Developing a databank for multiple transfusion patients: Rh antigen and phenotype distribution among 3000 regular blood donors in Iran

BackgroundRhesus (Rh) blood group system is clinically the most significant protein-based grouping system. The Rh system is of vital importance in blood transfusion, and incompatibility between the donor and recipient leads to alloimmunization. Alloimmunization is commonly seen in multiple-transfusion recipients (e.g. thalassemia patients). There are a few studies about the prevalence of Rh antigens, except for D, in Iran; and regarding the high prevalence of thalassemia in the country, in this study we have determined antigens and phenotypes of the Rh among population of regular blood donors with the aim of developing a detailed Rh databank.Materials and methodsThis cross-sectional study randomly enrolled 3000 regular blood donors from three provinces of Sistan-Balouchestan, Khuzestan and Gilan in Iran, from September 2018 to May 2019. A fully automated system, based on hemagglutination, was used to Rh typing of blood samples.ResultsThe prevalence of Rh antigens were as follows: D: 88.9 %; E: 30.9 %; C: 74.1 %; e: 96.2 %; and c: 72.8 %. The most common antigen and phenotype were "e" and R₁r (DCcee), respectively.ConclusionDue to the high rate of alloimmunization incidence against Rh blood group antigens among multiple transfusion recipients, development of regular blood donor's Rh databank can facilitate extensive matching for the Rh antigens and it likely reduces the risk of alloimmunization.     

Transfusion policy in allogeneic hematopoietic stem cell transplantation

The incompatibility of ABO blood group between the recipient and the donor is not a barrier to perform allogeneic hematopoietic stem cell transplantation (Allo-HSCT). However, ABO incompatibility may lead to many complications during and after stem cell transplantation at the early or late period. Therefore, the typing of the blood group of the recipient and the donor should be done prior to the transplantation. In addition, the ABO/Rh group of blood products for transfusion should be determined according to the type of ABO-incompatibility. In this review, the subtypes of ABO blood group-incompatibility and transfusion policies will be discussed in detail.     

Hemotherapy in patients undergoing blood group incompatible bone marrow transplantation

The management of hemotherapy in 31 cases of ABO- or Rh-incompatible bone marrow transplantation is described. Our experience confirms that ABO or Rh incompatibility does not adversely affect engraftment, patient survival, or incidence of graft-versus-host disease. Eighteen recipients with ABO antibodies against the donors' red cells (major incompatibility) were managed by different combinations of plasma exchange, transfusion of incompatible donor type red cells, and removal of donor-type red cells from the bone marrow before transplant. The only serious complication was delayed hemolysis in seven of nine patients who received incompatible red cell transfusions before transplant. Thirteen patients received bone marrow containing ABO antibodies against their red cells (minor incompatibility). Five were managed by centrifuging the bone marrow to remove plasma and reduce the amount of antibody. This did not cause substantial loss of stem cell activity (60-100% of original marrow), and no patients had complications related to the marrow transfusion. In contrast, two of seven patients who received uncentrifuged bone experienced hemolysis. Two of four Rh positive recipients who received marrow from an Rh negative donor developed anti-D, possibly due to Rh positive blood components transfused after transplantation. None of eight Rh negative patients who received an Rh positive transplant has developed anti-D. Blood components should be selected to avoid transfusion of incompatible red cells and to avoid transfusion of a large amount of incompatible plasma. This may necessitate use of plasma components of a different ABO type than the red cell components.     

Evaluation of changes in hemoglobin levels associated with ABO- incompatible plasma in apheresis platelets

