Treatment and prevention of DIC during haemolytic transfusion reaction is controversial. @~ (* {d+}G}WL$cGD2QZ4 E@@ A(q`1D `'u46ptc48.`R0) However, there is no accepted and clear definition for high-titer antibodies. It had vasoconstrictive and, as a result, hypertensive effect. Since most patients receive more than one unit of red blood cell concentrate, the estimated incidence of delayed haemolytic transfusion reactions is from 1:854 to 1:524 per patient who has been transfused and is higher than per transfused unit [7]. It can occur during transfusion or up to 24h after transfusion of red blood cells. Low concentration cytokines include IL-1, IL-6 and TNF-. This effect is largely attributed to the binding nitric oxide by free haemoglobin (NO) [36]. Bilirubin concentration depends on the severity of haemolysis and liver function. Nevertheless, major ABO-incompatibility needs to be considered and appropriately ruled out in case of acute reactions after transplantation. As long as PRCA persists (usually weeks to months until the isohemagglutinins have been adsorbed), transfusion requirements are high with consequent iron overload and potentially negative impact on overall survival.16 Management of post-transplant PRCA may include (besides transfusions) rituximab, anti-thymocyte globulin, TPE or immunoadsorption, decrease/discontinuation of immunosuppression, and donor lymphocyte infusions.8 Although plausible from a pathophysiologic point of view, none of these practices have been proven to be effective. Investigation may be difficult because the differential diagnosis is often broad. It is probably the result of direct stimulation of nociceptive nerves in perivascular tissue by bradykinin, which, in turn, is released during sudden activation of complement [37]. In contrast, anti-K, anti-Fya antibodies react in an anti-globulin test. Post-transplant AIHA is often therapy resistant and associated with decreased survival. Minor ABO-incompatible HSCT is characterized by the transfer of donor isohemagglutinins directed against the recipient's RBC antigens. Its based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. On blood cells with the Cromer mull phenotype, known as Inab, DAF inhibitor expression is absent [17, 18]. *All RBC concentrates should be -irradiated (25-30 Gy) and leukocyte reduced. WebNon-immune hemolytic anemia (NIHA) is characterized by positive routine hemolytic tests but negative anti-human immunoglobulin (Coombs) test. Blood clots that form in the renal arterioles cause cortical kidney attacks. 0000000845 00000 n Anemia of chronic By making research easy to access, and puts the academic needs of the researchers before the business interests of publishers. Changes in laboratory indicators in haemolytic transfusion reactions [56]. Impaired renal function is observed in both intravascular and extravascular haemolytic transfusion reactions, although definitely more frequently in the case of intravascular. In the pathogenesis of DIC, interactions between the blood coagulation system and mediators of the inflammatory response are also of great importance [27]. In addition, every HSCT candidate, as well as the corresponding donor, can have additional conditions leading to HA (eg, glucose-6-phosphate dehydrogenase deficiency). How long does it take for a hemolytic transfusion to occur? Andreas Holbro, Division of Hematology, Department of Internal Medicine, University Hospital, Petersgraben 4, 4031 Basel, Switzerland; Phone: 0041-61-265-25-25; Fax: 0041-61-265-44-50; e-mail: andreas.holbro@usb.ch. Human Blood Group Systems and Haemoglobinopathies, Submitted: June 11th, 2019 Reviewed: January 6th, 2020 Published: March 3rd, 2020, Edited by Osaro Erhabor and Anjana Munshi, Total Chapter Downloads on intechopen.com. The cause of an early haemolytic reaction may also be congenital haemolytic anaemia, for example, glucose-6-phosphate dehydrogenase deficiency or microangiopathic haemolytic anaemia (TTP, HUS and HELLP). The test should be performed on serum/plasma samples taken before and after transfusion. A negative DAT result does not exclude haemolysis, it may mean that the transfused blood cells have been destroyed by alloantibodies or the method used is not very sensitive. However, the symptoms in some recipients, or the occurrence of a reaction already during a blood transfusion and haemoglobinuria, indicate that the destruction of blood cells also takes place inside the vessel. However, in those with non-hemolytic delayed serologic transfusion reactions (NH-DSTRs), the threat applies more towards the future rather than the present time. Risk factors, including endothelial damage by conditioning agents (including irradiation), medications (immunosuppressants like