Study on relationship between platelet transfusion efficacy and KIR-HLA receptor-ligand compatibility / 中国输血杂志

【Objective】 To study the correlation between platelet transfusion efficacy and KIR receptor-HLA ligand. 【Methods】 Thirty-three leukemia patients with positive HLA antibody were tested for cross-matching with donor platelets. Platelets from suitable donors were selected for transfusion, and the 24-hour platelet corrected count increment (CCI) was used to determine the transfusion effect. KIR and ligand genotyping were performed on blood samples from patients and donors by PCR-SSP method, and the relationship between platelet transfusion effects and KIR receptor-HLA ligand was analyzed. 【Results】 In 74 occasions of platelet transfusion, 42 were ineffective and 32 were effective. When the donor had C2 gene and HLA-B Bw4-80T gene, the frequency of ineffective platelet transfusion in the recipient was 69.0% (29/42) and 52.4% (22/35), respectively, which was significantly higher than that in the effective group [25.0% (8/32) and 25.0% (8/32)]. When the donor had C1 gene, and the frequency of effective platelet transfusion in the recipient was 100.0%(32/32), which was higher than that in the ineffective group [83.3%(35/42)]. When the recipient-donor matching mode was KIR2DL1-C2 and KIR3DL1-(HLA-B Bw4-80T), the frequency of ineffective platelet transfusion was 69.0%(29/42) and 40.5%(22/42),higher than that of the effective group [25% (8/32) and 18.8% (6/32)]. When the recipient-donor matching model was KIR2DL3-C1, the rate of effective platelet transfusion in 32 patients (100.0%), which was higher than that (35 patients 83. 3%) in the ineffective group. When the mismatch mode of recipient iKIR+donor HLA ligand receptor was KIR2DL1-C2, the frequency of effective platelet transfusion in the recipient was 78.1% (25/32), which was much higher than that in the ineffective group [31.0% (13/42)]. When the mismatch mode was KIR3DL1-(HLA-B Bw4-80T), the rate of effective platelet transfusion in the recipient was 68.8% (22/32), which was higher than that in the ineffective group (42.9%, 18/42). The difference between the above groups was statistically significant(P<0.05). 【Conclusion】 HLA-C1 and HLA-C2 genes are the key factors affecting the efficacy of platelet transfusion.For platelet refractorines, HLA-C1 is the protective gene, while HLA-C2 and HLA-B Bw4-80T are the susceptible genes. The recipient iKIR+donor HLA ligand receptor model may play an important role in platelet refractoriness.

Anticuerpos antiplaquetarios en pacientes cubanos en espera de trasplante renal / Platelet antibodies in cuban patients waiting for renal transplantation

Introducción: Los antígenos específicos de plaquetas, conocidos como antígenos de plaquetas humanas (HPA, del inglés human platelet antigens), se incluyen dentro del espectro de antígenos de histocompatibilidad no-HLA, debido a que los anticuerpos anti-HPA participan en el rechazo del trasplante, además de ser causa del fenómeno de refractariedad plaquetaria. Objetivo: Caracterizar los anticuerpos contra antígenos específicos de plaquetas en pacientes cubanos en espera de trasplante renal. Métodos: Se investigaron muestras de sangre de 901 pacientes mediante la técnica de inmovilización de antígenos plaquetarios con anticuerpos monoclonales. Resultados: En 78 pacientes se detectaron anticuerpos anti-HPA, que en el 87,17 por ciento reconocían los antígenos presentes en el complejo GP-IIb/IIIa. Estos anticuerpos fueron del tipo IgG en el 78,2 por ciento, IgA en el 11,53 por ciento e IgM en el 46,15 por ciento. Conclusiones: En pacientes cubanos en espera de trasplante renal son frecuentes los Ac anti-HPA, en su mayoría del tipo IgG dirigidos contra antígenos presentes en el complejo GP-IIb/IIIa(AU)

Introduction: Platelet-specific antigens, known as human platelet antigens (HPA), are included within the spectrum of non-HLA histocompatibility antigens, because HPA antibodies participate in the rejection of transplantation, besides being a cause of the phenomenon of platelet refractoriness. Objective: To characterize antibodies against platelet-specific antigens in Cuban patients awaiting kidney transplantation. Methods: The technique monoclonal antibodies immobilized platelets antigens was applied to blood samples from 901 patients. Results: HPA antibodies were detected in 78 patients, which in 87.17 percent recognized the antigens present in the GP-IIb / IIIa complex. These antibodies were in 78.2 percent of the IgG class, in 11.53 percent IgA and IgM in 46.15 percent. Conclusions: HPA antibodies, mostly of the IgG class and directed to antigens present in the GP-IIb/IIIa complex, are common in Cuban patients awaiting kidney transplantation(AU)