BACKGROUND: Hemolytic transfusion reaction is considered a rare complication of platelet transfusion. If minor ABO incompatibility exists (donor antibody directed against recipient's red cells [plasma- incompatible platelets]), however, the antibodies present in the plasma of platelets may cause acute hemolysis. A retrospective study was performed to identify possible hemolysis related to the transfusion of plasma-incompatible apheresis platelets. STUDY DESIGN AND METHODS: Acute hemolysis due to low-titer anti-A present in group O apheresis platelets transfused to a group A patient is reported. Pretransfusion and posttransfusion hemoglobin levels were evaluated in 16 non-group O autologous bone marrow transplant patients receiving apheresis platelets. All patients received, within 24 hours, both ABO-identical and plasma-incompatible platelet transfusions. No red cells were transfused during the time between the collection of the pretransfusion and posttransfusion hemoglobin samples. RESULTS: A total of 24 evaluable paired platelet transfusions in the 16 patients were compared. The mean change in hemoglobin following transfusion of the ABO-identical and plasma-incompatible platelets was -0.50 g per dL and - 0.11 g per dL, respectively (p = 0.193). CONCLUSION: There was no significant change in the hemoglobin concentration associated with the transfusion of plasma-incompatible apheresis platelets (minor ABO incompatibility) in our study group. The case reported here represents the only hemolytic transfusion reaction identified among 46,176 platelet transfusions performed at this hospital, despite approximately 21 percent of all platelet transfusions being plasma incompatible. The risk of such a reaction remains low.     

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.KeyWords: Platelets, ABO, Rh, Mismatch, Hemolysis, Alloimmunization, Antibody     

Intraoperative cell salvage in obstetrics: is it a real therapeutic option?

Obstetric hemorrhage is a leading cause of maternal and perinatal mortality worldwide. Intraoperative blood salvage is common practice in many surgical specialties but its safety in obstetrics is questioned for concerns on the risks of contamination of recovered blood with amniotic fluid (AF) and of maternal-fetal alloimmunization. However, the role of cell salvage as a blood-saving measure in obstetrics is progressively acquiring relevance thanks to the growing body of evidence regarding its quality and safety coming from over 800 documented procedures and more than 400 patients transfused with saved blood. Although the information about the outcomes of the patients treated and the allogeneic blood saving effect are still limited, modern cell savers remove most particulate contaminants and leukoreduction filtering of salvaged blood (SB) before transfusion adds further safety to this technique. Moreover, AF embolism is no longer regarded as an embolic disease and it is suggested that it is a rare anaphylactoid reaction to the fetal antigen. The contamination of the SB by fetal Rh-mismatched red blood cells (RBCs) can be dealt with using RhIG; ABO incompatibility tends to be a minor problem since ABO antigens are not fully developed at birth. Antibodies can be formed against other fetal RBC antigens, but it should also be noted that the risk of alloimmunization of the mother from allogeneic transfusion is probably even greater. Therefore, intraoperative cell salvage in obstetrics should be considered in patients at high risk for hemorrhage or in cases where allogeneic blood transfusion is difficult or impossible.     

Impact of ABO blood group incompatibility on the outcomes of allogeneic hematopoietic stem cell transplantation

Background and aimABO and Rh compatibility are not required between the donor and recipient for allogeneic hematopoietic stem cell transplantation (alloHSCT). Although ABO incompatibility is not considered a contraindication in alloHSCT, its clinical outcomes are still doubtful. In this study, we analyzed the neutrophil and platelet recovery, graft versus host disease (GVHD), relapse rate, mortality rate, non-relapse mortality and survival in patients who underwent alloHSCT.Materials and methodsTwo hundred and sixty four patients with hematological malignant diseases, aplastic anemia and inborn errors of metabolism or the immune system that received an alloHSCT in our HSC transplant center between the years of 2001 and 2018 were evaluated.ResultsIndications for alloHSCT included both hematological malignancies (n = 233), aplastic anemia (n = 25) and benign conditions (n = 6). Of these donor recipient pairs, there were 189 (71.6%) matches, 36 (13.6%) major, 29 (11%) minor and 10 (3.8%) bidirectional ABO mismatches. The seventy-four (41.6%) of the ABO match and 27 (38.6%) of the ABO mismatch patients developed GvHD. The 5-year overall survival (OS) was ABO match group and ABO mismatch group were 65% and 73%, respectively (p = 0.36). The 5-year diasease free survival (DFS) for ABO match group and ABO mismatch group were 60% and 69%, respectively (p = 0.17).ConclusionIn conclusion, this study showed that ABO mismatch did not seem to have a significant effect on major outcomes after alloHSCT, such as developing GVHD, relapse rate, mortality rate, DFS and OS. ABO incompatibility did not lead to delayed platelet and neutrophil engraftment after alloHSCT.     