calcineurin inhibitors and sirolimus), and viral infections have been identified. Antibodies capable of destroying transfused blood cells are called clinically relevant antibodies, and the transfusion reaction in the event of immunological incompatibility depends on: (1) specificity of antibodies; (2) thermal amplitude of the antibodies; (3) IgG classes and IgG subclasses; (4) number, density and spatial configuration of antigenic sites on red blood cells; (5) the ability of antibodies to activate the complement system; (6) plasma concentrations of antibodies and (7) volumes of transfused red blood cells. Pyruvate kinase deficiency. Features of antibodies (specificity, class and heat amplitude) and antigens (density of antigenic sites and their distribution) against which the antibodies directed are interconnected. Spath etal. Diagnosis and treatment of transplantation-associated thrombotic microangiopathy: real progress or are we still waiting? Therefore, if possible, blood without this antigen should be selected [41]. Positive DAT with anti-IgG reagents or with anti-IgG and anti-C3 reagents is generally seen as two red blood cell populations. 0000002243 00000 n Search for other works by this author on: 2016 by The American Society of Hematology. In oxyHb, cysteine is exposed at position 93 of the haemoglobin amino acid chain (Cys 93). Haemolysis may also occur due to non-immunological reasons, such as thermal, osmotic or mechanical damage to the transfused blood; bacterial infection or extremely rare and blood transfusion from a donor with congenital haemolytic anaemia due to deficiency of glucose-6-phosphate dehydrogenase [2]. After 24 incubations with incompatible red blood cells, monocytes show a significant increase in CD44 levels. Additionally, each center should define policies and standard operating procedures for the prevention and management of complications after ABO-incompatible HSCT (Table 3).19 Definite ABO blood group assignment should be done after a transfusion-independent interval, full engraftment, remission of the underlying disease, and in close collaboration with the treating physicians. The number of reported cases of delayed haemolytic transfusion reaction was higher than in 2016, but comparable with previous years [6]. We follow the timeline of the transplantation process and discuss investigations, differential diagnosis, and prophylactic measures including graft processing to avoid hemolysis in case of ABO incompatibility. The frequency of reporting haemolytic transfusion reactions may also depend on other factors, such as patient population, transfusion response reporting system and medical staff education. Additionally, differential diagnosis is not always obvious and patients can present with several potential risk factors for TMA (Table 4). Positive reactions with allogeneic blood cells are accompanied by positive auto control of the patients red blood cells. Monitoring for clinical and laboratory signs of hemolysis is mandatory and in case of massive hemolysis frequent hemoglobin measurements should be performed. WebFebrile Non-Hemolytic Transfusion Reaction (FNHTR): FeverOR chills and rigors occurring within 4 hours of transfusion.Signs and symptoms include fever (greater than or equal to38C/100.4F oral and a change of at least 1C/1.8F) frompre-transfusion value) or chills/rigors.Acute Hemolytic Transfusion Reaction (AHTR): Hemolysisoccurring within D indicates donor ABO blood group; PLT, platelet; R, recipient ABO blood group; and RBC, red blood cell. The nature of the reaction may not be immediately apparent, Usually, plasma alloantibodies are detectable at 47days after the transfusion and reach maximum activity between 10 and 15days after the transfusion. Table 5 presents features of delayed haemolytic transfusion reaction and the time of their occurrence. Another method of treating early haemolytic transfusion reaction is to use a high dose of 0.4/kg intravenous immunoglobulin per 24h after blood transfusion. The mean age of all patients was 57 ( 17) with 49.4% of reactions occurring in females. However, it should be remembered that these difficulties must not cause risk of haemorrhage. On the one hand, these processes lead to the production of a large amount of thrombin that converts fibrinogen to fibrin. University of Alabama at Birmingham Hospital. 