Allele and haplotype frequencies of human platelet and leukocyte antigens in platelet donors / Frequência alélica e haplotípica dos antígenos plaquetários e leucocitários humanos em doadores de plaquetas

ABSTRACT Objective To described the allele and haplotype frequencies of human leukocyte antigen genes at the -A, -B loci and human platelet antigen genes for human platelet antigen systems 1 to 9, 11 and 15 in blood. Methods We included 867 healthy unrelated volunteer donors who donated platelets between January 2011 and December 2014. Microarray genotyping was performed using a BeadChip microarray. Medium resolution typing of the human leukocyte antigen at loci A and B was carried out using sequence-specific oligonucleotide probe hybridization. We used multivariate analysis and our human leukocyte antigen population was compared to data from the United States national bone marrow donor program. Human platelet antigen results were compared to a literature review and data from around the world. Results Our human leukocyte antigen haplotype results were more similar to those of hispanics, followed by caucasians. Likewise, our human platelet antigen sample is more similar to those of Argentina, Rio Grande do Sul and Italy. Conclusion This was the first article that discusses human platelet antigen and human leukocyte antigen data together. Rare genotypes or antibody associations can make patient management difficult. A blood bank with genotyped donors allows for optimal transfusion and can contribute to better results. Our information can serve as basis for a database of platelet antigen polymorphisms.

RESUMO Objetivo Descrever as frequências alélicas e haplotípicas de genes dos antígenos leucocitários humanos nos loci -A,- B e dos antígenos plaquetários humanos para os sistemas HPA-1 a 9, 11 e 15. Métodos Foram incluídos 867 doadores voluntários, saudáveis, não relacionados, que doaram plaquetas por aférese entre janeiro de 2011 e dezembro de 2014. A genotipagem foi realizada usando microarray BeadChip. A tipificação de resolução intermediária dos antígenos leucocitários humanos loci A e B foi realizada por meio de hibridização com sonda para oligonucleotídeos por sequência específica. Utilizamos análises multivariadas e o antígeno leucocitário humano de nossa população foi comparado com a do programa nacional de doadores de medula óssea norte-americano. Já os resultados dos antígenos plaquetários humanos foram comparados à revisão da literatura e a dados de populações de outros países. Resultados Os resultados do haplótipo de antígenos leucocitários humanos são mais parecidos com os dos hispânicos, seguidos dos caucasianos. Igualmente, a amostra de antígenos plaquetários humanos foi mais semelhante às da Argentina, do Rio Grande do Sul e da Itália. Conclusão Este foi o primeiro artigo a discutir antígenos plaquetários e leucocitários humanos simultaneamente. Genótipos raros ou associações de anticorpos podem dificultar o manejo clínico do paciente. Um banco de sangue com doadores genotipados permite um melhor resultado e transfusão possíveis. Estas informações podem servir de base para um banco de dados sobre polimorfismos de antígenos plaquetários.

Refractariedad plaquetaria: acercamiento al diagnóstico / Platelet refractoriness: approaches to diagnostic

La refractariedad plaquetaria representa un problema clínico significativo que complica la transfusión de plaquetas, está asociada con resultados clínicos adversos y elevados costos hospitalarios. Se define como una respuesta inadecuada a la transfusión de plaquetas después de dos transfusiones consecutivas. Las causas no inmunes son las más frecuentes y las primeras que deben ser investigadas en el diagnóstico de refractariedad plaquetaria. La refractariedad de causa inmune está mediada por anticuerpos contra antígenos HLA o HPA. Si se identifican los anticuerpos, existen tres formas de identificar unidades de plaquetas compatibles: el tipaje HLA, la prueba cruzada y la predicción de la especificidad del anticuerpo. Se recomienda el empleo de plaquetas fresca ABO idénticas y fenotipadas para eliminar estas variables potenciales como causa de refractariedad(AU)