Red blood cell alloimmunization among sickle cell Kuwaiti Arab patients who received red blood cell transfusion

BACKGROUND: Sickle cell disease (SCD) is common in the Arabian Gulf region. Most cases require a red blood cell (RBC) transfusion, increasing the potential for RBC alloantibody development. The incidence of RBC alloimmunization among Kuwaiti Arab SCD patients is not yet known. This study retrospectively assessed the effect of using two different matching protocols on the incidence of alloimmunization among multiply transfused Kuwaiti Arab SCD patients.
STUDY DESIGN AND METHODS: A total of 233 Kuwaiti Arab SCD patients were divided into two groups: Group 1 (n = 110) received RBC transfusion through standard ABO- and D-matched nonleukoreduced blood; Group 2 (n = 123) received RBCs matched for ABO, Rh, and K1 poststorage-leukoreduced blood. Multivariate analysis was performed on the factors associated with RBC alloimmunization and antibody specificity.
RESULTS: Sixty-five percent of patients in Group 1 developed clinically significant RBC alloantibody with an increased prevalence in females; in patients in Group 2, 23.6% developed RBC alloantibodies (p = 0.01). In Group 1, 72 patients (65.5%) had alloantibodies directed against Rh and Kell systems (p = 0.01). Multivariate analysis further confirmed the results, showing that blood transfusion type and sex have significant effects on the rate of alloimmunizations.
CONCLUSION: This study confirms the importance of selecting RBCs matched for Rh and Kell to reduce the risk of alloimmunizations among Kuwaiti Arab SCD patients.     

Non-Alloimmune Mechanisms of Thrombocytopenia and Refractoriness to Platelet Transfusion

Refractoriness to platelet transfusion is a common clinical problem encountered by the transfusion medicine specialist. It is well recognized that most causes of refractoriness to platelet transfusion are not a consequence of alloimmunization to human leukocyte, platelet-specific, or ABO antigens, but are a consequence of platelet sequestration and consumption. This review summarizes the clinical factors that result in platelet refractoriness and highlights recent data describing novel biological mechanisms that contribute to this clinical problem.     

Passive anti-C acquired in the setting of Rh immune globulin administration following Rh mismatched apheresis platelet transfusion: A case series

Rh immune globulin (RhIG) may be administered to Rh(D)-negative recipients of Rh(D)-positive platelet (PLT) transfusions to mitigate anti-D alloantibody formation. We report a series of seven patients in which anti-C was detected as a result of RhIG administered as immunoprophylaxis following Rh-mismatched apheresis PLT transfusion, persisting for a range of 27 to 167 days post-RhIG. The passively transferred anti-C antibodies created complexities for subsequent transfusion support. Based on these challenges, in combination with emerging evidence supporting an extremely low anti-D alloimmunization risk following Rh-mismatched apheresis PLTs, we have changed our practice and now limit RhIG immunoprophylaxis in this setting to women of reproductive age. In summary, the blood bank and apheresis communities should be aware that passive transfer of non-D antibodies is possible following RhIG administration. This phenomenon represents a compelling reason to consider the risk/benefit ratio of RhIG and to limit its use to situations in which it is clinically necessary.     

Absence of anti-D alloimmunization in hematologic patients after D-incompatible platelet transfusions

BACKGROUND: Rh antigens are not present on the platelet surface. However, platelet concentrates may contain enough RBCs to elicit an anti-D response. Thus, D status must be considered in platelet transfusion. In immunosuppressed patients, frequencies of D alloimmunization of up to 19 percent have been previously reported. STUDY DESIGN AND METHODS: Here a prospective study is reported in which 22 D- patients with hematologic disease received D+ platelet transfusions. Platelet concentrates were prepared from whole-blood donations according to the buffy coat method and were pooled before administration. The antibody screen test to detect anti-D was performed by LISS- IAT using the gel test. RESULTS: Our series comprises 22 immunosuppressed D+ patients with a median age of 56 years (range, 23-79). The patients received 121 D-incompatible pooled platelet transfusions. The mean +/- SD of RBC content was 4.17 +/- 1.74 mL. None of the 22 patients developed detectable anti-D after a median follow-up of 8 weeks (range, 1-37). CONCLUSION: The risk of D alloimmunization is low in patients with hematologic disease after D-incompatible platelet transfusions using platelet concentrates prepared by the buffy coat method.     