4 0 obj The distribution of TRs (Figure 1) included 562 (71.8%) non-anti-RBC TRs and 221 (28.2%) anti-RBC TRs. Another cause for haemolytic transfusion reaction may be a secondary immune response in patients who have developed alloantibodies during previous transfusions of blood components or pregnancy. Alloantibodies responsible for haemolysis, needle diameter too small, haematocrit of transfused red blood cells too high, an inappropriate method of freezing/thawing red blood cells, mechanical damage to blood cells, artificial valves, Drug-induced haemolysis of red blood cells. They then become clinically significant. /Filter /FlateDecode Table 8 presents changes in laboratory indicators in transfusion haemolytic reactions [56]. London, SW7 2QJ, In the case of minor incompatibility both immediate and delayed hemolysis can occur.21 In this case, management is similar to ABO-incompatibility. But until then, HTRs will remain the most important adverse post-transfusion reaction. This means that after transfusion of red blood cells, the production of alloantibodies directed to the antigen found on the transfused blood cells occurs. Blood cells are destroyed as a result of the activation of the binding of the remaining components of C8 and C9 complement and the formation of the MAC complex on the blood cells [56]. Consider HLA-alloimmunization. C5b binds to C6, then to C7. trailer The results of these studies indicate a critical role of monocyte activation in the development of intravascular haemolytic transfusion reaction [15]. 0000007661 00000 n 2020 The Author(s). Acute transfusion reactions range from bothersome yet clinically benign to life-threatening reactions. WebHemolytic transfusion reactions are recognized as an important cause of transfusion-associated reactions and may be subclinical, mild, or lethal. In this condition, your immune system makes antibodies (proteins) that attack your red blood cells. For example, for 70kg recipient, about 18ml of transfused red blood cells are destroyed per hour. Similar reactions to anti-A and anti-B come from anti-PP1Pk, anti-P1 and anti-Vel. The quoted breakdown of reactions is somewhat artificial, because the symptoms associated with haemolytic reactions sometimes overlap [1]. Identification is critical because of the high probability of a second patient receiving the wrong blood product at the same time. Data Collection The mechanism of appearance of intravascular symptoms has not been fully explained, because although some of the antibodies bind complement components, their reactions end with C3 components. The severity of this abnormality varies greatlyfrom asymptomatic increase in urea (BUN) and serum creatinine up to complete anuria. In summary, awareness of possible complications after ABO-incompatible HSCT and early recognition and institution of appropriate measures are essential. They may interact with CR1 and CR3 receptors on macrophages and consequently undergo phagocytosis. Among alloantibodies, such haemolysis is induced by anti-A and anti-B, rarely anti-Jka, anti-Jkb, anti-Vel, anti-P, anti-Lea and very unique antibodies with other specificities [10, 11]. Steroids should be administered at a dosage of 1-2 mg/kg. TNF- is released first, its elevated concentration is already detected within first 2h. It carries a pro-inflammatory potential that is responsible for fever, leukocyte activation, stimulation of procoagulant activity, increased antibody production and vascular wall permeability [22]. Lua antigens have uneven distribution on red blood cells and are weakly immunogenic. Search for other works by this author on: An Updated Report by the American Society of Anesthesiologists Task Force on Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration, A Tool to Screen Patients for Obstructive Sleep Apnea, ACE (Anesthesiology Continuing Education), https://doi.org/10.1097/00000542-194601000-00029, 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway, 2023 American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting: Carbohydrate-containing Clear Liquids with or without Protein, Chewing Gum, and Pediatric Fasting DurationA Modular Update of the 2017 American Society of Anesthesiologists Practice Guidelines for Preoperative Fasting, Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures, Reducing Noninfectious Risks of Blood Transfusion, Use of Uncrossmatched Erythrocytes in Emergency Bleeding Situations. One of the reasons for this haemolytic reaction is the binding of the C567 complement complex, activated in an immune reaction, to the membrane of red blood cells not participating in the reaction but located in the vicinity [56]. The introduction of haemovigilance transfusiological surveillance systems has enabled the analysis of all fatal and severe transfusion reactions. pain and nausea). However, it is worth noting that despite the low intensity of haemolysis, the survival time of red blood cells after transfusion is significantly reduced [2]. This topic will mainly address immune-mediated transfusion reactions, which comprise an array of distinct adverse clinical responses to transfusion. No cases of