Platelet refractoriness represent a significant clinical problem that complicates the provision of platelet transfusions, it is associated with adverse clinical outcomes and increases health care costs. Platelet refractoriness is defined as an inadequate response to platelet transfusions after two sequential transfusions. Nonimmune causes are the most likely and the first that should be explored in the diagnosis of platelet refractoriness. Immune-mediated platelet refractoriness is cause by antibodies to human leukocyte antigens (HLAs) and/or human platelet antigens. If antibodies are identified, there are 3 strategies for identifying compatible platelet units: HLA matching, crossmatching, and antibody specificity prediction. It is recommended to use fresh and ABO-matched platelets in the diagnosis of platelet refractoriness to eliminate these potential variables as causes of refractoriness(AU)

Korean Red Cross HLA-Matched Platelet Donor Registry / 대한수혈학회지

BACKGROUND: Transfusion of HLA-matched platelets is required when development of platelet refractoriness occurs after repeated platelet transfusion. This study was conducted to establish a HLA-matched platelet donor registry to supply matched platelets to patients who develop platelet refractoriness. METHODS: HLA-matched platelet donors were recruited among plateletpheresis donors. HLA-A and HLA-B antigen types of recruited donors were tested using a polymerase chain reaction-sequence specific oligonucleotide probe method. RESULTS: A total of 1,029 plateletpheresis donors were recruited. HLA-A and HLA-B antigen frequencies of recruited donors were similar to those of previously reported HLA antigen frequencies of Koreans. During the study period, a patient with platelet refractoriness recovered after receiving six units of HLA-matched platelets. CONCLUSION: During this study 1,029 donors were registered as HLA-matched platelet donors and a patient with platelet refractoriness received HLA-matched platelets using this registry. Supply of HLA-matched platelets will be facilitated by continuous expansion of the number of registered HLA-matched platelet donors, development of a program for management and searching for HLA-matched donors, and establishment of a request-supply system between hospitals and the Korean Red Cross through further studies.

An Evaluation of Platelet Transfusion Response Using HLA Crossmatch-compatible Donors in Patients with Platelet Refractoriness / 대한진단검사의학회지

BACKGROUND: Majority of immune-mediated platelet refractoriness is caused by HLA alloimmunization and can be effectively managed by HLA-matched platelet transfusions. However, HLA class I-typed large-sized donor registry has not been well established in Korea. We evaluated the effectiveness of platelet transfusion using HLA crossmatch-compatible donors without HLA typing. METHODS: Sixteen patients showing platelet refractoriness to random donor platelets (1 hr corrected count increment [CCI] 60%) were crossmatched with 78 platelet apheresis-eligible donors using National Institute of Health (NIH) and anti-human globulin (AHG) lymphocytotoxicity methods. NIH negative/AHG negative and NIH negative/AHG positive donors were selected as best and second choice donors, respectively. RESULTS: Eleven patients (11/16, 69%) could find NIH-crossmatch negative donors and 27 donors (27/78, 35%) belonged to the best donors. To 8 patients, 32 apheresis platelet products from 19 donors were transfused. The mean 1 hr and 24 hr CCI values from the best donors were significantly higher than those from random donors (17,893 vs 2,358, P=0.003; 8,292 vs -614, P<0.001), whereas such differences were not observed for those from the second choice donors. Platelet storage time was inversely correlated with CCI values and platelets stored < or =10 hr after collection gave significantly higher CCI values. Neither ABO match nor donor status (related vs unrelated) affected the transfusion effectiveness. CONCLUSIONS: Effective post-transfusion platelet increment using HLA crossmatch-compatible donors was attained in patients with platelet refractoriness due to HLA antibodies, and this method can be used effectively where HLA-typed platelet donor registry is not available.

General Anesthesia for Cesarean Section of a Parturient with Aplastic Anemia Refractory to Platelet Transfusion

Aplastic anemia is pancytopenia with bone marrow hypocellularity. The major risks to the pregnant women with aplastic anemia are hemorrhage and infection. Mortality during or after pregnancy is very high, especially thrombocytopenia complicated by platelet refractoriness, due to bleeding and sepsis. There is no therapeutic guideline for aplastic anemia with platelet refractoriness about cesarean section. A multidisciplinary approach to patients with aplastic anemia refractory to platelet transfusion is essential. Close consultation among the hematologist, anesthesiologist and obstetrician, and a management plan are important. We report the successful management of such a patient during cesarean section under general anesthesia.

