> 1024). The donor plasma anti-A was IgG1, while the patient sera were an IgG3 and an IgG1 plus IgG2.

CONCLUSION

High anti-A IgM/IgG titers act synergistically to cause significant monocyte erythrophagocytosis by activating complement C3, thus engaging both Fcγ- and CR1-receptors.

Differences in donor compatibility for fresh and freeze-dried homologous platelet rich plasma studied using crossmatch test

Platelet-rich plasma (PRP) rich in growth factors has evolved as an important therapy for periodontal tissue regeneration. A healthy blood donors obtained for homologous PRP (h-PRP). The Freeze-drying h-PRP sample provides an effective method to ensure a longer shelf-life. The h-PRP samples are subjected to crossmatch testing in clinics to prevent any immune response in recipients. The present study aimed to evaluate the differences in donor compatibility on crossmatch test results towards fresh and freeze-dried h-PRP (FD h-PRP). This was a laboratory experiment, h-PRP prepared according to the protocol of blood bank, and 40 recipients blood samples divided into two groups, fresh h-PRP (control group) and FD h-PRP. The crossmatch test was performed to evaluate h-PRP compatibilities by using the gel-test method. The data were analyzed using the chi-square test. The results of the study showed that the crossmatch test on FD h-PRP samples was 100 % compatible and could increase the compatibility results of the donor. the FD h-PRP was safe to become donors and clinical applications.

Fatal acute hemolytic transfusion reaction due to anti-B from a platelet apheresis unit stored in platelet additive solution

BACKGROUND

Hemolytic transfusion reactions from out-of-group plasma in platelet (PLT) transfusions are uncommon, with most involving passive transfer of anti-A. Only rare reactions have ever been reported due to anti-B.

STUDY DESIGN AND METHODS

An apheresis PLT product was donated by a blood group O male, processed using PLT additive solution, and pathogen reduced. Postreaction recipient testing included an antibody screen using gel technology, a direct antiglobulin test (DAT) using immunoglobulin G and C3, and an eluate against group O and B cells. Postreaction donor testing included measuring anti-B titers in saline, with and without anti-human globulin.

RESULTS

A 60-year-old blood group B patient with relapsed acute myeloid leukemia developed confusion, fever, and hypotension within hours after a blood group O PLT transfusion. The posttransfusion reaction evaluation was remarkable for a positive DAT 3+ for C3; the eluate showed anti-B. Rapid extravascular hemolysis occurred, with a 50% decline in hemoglobin, a high lactate dehydrogenase, and a high bilirubin. She was resuscitated with fluids, blood products, pressors, and oxygen and died of asystole 60 hours later. The donor's anti-B titers were 128 by tube testing at immediate spin and 512 at the anti-human globulin phase. Notably, a group B patient at a different hospital received a split of the same apheresis unit, with no reaction.

CONCLUSION

To our knowledge, this is the first fatality reported from passively transfused anti-B. The fact that one transfusion recipient died whereas another did not have any reported reaction highlights the potential importance of recipient variables in isohemagglutinin-mediated hemolysis.

Acute Hemolytic Transfusion Reaction in Group B Recipient Associated with Group A Apheresis Platelet Donor: Case Report and Literature Review

Acute hemolytic transfusion reaction is a known but rare potential adverse event related to platelet transfusion. Most reported cases of platelet-related hemolytic transfusion reaction have resulted from transfusion of platelets from group O donor to group A recipient. We identified only one prior case report in the literature of hemolytic transfusion reactions resulting from transfusion of apheresis platelets from group A donor to group B recipient. In that case report, two platelet units were obtained from a single donation and transfused into two separate patients. Both patients exhibited acute hemolytic reactions. The donor is reported to have high anti-B titers, as well as report of probiotic use. We report a case of acute hemolytic reaction in group B recipient following transfusion of apheresis platelets from group A donor with high-titer anti-B but unknown status of probiotic use. This case demonstrates that while low, there still exists potential risk for hemolysis from out-of-group A plasma transfusion.