acute haemolytic reaction caused by anti-Lua antibodies have been reported, delayed transfusion haemolytic reaction is rare and occurs only in mild form. The specificity of the antibodies potentially responsible for intravascular and extravascular haemolysis is shown in Table 4. The presence of these isohemagglutinins and the involvement of the donor's and recipient's immune system are responsible for hemolytic complications (Table 2). The incidence of haemolytic transfusion reactions, Mechanisms of haemolytic transfusion reactions, Mediators of inflammatory reactions in haemolytic transfusion reactions, Complications of haemolytic transfusion reactions, Clinical symptoms of transfusion haemolytic reactions, Causes of haemolytic transfusion reactions, Diagnosis of transfusion haemolytic reactions, Treatment of transfusion haemolytic reactions, Prevention of haemolytic transfusion reactions. A panel of standard cells should contain clinically important antigens in a homozygous form to detect the presence of weak antibodies. These include, among others, errors in collecting blood samples from patients and blood transfusions to a wrong patient. In addition, acute and delayed transfusion reactions because of a transfusion error should always be excluded, according to the local policies. In different people, antibodies with a particular specificity most often occur in the same class of immunoglobulins and have a similar heat amplitude, for example, anti-A, anti-B and anti-AB from the ABO system often belong to both IgM and IgG classes, they bind complement and have an extended thermal amplitude of up to 37C. A characteristic feature of the cell membrane of these blood cells is the lack or weak expression of the CD55 (DAF) and CD 59 (MIRL) proteins, which are complement inhibitors. Autoimmune hemolytic anemia. Most of the cells coated by the complement C3b component are destroyed by liver macrophages, that is, by Kupffer cells, while the cells coated with antibody molecules are mainly destroyed by spleen macrophages. /Length 11 0 R It is noteworthy that in patients with a haemolytic reaction associated with the immune cytolysis of the bystander not only transfused red blood cells but also autologous blood cells of the patient were destroyed. Renal failure and DIC are also more commonly associated with intravascular haemolysis. CP declares that he has no competing interests. These reactions can occur acutely or in a delayed timeframe, while the sensitizing antibody may derive from the host or be passively acquired. In differential diagnosis, attention should also be paid to non-immune reasons related to improper blood storage, transfusion of red blood cells through a small needle diameter, etc. Convertase breaks down molecules of C3 into C3a, C3b, C3c and C3d. The occurrence of pain in the haemolytic transfusion reaction is not clear. Again, evidence is too weak to support treatment with TPE.14,41, Autoimmune diseases (ADs) after both autologous and allogeneic (including cord blood) HSCT may occur regardless of the underlying disease.42-44 The exact mechanisms and the pathophysiology of post-transplant ADs are not yet fully understood. The decision to carry it out must be balanced and the course carefully monitored. Andreas Holbro, Jakob R. Passweg; Management of hemolytic anemia following allogeneic stem cell transplantation. Acute hemolytic transfusion reactions tend to present immediately or within several hours after transfusion as fever, chills, chest pain, or hypotension. MIRL inhibits membrane attack complex [15, 17]. Pure red cell aplasia (PRCA) may develop in up to 30% of patients after major ABO-incompatible HSCT, because of persistence of recipient plasma cells producing anti-donor isohemagglutinins, thus blocking normal erythroid maturation.8,15 Delayed red cell engraftment and PRCA are more common in reduced intensity transplantation (RIC) where donor and recipient hematopoiesis coexist and in cord blood transplantation. Parvovirus B19 infection has to be excluded. Number of antigenic determinants on the cell surface of the red blood cell (according to [12, 13]). 