A Case of Aplastic Anemia in Pregnancy Refractory to Platelet Transfusion / 대한산부인과학회지

Aplastic anemia is a rare complication of pregnancy that is associated with significant maternal and fetal morbidity and mortality. The relationship between aplastic anemia and pregnancy is not yet clear. Aplastic anemia in pregnancy is difficult to manage because the risk of bleeding and infection is high, especially in refractory to platelet transfusion. There is no therapeutic guide-line and prognosis for aplastic anemia in pregnancy refractory to platelet transfusion. We recently experienced one case of aplastic anemia in pregnancy refractory to platelet transfusion without no peripartum complication. So we report this case with brief review of the literature.

An Evaluation of HLA-matched Platelet Transfusion Effect in Patients with Platelet Refractoriness / 대한진단검사의학회지

BACKGROUND: Patients with platelet refractoriness as a result of human leukocyte antigen (HLA) alloimmunization can be effectively managed by transfusion of HLA-matched platelets. In this study, we have retrospectively evaluated the effect of HLA-matched platelet transfusion using a hospital based donor pool of 450 HLA typed donors. METHODS: For 17 patients showing platelet refractoriness to random donor platelets [1 hr corrected count increment (CCI) or =7, 500/microliter/m2) was obtained. HLA crossmatch (NIH method) negative patients showed a significantly higher platelet increment compared with crossmatch positive patients (23, 877 vs 10, 823; P=0.000). Although better transfusion effect was obtained in higher grade HLA match of A-B2U by selection of HLA compatible donors according to patients' HLA antibody specificities, an effective platelet increment was obtained in lower grade matches as well. Platelets transfused 24 hours (20, 325 vs 11, 417; P=0.029). CONCLUSIONS: Although many low grade matched donors were selected due to a relatively small size of HLA typed donor pool, effective platelet increments were obtained by selecting platelet donors on the basis of HLA antibody specificity.

In vivo survival of acid-treated platelets in HLA-immunized rabbits / 대한수혈학회지

BACKGROUND: Platelet refractoriness has been reported to occur in 30-70% of multitransfused patients. This can result by either immune or nonimmune mechanisms. The predominant immune cause of platelet refractoriness is alloimmunization to HLA class I antigens. Recently, acid-treated platelets have been used in a few patients with platelet refractoriness due to HLA alloantibodies. However, the effect of acid-treated platelets has not been consistent. The aim of this study was to evaluate the in vivo survival of acid-treated, HLA-eluted platelets in HLA-immunized rabbits. METHODS: For in vivo survival test, 14 New Zealand White rabbits were studied. Four rabbits were in the nonimmunized control and 10 were immunized by weekly transfusions of human pooled platelets for six weeks. The HLA-immunized group was separated into two groups with transfusion of acid-treated platelets and untreated platelets. The survival of transfused platelets in rabbits with immunization and control group was estimated by a flow cytometer using FITC-labeled anti-CD42a. We also examined the HLA re-expression in acid-treated platelets due to regeneration and adsorption of HLA from human plasma. RESLUTS: The half-life of untreated platelets in nonimmunized rabbits was 11.8 +/- 3.7 hr. The half-life of acid-treated platelets in rabbits with HLA antibodies was 9.5 +/- 5.5 hr and the half-life of untreated platelets in rabbits with HLA antibodies was 5.9 +/- 2.9 hr. The difference between untreated platelets in the nonimmunized control group and acid-treated platelets in rabbits with HLA antibodies was statistically insignificant (p=0.221). Re-expression of HLA-A,B,C by endogenous resynthesis occurred continuously, and after 24 hrs it reached 84% of pre-elution level. Adsorption of HLA antigens from human plasma was completed within four hrs. CONCLUSIONS: Acid-treated, HLA-eluted platelets may be applicable for the patients with refractoriness to platelet transfusion, especially, in case of unavailability of HLA-compatible donors and fatal bleeding such as intracranial hemorrhage and pulmonary hemorrhage. However, the post-transfusion increment of the platelet count could not be maintained over 24 hrs because of the endogenous resynthesis of HLA antigens.