First Indian initiative for preparation of low-titer group "O" single-donor platelets with platelet additive solution

BACKGROUND

Guidelines recommend ABO-identical platelet (PLT) transfusions. Hemolytic reactions after a minor ABO-incompatible PLT transfusion have escalated due to single-donor platelets (SDP) containing ABO-incompatible plasma. Avoiding such events by examining titers or performing plasma reduction is cumbersome. The introduction of platelet additive solutions (PAS) has enabled to reduce these reactions by avoiding passive transfer of isoagglutinin. Our aim was to study antibody titers (anti-A, anti-B) in "O" SDP by adding PAS at source and the quality parameters with reference to viability, morphology, and metabolism.

MATERIALS AND METHODS

Group "O" SDP (n = 50) were prepared on a standard cell separator. PAS in a ratio of 70:30 (PAS: plasma) was added at source under sterile conditions (study arm). The units were studied on day of collection (day 0) and day 4 and compared with SDP containing 100% plasma (control arm). A titer study was performed after PAS addition.

RESULTS

In the study group, the median antibody titers (anti-A, anti-B) reduced from 128 to16, post-PAS addition (P < 0.001). Morphology scores were superior in PAS platelet concentrates (P < 0.001). Metabolic parameters pO2 and pCO2 were similar in the two arms signifying good unit storage and stable oxygen consumption (P > 0.05). Lactate levels, glucose consumption rate, and lactate production rates were significantly low in study arm showing the advantage of PAS.

CONCLUSION

O group SDPs can be prepared with PAS and the beneficial effects were significant with respect to antibody titers. Quality parameters were well maintained. Availability of PAS units has benefitted patients.

Potential impact of complement regulator deficiencies on hemolytic reactions due to minor ABO-mismatched transfusions

Minor ABO-mismatched transfusions are a common occurrence, although infrequent transfusion reactions occur. We sought to investigate the regulation of complement C3 activation induced by anti-A. In vitro complement C3 activation was observed with 10 of 30 group O samples and correlated with immunoglobulin M (IgM) anti-A titers. We developed an in vitro paroxysmal nocturnal hemoglobinuria (PNH) model of hemolysis in which group A1 red blood cells (RBCs) were chemically treated with 2-aminoethylisothiouronium (AET) to alter regulators of complement C3 activation. Intravascular hemolysis was simulated by incubating an IgG nonhemolytic group O plasma (titer = 32) with A1 RBCs. IgG was detected on the RBCs, but hemolysis was observed with AET-treated RBCs only. When treated and untreated RBCs were tested together (1:4), we determined that the failure to observe C3b/d deposition on RBCs was due to the complete hemolysis of the AET-treated minor RBC population. A group O patient with a 9% CD59-deficient PNH clone was sensitized with an IgM anti-I. Hemolysis, with a weak positive direct antiglobulin test (DAT) resulting from C3b/d, was observed after incubation with fresh AB serum. Flow cytometry showed an 86% reduction of the PNH clone. Our work indicates that the transfusion of minor ABO-mismatched plasma could cause hemolysis with a negative DAT C3b/d. We propose that the presence of a PNH clone is 1 possible cause of unexplained anemia for recipients of ABO-mismatched product. This work suggests that other acquired or inherited defects of decay-accelerating factor and membrane inhibitor of reactive lysis could be responsible for infrequent but clinically important hemolysis after ABO-mismatched transfusions.

Consensus Report by the Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplant Consortium Joint Working Committees on Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents: Part 2-Focus on Ascites, Fluid and Electrolytes, Renal, and Transfusion Issues

Even though hepatic veno-occlusive disease (VOD) is a potentially fatal complication of hematopoietic cell transplantation (HCT), there is paucity of research on the management of associated multiorgan dysfunction. To help provide standardized care for the management of these patients, the HCT Subgroup of the Pediatric Acute Lung Injury and Sepsis Investigators and the Supportive Care Committee of the Pediatric Blood and Marrow Transplant Consortium, collaborated to develop evidence-based consensus guidelines. After conducting an extensive literature search, in part 2 of this series we discuss the management of fluids and electrolytes, renal dysfunction; ascites, pleural effusion, and transfusion and coagulopathy issues in patients with VOD. We consider the available evidence using the GRADE criteria.

Antibody titers in Group O platelet donors

BACKGROUND AND OBJECTIVES

The occurrence of hemolysis due to transfusion of ABO plasma-incompatible platelets (PLTs) is challenging. There has been no consensus for critical antibody titers in the transfusion community. This study was conducted to understand the trends of anti-A and anti-B antibody titer levels in O group donors and to identify any specific patterns of distribution in relation to age and gender.