Delayed massive immune hemolysis mediated by minor ABO incompatibility after allogeneic peripheral blood progenitor cell transplantation

BACKGROUND: Bone marrow transplantation with minor ABO incompatibility may be followed by moderate delayed hemolysis of the recipient's red cells by donor-derived ABO antibodies. This reaction may be more severe after transplantation of peripheral blood progenitor cells (PBPCs). CASE REPORT: A 16-year-old boy underwent an allogeneic PBPC transplant from his HLA-mismatched mother as treatment for acute myeloblastic leukemia that had proved resistant to induction chemotherapy. Transfusion of the unmanipulated PBPCs proceeded without any complication, despite the difference in ABO blood group (donor, O Rh-positive; recipient, A Rh-positive). On Day 7, a rapid drop in hemoglobin to 4 g per dL was observed, which was attributed to a massive hemolysis. All the recipient's group A red cells were destroyed within 36 hours. This delayed and rapidly progressive hemolytic anemia was not associated with the transfusion of the donor's plasma. Rather, the anti-A titer increased in parallel with marrow recovery, which suggested an active synthesis of these antibodies by immunocompetent cells from the donor against the recipient's red cells. The mother's anti-A titer was retrospectively found to be 2048. Her unusually high titer is probably due to prior sensitization during pregnancies. On Day 12, the patient developed grade IV graft-versus-host disease, which proved resistant to all treatments instituted and led to his death on Day 35. CONCLUSION: PBPC transplantation with minor ABO incompatibility may be associated with significant risk of massive delayed hemolysis.     

Exchange transfusion the hard way: massive hemolysis following transplantation of bone marrow with minor ABO incompatibility

BACKGROUND: Bone marrow transplantation using donors with minor ABO incompatibility may result in the rapid production of donor-derived red cell isohemagglutinins, causing hemolysis of recipient red cells. CASE REPORT: The transplant of sibling-donor marrow with minor ABO incompatibility (group O donor marrow to group A recipient), using FK- 506 as an immunosuppressant to prevent graft-versus-host disease, is reported. Following early myeloid engraftment, the recipient developed hemolysis of her entire A red cell population between Day 8 and Day 11. This brisk hemolytic anemia was due to rapid donor lymphoid engraftment that resulted in the explosive production of donor-derived anti-A. CONCLUSION: Patients undergoing the transplantation of marrow from donors with minor ABO incompatibility in which the donor cells can produce isohemagglutinins against the recipient's red cells must be kept under vigilant observation for the possible development of severe hemolysis, particularly in the setting of profound T-cell suppression without B-cell suppression.     

Severe hemolysis resulting from D incompatibility in a case of ABO-identical liver transplant

BACKGROUND: Hemolysis due to D incompatibility in the setting of liver transplantation is less frequent than that associated with ABO incompatibility, but can represent an equally adverse event. Approximately 10 percent of ABO-compatible liver transplants involve a D- donor and a D+ recipient. CASE REPORT: A case of severe D incompatibility resulting from liver transplantation in a 50-year-old O Rh+ man with end-stage liver disease who received an O Rh- liver allograft is reported. A declining hemoglobin level complicated the patient's postoperative course with laboratory evidence of anti-D-mediated hemolysis. Investigations revealed that the transplanted liver was from a female O Rh- donor with detectable antibodies against D, C, and K. The severity of the hemolytic anemia was such that the patient required two separate red blood cell (RBC) exchanges and intermittent RBC transfusions over the course of almost a year. In addition to the use of RBCs negative for D, C, and K, the patient underwent a variety of B-cell suppressive therapies including glucocorticosteroids, mycophenolate mofetil, and rituximab. A normalization of hemoglobin levels and a decrease in serum bilirubin did not occur until after a splenectomy on postoperative Day 321. CONCLUSION: This represents the sixth and most severe case reported of hemolysis resulting from D incompatibility in liver transplantation. When unexpected serologic findings are identified in a transplant recipient, obtaining more information on the donor may help guide transfusion support.     