0000000016 00000 n This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. It is most important to observe the clinical symptoms of the recipient and stop the blood transfusion at the right moment. Low doses of dopamine (15g/kg/min) may be used to maintain renal circulation, but this may not be effective. Therefore, prior to conducting laboratory tests of donor blood, bacteriological examination of the component remaining after the transfusion cessation should be conducted. In addition, hypertension and proteinuria can be the early signs of TA-TMA, although these manifestations are encountered frequently in patients after HSCT.26,27,34,35 Soluble membrane attack complex (sC5b-9) may be elevated and is associated with a poor prognosis.30 Diagnosis can be confirmed by renal biopsy, which shows typical histologic findings, although there is little correlation between clinical and pathologic diagnosis. Copyright 2023 by American Society of Hematology, 401. Hemolytic transfusion reaction. A hemolytic transfusion reaction is a serious complication that can occur after a blood transfusion. The reaction occurs when the red blood cells that were given during the transfusion are destroyed by the person's immune system. When red blood cells are destroyed, the process is called hemolysis. There are other ), and blood chemistry [bilirubin, lactate dehydrogenase (LDH), and creatinine] are mandatory. HA in general is either inherited or acquired, intravascular or extravascular, and immune or nonimmune mediated. Do you want to go to BMJ Best Practice for United Statesinstead? Books > In the case of haemolysis of red blood cells, the free haemoglobin released from them reacts with NO much faster and more strongly than Hb inside cells [35]. Repeated transfusions of ABO incompatible platelet concentrate may lead to accumulation of anti-A antibodies in the recipients plasma, which may result in severe haemolytic reactions [52]. A comparison was also made against all inpatient TRs not due to RBC antibodies (non-anti-RBC TRs). They activate the complement system to the stage of binding of the C3b component, causing extravascular haemolysis. For this purpose, specific polymerase chain reaction from bone marrow specimens is considered to be a standard. WebTransfusion Reactions Allergic Hemolytic (Acute; Delayed) Bacterial Febrile non-hemolytic TRALI Volume Overload Transfusion Reactions: Signs & Symptoms Fever Hypotension Chest Tightness/Dyspnea Nausea/Vomiting etc Immuno-Hemolytic Transfusion Reactions Intravascular vs Extravascular Immediate vs Delayed RE: It is manifested by a rapid decrease in haemoglobin, haemoglobinemia and haemoglobinuria and can potentially be life threatening [2]. However, this is rarely done and potential bleeding risks have to be balanced against the diagnostic benefits of this procedure.28 Unfortunately, there are no controlled trials and thus there is no consensus on the management of TA-TMA. Hematology Am Soc Hematol Educ Program 2015; 2015 (1): 378384. It is possible that technological progress enabling modification of red blood cells and the use of red blood cell substitutes will significantly change transfusion practice in the future and eliminate the occurrence of haemolytic transfusion reactions. DAT should be performed, although it can be negative in case of rapid clearance of isohemagglutinin-loaded recipient RBCs. In contrast, prospective studies also contain errors due to reaction symptoms often remaining unrecognised or masked by associated diseases, for example, bleeding or liver disease [1]. Red blood cells can be absorbed and completely digested inside the macrophage. Laboratory testsmainly serologicalare crucial for the diagnosis of an early haemolytic reaction. Therefore, HA can also occur as a consequence of alloantibodies against non-ABO RBC antigens and has the same pathophysiology as PLS.8,20,21 The Rhesus (Rh) system is the one most frequently described. In unconscious patients and patients under general anaesthesia, it may be difficult to recognise a haemolytic transfusion reaction, as some symptoms may go unnoticed (e.g. PLS is more common in patients with blood group A, with a donor of group O, and cyclosporine A (CYA) alone as GVHD prophylaxis. In clinical practice, however, such antibodies can sometimes destroy donor blood cells. TNF- also stimulates endothelial cells to synthesise adhesion molecules and chemotactic cytokines [22]. <<488cdda8e0677b47a7accfabb5999f1d>]>> For exchange transfusion, red blood cells without an antigen should be used against which the patient has developed alloantibodies. Licensee IntechOpen. Initial symptoms of haemolytic transfusion reactions. Receptors for complement activation products C3a and C5a are found on many cells: monocytes, macrophages, neutrophils, platelets, endothelium and smooth muscle. Causality is not established by this analysis, nor is there a biologic rationale for a NH-DSTR to directly impact LOS. {{{;}#tp8_\. Preventing haemolytic transfusion reactions by focusing on advances in serology and transfusion medicine has significantly reduced their incidence. In the presence of schistocytes and thus the suspicion of microangiopathy, measurement of ADAMTS13 should be considered. WebFebrile nonhemolytic reaction: Headache, fever of38C/100.4F (or an increase of 1C/1.8F from baseline),chills, rigors, and