MATERIALS AND METHODS

A total of 1635 Group O PLT donors were randomly selected for this prospective study. Serial 2-fold doubling dilutions were prepared for each sample to calculate the titer of anti-A and anti-B in a standard 96 well micro-plate. Tube technique was used for comparison with the microplate method for 100 samples.

RESULTS

Out of 1635 donors, 1430 (87.46%) were males and 205 (12.54%) were females. The median titer for anti-A and anti-B was 128 with range from 4 to 2048. Spearman's correlation coefficient for microplate versus tube technique was estimated to be 0.803 (P < 0.01, two-tailed). 57.12% and 51.19% of all donors had titers ≥128 for anti-A and anti-B, respectively. The geometric mean of anti-A and anti-B was 155.7 and 137.28, respectively. The titers were significantly higher (P < 0.001) in female donors. An inverse relation between titer levels and age was seen.

CONCLUSION

Microplate can be used to perform titers in resource-constrained settings. Screening for critical titers in O group donors is essential as they are more implicated in hemolytic transfusion reactions. In the absence of a global consensus on this topic, institutes may need to formulate their own guidelines on handling ABO plasma-incompatible PLT transfusions.

How do I implement an automated screen for high-titer ABO antibody as an inventory management tool for ABO plasma-incompatible platelets?

BACKGROUND

Plasma volume reduction (PVR) may reduce the risk of hemolysis associated with transfusion of plateletpheresis blood products (PLTs) containing ABO-incompatible plasma. But PVR may delay PLT issue. In collaboration with our blood donor center we evaluated an automated screen of PLT for high-titer ABO antibody and to apply PVR to high-titer PLTs.

STUDY DESIGN AND METHODS

At the donor center, plasma from PLT donors was tested using an automated microplate system (PK7300, Beckman). PK settings were set for a detection cutoff equivalent to 1 in 256 using a manual tube method. The donors associated with high-titer PLTs were characterized by sex and age. In the transfusion service, the number of PVR procedures was evaluated before and after implementation of the high-titer screen.

RESULTS

During validation, 157 of 1008 PLT units (15%) were positive by the automated method versus 121 (12%) by manual method. After implementation, 2112 of 15,240 PLT units were high-titer, with higher frequency in donations from females versus males (18% vs. 12%, p < 0.0001). The PLT PVR rate was reduced by 50%.

CONCLUSION

Implementation of an automated method to screen PLTs for high-titer ABO antibody at the donor center improves the inventory management of PLTs containing ABO-incompatible plasma at the hospital transfusion service.

The Blood Group A Genotype Determines the Level of Expression of the Blood Group A on Platelets But Not the Anti-B Isotiter

BACKGROUND

The extent of expression of the blood group A on platelets is controversial. Further, the relation between platelets' blood group A expression and the titers of isoagglutinins has not been thoroughly investigated, so far.

METHODS

We evaluated the relation between the genotype with platelets' blood group A and H expression estimated by flow cytometry and the titers of isoagglutinins.

RESULTS

The A expression varied between genotypes and within genotypes. However, the expression in A1 was stronger than in all other genotypes (p < 0.0001). An overlap of expression levels was apparent between homozygous A1A1 and heterozygous A1 individuals. Still, The A1A1 genotype is associated with a particularly high antigen expression (p = 0.009). Platelets' A expression in A2 versus blood group O donors was also significant (p = 0.007), but there was again an overlap of expression. The secretor status had only little influence on the expression (p = 0.18). Also, isoagglutinin titers were not associated with genotypes.

CONCLUSION

To distinguish between A1 and A2 donors may reduce incompatible platelet transfusions and therefore be favorable on platelet transfusion increment. Clinical data are needed to support this notion.

Comparison of two platelet transfusion strategies to minimize ABO-nonidentical transfusion, outdating, and shortages using a computer-simulated "virtual blood bank"

BACKGROUND

Transfusion of ABO-incompatible platelets (PLTs) is associated with reduced PLT recovery and a risk of transfusion reactions. However, a policy of transfusing only ABO-identical PLTs may increase wastage due to product outdating. A prospective study attempting to compare the effects of different ABO compatibility strategies could be costly and disruptive to a blood bank's operations.