Absence of D alloimmunization in D- pediatric oncology patients receiving D-incompatible single-donor platelets

BACKGROUND: Guidelines are lacking for prophylaxis against D alloimmunization after D-incompatible platelet transfusion. A rational basis for the application of prophylaxis would be beneficial for institutions in which inventory constraints demand the administration of large numbers of D-incompatible platelets. STUDY DESIGN AND METHODS: A retrospective analysis was performed of all D-incompatible platelet transfusions administered at a pediatric research hospital over a 1.5-year period. Patients exclusively received single-donor WBC-reduced platelets and did not receive RhIg immunoprophylaxis. Numbers, source, ABO type, duration of serologic follow-up, and level of RBC contamination of D-incompatible transfusions were analyzed. All positive D serologies in the institution over a 3.5-year period were examined to determine cause and potential association with platelet transfusion. RESULTS: Thirty-five patients not receiving bone marrow transplant and seven bone marrow transplant patients received 490 and 255 D-incompatible transfusions, respectively, over 1.5 years. Patients had various diagnoses, predominantly malignancies. Seventy-nine percent of D-incompatible transfusions were ABO compatible. An estimated 2300 incompatible transfusions were performed over 3.5 years. No case of D alloimmunization was detected. CONCLUSIONS: D immunoprophylaxis is generally unnecessary in pediatric oncology patients receiving D-incompatible, WBC-reduced, single-donor platelets not visibly contaminated by RBCs. Further studies to validate these observations in the pediatric population and to extend them to other population groups are warranted.     

Impact of peri-transplant RBC transfusion and ABO incompatibility on acute graft-versus-host disease in pediatric hematopoietic stem cell transplant patients

It is well known that stem cell transplantation is curative for many diseases; however, graft versus host disease (GVHD), which is a common posttransplant complication, has still a substantial place among the causes of transplant-related morbidity and mortality.The association between ABO incompatibility and GVHD is controversial. There is also limited available data about the association between blood component transfusions during the peritransplant period and GVHD development in the pediatric setting.Hence, we retrospectively evaluated both the impact of ABO-mismatch and transfusions of RBC and platelets between day -7 pre-transplant and +30 post-transplant to the development of acute GVHD (aGVHD). We analyzed 139 allotransplants in 133 patients who were transplanted by myeloablative conditioning. Fifty-one patients out of 133 (36.7 %) were found to have aGVHD within +100 days post-transplantation. Of them 40 patients had grade I-II and 11 patients had grade III-IV aGVHD. Increased risk of aGVHD is associated with ABO minor mismatch (p: 0.030). Nevertheless, there was no association between ABO mismatch and severity of aGVHD. The median number of RBC transfusions in aGVHD patients was higher than the number of transfusions in patients without aGVHD; however, the difference was not statistically significant (p: 0.11). Platelet transfusion numbers were statistically similar between aGVHD patients and the patients without aGVHD (p: 0.79).In conclusion, major and bi-directional ABO-incompatibility between donors and recipients, and RBC and platelet transfusions between day -7 pretransplant and day +30 post-transplant do not contribute to aGVHD development in children undergoing HSCT by myeloablative conditioning, while ABO minor mismatch is associated with the development of aGVHD.     

Low rates of anti-recipient isohemagglutinins in ABO incompatible hematopoietic stem cell transplants

IntroductionIsohemagglutinins occur naturally and form in an 'opposite' (antigen-negative) pattern to a patient’s ABO blood type. Patients undergoing minor and bidirectional ABO incompatible hematopoietic stem cell transplantation (HSCT) may demonstrate detectable antibodies against their native blood type. In this study, we sought to characterize the rates of such antibody formation and evaluate the clinical significance of our findings.Materials and MethodsAn internal database of HSCT patients at an academic medical center was queried for ABO incompatible transplant patients from 2009-2019. Serum typing results, clinical histories, and laboratory data were compiled and reviewed.ResultsA total of 182 minor and bidirectional ABO incompatible HSCT patients were identified. Anti-recipient isohemagglutinins were found in 9% (16/182) of the HSCT patients. The rate was higher in patients with minor incompatibility (12%: 15/127) versus bidirectional ABO incompatibility (2%: 1/55) (p = 0.04). No anti-recipient isohemagglutinins were identified in umbilical cord HSCT patients (0%: 0/7). Serologic agglutination reactions of recipient isohemagglutinins were overall mostly weak (13/16 weak + to 1+). There was a trend towards a higher rate of acute graft-versus-host-disease in patients with anti-recipient isohemagglutinins compared to those without (75% vs. 53%; p = 0.12), though not statistically significant. Rates of alloimmunization to minor red cell antigens were similar between the two groups. Few patients showed laboratory evidence of hemolysis at 12 months follow up.Discussion and conclusionsAnti-recipient isohemagglutinins occur at low rates in ABO incompatible HSCT and are significantly more common in minor ABO incompatible transplant compared to bidirectional transplants. Larger cohort studies are needed to better understand the relationship between anti-recipient isohemagglutinins and HSCT outcomes.     