generalized discomfort Allergic reaction: Generalized flushing, rash, hives, itching,angioedema, conjunctival edema, facial edema, hypotension,and/or asthmatic wheezing, and can progress to laryngealedema and The expression of these membrane inhibitors is associated with Cromer group system and CD59. In case of immune-mediated hemolysis, a direct antiglobulin test (DAT), elution (also against a non-O RBC panel in case of ABO incompatibility), isohemagglutinin titration, and absorption techniques are required. Such reactions were observed in the following blood group systems: Rh, MNSs, Lutheran, Kell, Duffy, Diego and Lewis. This varies depending on the graft source, as bone marrow contains more RBCs compared with peripheral blood progenitor cells (PBSCs) collected by apheresis and cord blood (CB). Often the way out of this situation is transfusion of O RhD negative red blood cells. A bidirectional blood-group barrier is a combination of major and minor ABO incompatibilities. 0000002721 00000 n In general, AD can affect every organ and occur alone or in combination.42 Autoimmune cytopenias after HSCT (including AIHA, immune thrombocytopenia, and immune neutropenia, or a combination of them) occur frequently.45-47 Incidence ranges from 1.3% to 4.4% and the risk factors for the development of AIHA are transplantation from an unrelated donor, development of chronic GVHD and a nonmalignant primary disease.45 Disease course is variable, ranging from spontaneous remissions to life-threatening and even fatal hemolysis. Lack of these particles may increase the susceptibility of red blood cells to intravascular haemolysis due to complement activation [19]. Copyright 2023 American Society of Anesthesiologists. IVIG formulations with low isohemagglutinin titers and/or adjustment of dosage can prevent IVIG-induced HA, especially for patients with blood group A. TMA describes a syndrome characterized by microangiopathic HA, thrombocytopenia due to platelet consumption, and microvascular thrombosis (Table 4).25 The formation of platelet-rich thrombi induces mechanical RBC damage and thus intravascular hemolysis. The incidence of autoantibodies after DHTR may be even higher because autoantibodies may mimic the specificity of alloantibodies. CXCL8 primarily activates neutrophils, which leads to the accumulation of leukocytes in the lung vessels of small diameter and damage to the endothelium of blood vessels and their higher permeability [1, 12]. Not all detectable alloantibodies that react with red blood cells can cause a haemolytic reaction. >> UR\#? Latter is also supported by growing data on the use of eculizumab in TA-TMA.28-33, A high index of suspicion is required for the diagnosis of TA-TMA. In contrast, extravascular haemolysis is less dramatic, with a rate of destruction of red blood cells of approximately 0.25ml/h/1kg of recipients body weight. However, there is a danger of bleeding. Why this happens isn't known. Transfusion of plasma, platelet or granulocyte concentrate from donors incompatible in the ABO system with the recipient may lead to acute haemolytic transfusion reaction and even death. *1 J "6DTpDQ2(C"QDqpIdy~kg} LX Xg` l pBF|l *? Y"1 P\8=W%O4M0J"Y2Vs,[|e92se'9`2&ctI@o|N6 (.sSdl-c(2-y H_/XZ.$&\SM07#1Yr fYym";8980m-m(]v^DW~ emi ]P`/ u}q|^R,g+\Kk)/C_|Rax8t1C^7nfzDpu$/EDL L[B@X! Some patients may experience organ failure such as the pancreas, heart and even multiple organ failure that threatens the patients life. However, in those with non-hemolytic Red blood cell transfusion can also stimulate the production of alloantibodies without the occurrence of haemolysis. The prevention of renal failure is aided by an early prevention of hypotension. In some patient groups, it may be difficult to recognise a delayed haemolytic transfusion reaction. Table 2 presents the point algorithm for the diagnosis of acute disseminated intravascular coagulation. Laboratory tests that help to differentiate haemolysis include determination of free haemoglobin in the blood and urine, haptoglobin and lactate dehydrogenase (LDH) and bilirubin. Is Whole Blood Poised for a Return in Civilian Trauma? 0000002797 00000 n Thus, clinical relevant and serious acute hemolytic reactions immediately after graft infusion are rare. [55] analysed reports available in the literature describing cases of haemolysis in patients treated with intravenous immunoglobulins [55]. Your comment will be reviewed and published at the journal's discretion. Special attention should thus be paid to the donor's ABO blood group and the stem cell source, because they differ in terms of the volume of RBC and plasma, and number of lymphocytes.9 RBC antigens are also expressed on other tissues, including endothelial cells (histo-blood groups).