STUDY DESIGN AND METHODS

We designed a "virtual blood bank," a stochastic computer program that models the stocking and release of products to meet demand for PLT transfusion in a simulated hospital population. ABO-nonidentical transfusions (ABOni), outdates, and inventory shortages were recorded and compared under two different transfusion strategies: ABO-First, a strategy that prioritizes transfusion of ABO-identical PLTs, and Age-First, a strategy that minimizes outdating by transfusing products closest to expiration.

RESULTS

The ABO-First strategy resulted in fewer ABOni but more outdates than the Age-First strategy. Under conditions that mimic a large hospital blood bank, the ABO-First strategy was more cost-effective overall than the Age-First strategy if avoiding an ABOni is valued at more than $19 to $26. For a small blood bank, the ABO-First strategy was more cost-effective if avoiding an ABOni is valued at more than $104 to $123.

CONCLUSION

Based on a virtual blood bank computer simulation, the cost of avoiding an ABOni using the ABO-First strategy varies greatly by size of institution. Individual blood banks must carefully consider these management strategies to determine the most cost-effective solution.

Split Blood Products

The last 20 years have seen many advances in transfusion therapy and safety. Blood products are biological products engendering complex interactions with the immune system. Prestorage leukoreduction results in a reduced risk of febrile reactions, CMV transmission, and immune modulation, proving to be safer for patients than non-leuko reduced products.

Simple patient identification issues and clerical error continue to be the primary causes of ABO-incompatible transfusions. Rigorous donor screening as well as serologic and nucleic acid testing for transfusion transmitted infection have brought the blood supply to a very safe level, although transmission of these agents continues to be a problem in underdeveloped countries. Emerging infectious diseases, beyond current laboratory detection capabilities, combined with global travel, pose unknown imminent risks everywhere. We also briefly discuss the current risks of transfusion-transmitted infections.

We review currently available hemostatic blood products, their compositions, and their clinical indications; we mention product modifications currently in development; and we touch upon the hemostatic properties and drawbacks of whole blood, which is currently gaining popularity as an alternative to split blood products. We conclude with an in-depth overview of the risks associated with transfusion, including incompatibility, hemolytic transfusion reactions, transfusion-associated circulatory overload (TACO), and transfusion-related acute lung injury (TRALI).

Safety of platelet transfusion: past, present and future

Platelet components became routinely available to many institutions in the late 1960s and since then utilization has steadily increased. Platelets are produced by three principal methods and their manufacturing process is regulated by multiple agencies. As the field of platelet transfusion has evolved, a broad array of strategies to improve platelet safety has developed. This review will explore the evolution of modern platelet component therapy, highlight the various risks associated with platelet transfusion and describe risk reduction strategies that have been implemented to improve platelet transfusion safety. In closing, the reader will be briefly introduced to select investigational platelet and platelet-mimetic products that have the potential to enhance platelet transfusion safety in the near future.

The association between red blood cell and platelet transfusion and subsequently developing idiopathic pneumonia syndrome after hematopoietic stem cell transplantation

BACKGROUND

Blood transfusions are common during hematopoietic stem cell transplantation (HSCT) and may contribute to lung injury.

STUDY DESIGN AND METHODS

This study examined the associations between red blood cell (RBC) and platelet (PLT) transfusions and idiopathic pneumonia syndrome (IPS) among 914 individuals who underwent myeloablative allogeneic HSCT between 1997 and 2001. Patients received allogeneic blood transfusions at their physicians' discretion. RBCs, PLTs, and a composite of "other" transfusions were quantified as the sum of units received each 7-day period from 6 days before transplant until IPS onset, death, or Posttransplant Day 120. RBC and PLT transfusions were modeled as separate time-varying exposures in proportional hazards models adjusted for IPS risk factors (age, baseline disease, irradiation dose) and other transfusions. Timing of PLT transfusion relative to myeloid engraftment and PLT ABO blood group (match vs. mismatch) were included as potential interaction terms.

RESULTS

Patients received a median of 9 PLT and 10 RBC units. There were 77 IPS cases (8.4%). Each additional PLT unit transfused in the prior week was associated with 16% higher IPS risk (hazard ratio, 1.16; 95% confidence interval, 1.09-1.23; p < 0.001). Recent RBC and PLT transfusions were each significantly associated with greater risk of IPS when examined without the other; only PLT transfusions retained significance when both exposures were included in the model. The PLT association was not modified by engraftment or ABO mismatch.