TRANSFUSION PRACTICE: Toward extended phenotype matching: a new operational paradigm for the transfusion service

BACKGROUND: Conventional pretransfusion testing uses hemagglutination to ensure donor‐recipient compatibility for ABO/D status and recipient alloantibodies. While screening large numbers of donor units for multiple antigens by hemagglutination is impractical, novel methods of DNA analysis permit the rapid determination of an extended human erythrocyte antigen (xHEA) phenotype. A prospective observational study was conducted at four hospital transfusion services to test an alternative paradigm of identifying xHEA‐typed units for patients in three cohorts by utilizing DNA analysis and a novel inventory management model. STUDY DESIGN AND METHODS: xHEA typing of recipient samples and donor units of known ABO/D status was performed by HEA analysis (BeadChip, BioArray Solutions). xHEA‐typed units were assigned to pending transfusion requests using an inventory management system designed to simulate blood order processing. The fraction of requests fulfilled, or “fill fraction” (FF) was determined at four levels of matching stringency. RESULTS: For alloimmunized patients, all but one participating site observed an FF of more than 95% when matching for ABO, D, and known alloantibodies and an FF of more than 90% when additionally matching for C, c, E, e, and K; the site handling the most challenging requests still observed FFs of 62 and 51%, respectively. FF was found to correlate positively with the ratio of available donor units to units requested and negatively with the degree of recipient alloimmunization. CONCLUSION: This study demonstrates that substantial fill fractions can be achieved by selecting existing donor units for xHEA analysis and operating an inventory management system for efficient allocation of units to recipients.     

Prevention of D sensitization after mismatched transfusion of blood components: toward optimal use of RhIG

Transfusion of D+ red blood cells (RBCs) into D- recipients, whether through whole blood, RBC, or platelet (PLT) transfusion, can lead to alloimmunization with associated risks of hemolytic reactions from subsequent mismatched transfusion. The incidence of D alloimmunization in various transfused patient populations may be different from that reported in normal subjects or in pregnancy, but prevention of D alloimmunization after mismatched transfusion can be achieved using RhIG. An optimal approach to the use of RhIG, however, has not been identified for the United States. Case histories and studies of volunteers reported over the past 40 years have established that alloimmunization to mismatched RBC transfusion can be successfully prevented with a dose of 20 microg of RhIG per 1 mL of D+ RBCs (per 2 mL of whole blood) when given within a window of opportunity that extends to at least 72 hours. Evidence from prospective studies of RhIG as a therapy for immune thrombocytopenic purpura suggests that such doses can be tolerably given by intravenous injections over short periods, with adverse event rates minimized when pretransfusion medication is given. For mismatched PLT transfusions, the lowest dose of standard preparations of RhIG (e.g., 125 or 300 microg) should be sufficient to prevent alloimmunization given the small D+ RBC volumes involved. This article reviews how our understanding of prevention of alloimmunization in mismatched transfusion has progressed over the years and outlines some practical considerations based on the currently available evidence.     

儿童患者ABO血型不合单采血小板的输注

目的对儿童患者ABO血型不合单采血小板输注进行分析,探讨供受者间血小板ABO血型不同输注的可能性,以期提高患儿单采血小板输注的有效性。方法选择上海儿童医学中心单采血小板ABO血型不合输注的患儿111例,计算输注后24h血小板计数、纠正增加指数（CCI）,采用Х^2检验分析ABO血型不同单采血小板的输注疗效。结果儿童患者中,ABO血型不合单采血小板输注总有效率为78．4％,其中主侧相合的输注有效率为77．4％,次侧相合为87．8％,主次不合为37．5％。Х^2=10．06,P〈0．01,三组不相合的输注效果的差异有统计学意义。结论儿童患者中ABO血型不同的单采血小板输注应尽量选择次侧相合（血浆相容）的血小板。