Establishment of an HLA-matched Platelet Donor Registry for the Management of Patients with Platelet Refractoriness / 대한수혈학회지

BACKGROUND: Heavily transfused patients commonly become refractory to platelet transfusion. Patients with platelet refractoriness due to HLA alloimmunization need HLA-matched platelet transfusion. We have established an hospital-based donor registry of HLA-typed platelet donors for the first time in Korea and evaluated the possibility of HLA-matched platelet supplies. METHODS: A total of 450 donors were registered and typed for HLA class I (A, B, C) antigens. A computer program was developed and used for the donor registry and HLA-matched donor search. A simulation study was performed on the availability of HLA-matched platelets for 100 patients from a pool of 450 donors. The availability of HLA-matched and cross reactive epitope group (CREG)-matched donors were analysed for HLA-A, B antigens. The CREGs defined by Fuller, Rodey, and UCLA criteria were used. RESLUTS: Among 100 patients, 63% had HLA-identical or HLA-matched (match grade: A, B1U, B2U) donors with only a low number of donors (mean 1.4) available per patient. Including CREG-matches (match grade: B1X, B2UX, B2X), majority (98%) of the patients had HLA- or CREG-matched (match grade: A~B2X) platelet donors with a higher number of donors (mean 26.6~40.5 by different CREG criteria) available per patient. Majority (86-98%) of the patients had 20 or more A~B4X matched donors, and about two thirds (61-74%) of the patients had 20 or more A~B2X matched donors. However, the number of ABO-identical matched donors was less than 30% of the total HLA- or CREG-matched donors. CONCLUSION: We established an HLA-matched platelet donor registry and using a donor pool size of < 500 donors, attainable in an hospital-based donor registry, the possibility of HLA-matched platelet supplies was confirmed in this study. However, for more satisfactory and ABO-matched platelet supplies a larger pool size is needed.

The Frequency and Characteristics of the Platelet Refractoriness and Alloimmunization in Platelet Concentrate Multiple-Transfused Thrombocytopenic Patients / 대한혈액학회지

BACKGROUND: Understanding the cause for platelet refractoriness in a given patient is the critical step in determining the strategy for optimum management. The aim of this study was to establish the causes and frequency of platelet refractoriness as well as the incidence of anti- HLA antibodies and anti-platelet specific antibodies in multiple transfused thrombocytopenic patients. METHODS: Our study was based on 58 patients requiring platelet transfusions on at least three consecutive occasions from September 1997 to December 1997 in our hospital. The platelet refractoriness was defined as 18-24 hour post-transfusion corrected count increment (CCI) of less than 5,000. Enzyme immunosorbent assay (EIA), panel reactive antibody test (PRA) and Modified antigen capture ELISA (MACE) were applied for the detection of alloimmunization. RESULTS: Thirty-nine patients had episodes of refractoriness (67%). In 39 patients, poor response was seen in 38 patients (97%) with presence of non-immune factors known to be associated with platelet refractoriness. The total rate of alloimmunization was 31%, accounting for fourteen patients (24%) who had HLA antibodies, and four patients (7%) who had platelet specific antibodies. No patient had platelet-specific antibodies in addition to HLA antibodies. From our results, alloimmunization has shown a statistically meaningful relationship with CCI and the use of leukoreduction filtered blood components. CONCLUSION: Our data suggest that immune mechanisms are not the predominant cause of platelet refractoriness and HLA antibodies are produced separately with platelet-specific antibodies, as well as more frequently in alloimmunization.

Analysis of Factors Associated with Platelet Refractoriness / 대한수혈학회지

BACKGROUND: Platelet refractoriness is associated with immune and nonimmune factors. It has been shown that the incidence of platelet refractoriness caused by HLA alloimmunization is decreased by using of leukocyte-depleted blood components. The purpose of this study was to determine the incidence of platelet refractoriness in relation to the use of leukocyte removal filter and the relative importance of immune and nonimmune factors. METHODS: One hundred and eighty-five patients with thrombocytopenia, treated with multiple transfusion were classified into three groups according to use of leukocyte removal filters (group I: no filter, II: Asahi filter, III: Pall filter). Patients were considered to be refractory when the 20-hour posttransfusion corrected count increment (CCI) was less than 4.5 x 109/L on three subsequent platelet transfusions. Nonimmune factors analyzed were fever, sepsis, disseminated intravascular coagulation, splenomegaly, bone marrow transplantation, and administration of amphotericin-B. RESLUTS: The overall incidence of platelet refractoriness was 45% in group I, 44% in group II, and 47% in group III. In more than 90%, platelet refractoriness was associated with the presence of nonimmune factors. The incidence of platelet refractoriness presumably caused by alloimmunization was less than 5% and is much higher in aplastic anemia than in leukemia. Patients with pregnancy history developed platelet refractoriness with an increased incidence compared to patients without pregnancy history. CONCLUSION: This study revealed that nonimmune factors were predominant causes of platelet refractoriness regardless of transfusion of leukocyte-depleted blood components.