CONCLUSION

PLT transfusions are associated with greater risk of IPS after myeloablative HSCT. RBCs may also contribute; however, these findings need confirmation.

Platelet transfusion - the art and science of compromise

SUMMARY

Many modern therapies depend on platelet (PLT) transfusion support. PLTs have a 4- to 7-day shelf life and are frequently in short supply. In order to optimize the inventory PLTs are often transfused to adults without regard for ABO compatibility. Hemolytic reactions are infrequent despite the presence of 'high titer' anti-A and anti-B antibodies in some of the units. Despite the low risk for hemolysis, some centers provide only ABO identical PLTs to their recipients; this practice might have other beneficial outcomes that remain to be proven. Strategies to mitigate the risk of hemolysis and the clinical and laboratory outcomes following ABO-matched and mismatched transfusions will be discussed. Although the PLTs themselves do not carry the D antigen, a small number of RBCs are also transfused with every PLT dose. The quantity of RBCs varies by the type of PLT preparation, and even a small quantity of D+ RBCs can alloimmunize a susceptible D- host. Thus PLT units are labeled as D+/-, and most transfusion services try to prevent the transfusion of D+ PLTs to D- females of childbearing age. A similar policy for patients with hematological diseases is controversial, and the elements and mechanisms of anti-D alloimmunization will be discussed.

ABO incompatible platelets: risks versus benefit

PURPOSE OF REVIEW

The importance of ABO blood group system compatibility in platelet transfusion is a subject of ongoing debate. Although there are theoretical advantages to pursuing a strict policy of providing exclusively ABO-compatible products, resource challenges may make this untenable for many transfusion services. Moreover, data supporting a net clinical benefit for this practice have been lacking. This review summarizes recent developments in the area of ABO compatibility and platelet transfusion and examines the risks and benefits associated with transfusion practices allowing for platelet ABO incompatibility.

RECENT FINDINGS

ABO-major incompatible transfusions are associated with lower platelet count increments than either ABO identical or minor incompatible transfusions and may lead to decreased intervals between platelet transfusions in thrombocytopenic patients. ABO-minor incompatible transfusions may rarely result in acute hemolytic reactions that are not predicted by isohemagglutinin titers. Yet published evidence to date does not clearly demonstrate improvements in clinical outcomes for patients receiving ABO-identical or ABO-compatible platelets. Adherence to a strict policy of transfusing exclusively ABO-identical platelets may lead to an increase in product wastage and challenges in maintaining adequate platelet availability.

SUMMARY

There is presently limited data and no consensus on the best approach for managing ABO compatibility in platelet transfusions. Well designed, sufficiently powered randomized clinical trials are urgently needed. These studies must examine not only safety and efficacy of various ABO matching strategies but also clinical benefit and resource utilization in order to identify optimal platelet transfusion strategies.

Risks of hemolysis due to anti-A and anti-B caused by the transfusion of blood or blood components containing ABO-incompatible plasma

BACKGROUND

The increasing use of fresh blood group O whole blood in acute trauma medicine makes it important to reevaluate the issue of hemolytic reactions related to the transfusion of ABO-incompatible plasma.

STUDY DESIGN AND METHODS

This review summarizes and evaluates published articles and case reports concerning hemolytic reactions in connection with the transfusion of group O whole blood or blood products to nongroup O recipients.

RESULTS

In 1945-1986, 15 nonmilitary publications reported hemolytic transfusion reactions with group O blood/blood products. All patients recovered except for two fatalities. Late in World War II and during the Korean and Vietnam wars and onward in Iraq and Afghanistan only "low anti-A, anti-B titer" group O whole blood has been used as universal blood. In spite of a large number of units transfused, there are no reports of hemolytic reactions. Twenty-five publications report hemolytic reactions after transfusion of group O platelets to nongroup O recipients. In all patients but one, the titer of the implicated A- or B-antibody was >100 (saline) or >400 (antiglobulin) and all cases with an infused volume of incompatible plasma <200 mL were related to anti-A or anti-B antiglobulin titers >1000.

CONCLUSION

In emergency lifesaving resuscitation, the risk of hemolytic transfusion reactions from transfusion of group O blood to nongroup O recipients constitutes risk that is outweighed by the benefits. A low titer of anti-A/B will minimize the risk for a hemolytic reaction, particularly if the screening is repeated after an immunization episode, e.g., blood transfusion, vaccination, or pregnancy.

The characteristics of ABO antibodies in group O Thai blood donors

This study aimed to characterize anti-A and anti-B hemolysins, IgM, and IgG titers in Thai blood donors. Altogether, 300 serum samples from group O donors at the National Blood Centre, Thai Red Cross Society, were screened for anti-A and anti-B hemolysins and treated with 0.01 M dithiothreitol to characterize IgM and IgG titers by standard tube technique. Antibody titers were compared with hemolysis grade. Male and female ratio = 1:1.3 and ages ranged from 17 to 60 years. The overall prevalence of anti-A and anti-B hemolysins was 69%. Anti-A and anti-B hemolysins comprised 18.3% and 16.7%, respectively and 34% had both antibodies. High titers of anti-A hemolysins were associated with females (P< 0.05), and only anti-B IgM titers were associated with age (P< 0.05). Interestingly, the association of anti-A IgM titers, anti-A IgG titers, and hemolysin grade was demonstrated (P< 0.05). A significant association between hemolysin grade and anti-B IgM titers was found (P< 0.05). The prevalence of anti-A and anti-B hemolysins and high titers of IgM and IgG in Thais are high. Hemolysin grade showed significant associations with IgM titers; therefore, when providing ABO-incompatible platelet transfusion, especially for female plateletpheresis donors, IgM high titers of anti-A and anti-B screening is suggested.

ABO antibody titers are not predictive of hemolytic reactions due to plasma-incompatible platelet transfusions

BACKGROUND

The overall risk of hemolytic transfusion reactions (HTRs) from plasma (minor)-incompatible platelet (PLT) transfusions and the role of a critical anti-A or anti-B titer in predicting and preventing these reactions has not been clearly established.

STUDY DESIGN AND METHODS

We evaluated all apheresis PLT (AP) transfusions for 3 months. Using the gel titer method, we determined the anti-A and/or the anti-B immunoglobulin (Ig)G titer for all incompatible APs. Reported febrile transfusion reactions and HTRs were recorded; transfusions were not prospectively evaluated by the study team. A posttransfusion direct antiglobulin test (DAT) and eluate were performed after a reported febrile or hemolytic reaction for patients who received plasma-incompatible APs.

RESULTS

A total of 647 of 4288 AP transfusions (15.1%) were plasma incompatible. Group O APs (n = 278) had significantly higher anti-A and anti-B titers than group A or B APs (p < 0.0001). No group A or B APs had a titer of more than 128 (0/342). For group O APs, 73 had titers of 256 or greater (26.3%), and 27 had titers of 512 or greater (9.7%). No HTRs were reported to any plasma-incompatible AP transfusion during the study period. Two plasma-incompatible AP transfusions were associated with fever and chills and positive DATs, of which one had a positive eluate. The incidence of a DAT and eluate-positive febrile transfusion reaction in the plasma-incompatible AP population is 0.15% (95% confidence interval, 0.0%-0.86%).

CONCLUSION

A critical anti-A or -B titer is not sufficient to predict the risk of hemolysis in patients receiving plasma-incompatible APs, although underreporting of reactions to the blood bank may limit the generalizability of this study.

Adverse effects of plasma transfusion

Plasma utilization has increased over the past two decades, and there is a growing concern that many plasma transfusions are inappropriate. Plasma transfusion is not without risk, and certain complications are more likely with plasma than other blood components. Clinical and laboratory investigations of the patients suffering reactions after infusion of fresh-frozen plasma (FFP) define the etiology and pathogenesis of the panoply of adverse effects. We review here the pathogenesis, diagnosis, and management of the risks associated with plasma transfusion. Risks commonly associated with FFP include: 1) transfusion-related acute lung injury, 2) transfusion-associated circulatory overload, and 3) allergic and/or anaphylactic reactions. Other less common risks include 1) transmission of infections, 2) febrile nonhemolytic transfusion reactions, 3) red blood cell alloimmunization, and 4) hemolytic transfusion reactions. The effects of pathogen inactivation or reduction methods on these risks are also discussed. Fortunately, a majority of the adverse effects are not lethal and are adequately treated in clinical practice.