Platelet alloantibodies in transfused patients

BACKGROUND: Patients receiving cellular blood components may form HLA antibodies and platelet-specific alloantibodies. STUDY DESIGN AND METHODS: Serum samples from a cohort of 252 patients with hematologic or oncologic diseases who are receiving cellular blood components were studied for platelet-reactive antibodies. Specificity of platelet alloantibodies was determined with a panel of typed platelets RESULTS: Platelet-reactive antibodies were detected in the sera of 113 patients (44.8% of 252), HLA antibodies in the sera of 108 (42.9%), and platelet-specific antibodies in the sera of 20 (8%). The following platelet-specific antibodies were identified: anti-HPA-5b (n = 10), anti-HPA-1b (n = 4), anti-HPA-5a (n = 2), anti-HPA-1a (n = 1), anti-HPA-2b (n = 1), anti-HPA-1b+5b (n = 1), and anti-HPA-1b+2b (n = 1). Fifteen sera from the 108 patients with anti-HLA (13.9%) contained additional platelet-specific alloantibodies, while in 5 sera, platelet-specific alloantibodies only were detected: anti-HPA-5b (n = 4) and anti-HPA-1a (n = 1). Of the 108 sera with HLA antibodies, 29 (26.9%) showed discordant results when studied with the lymphocytotoxicity test and the glycoprotein-specific immunoassay. Ten sera contained panreactive antibodies against platelet glycoproteins (GP) IIb/IIIa, GPIa/IIa, and/or GPIb/IX. Alloimmunization occurred in 58.3 percent of female patients with previous pregnancies, but in only 23.3 percent of those without previous pregnancies (p = 0.0049). CONCLUSION: Platelet alloantibody specificities in transfused patients (predominantly anti-HPA-5b and -1b with antigen frequencies <30% among whites) differ significantly from those observed in patients with neonatal alloimmune thrombocytopenia or posttransfusion purpura, in whom anti-HPA-1a (antigen frequency >95%) is the most prevalent specificity. HLA antibody detection yields discordant results when the lymphocytotoxicity assay and a glycoprotein-specific immunoglobulin-binding assay are used.     

Adverse reactions in patients transfused with cryopreserved marrow

Marrow is cryopreserved for use in autologous bone marrow transplants, but little is known of the incidence of reactions in patients transfused with these cryopreserved marrows. Reactions in patients transfused during a 4-year period with 134 autologous marrows cryopreserved in dimethyl sulfoxide (DMSO) were compared with those in patients transfused with marrow that had been collected from HLA-compatible donors and that had not been cryopreserved. Patients transfused with cryopreserved marrow had significantly more nausea (44.8 vs. 14.1%; p less than 0.0005), vomiting (23.9 vs. 8.5%; p less than 0.01), chills (31.3 vs. 1.4%; p less than 0.0005), and fever (17.9 vs. 0%; p less than 0.005) than patients transfused with fresh allogeneic marrow. The incidence of emesis correlated with the dose of DMSO received, but that of nausea did not. All cryopreserved marrows were cultured for bacteria at the time of transfusion and 17 (12.7%) were found to be positive. Only 1 of the 17 patients transfused with culture-positive marrow developed sepsis during the transplant course with the same organism that was present in the transfused marrow. Although the reactions in donors transfused with cryopreserved marrow were readily treated, this study suggests that the incidence of some reactions might be decreased by reducing the dose of DMSO transfused. Bacterial contamination of transfused marrow was a worrisome complication, and efforts should be made to improve marrow collection and processing techniques to minimize that risk.     

Direct laser trapping for measuring the behavior of transfused erythrocytes in a sickle cell anemia patient

Using a laser trap, we have studied the properties of erythrocytes from a sickle cell anemia patient (SCA) after receiving an intravenous blood transfusion, and a normal adult individual carrying normal adult hemoglobin. The hemoglobin type and quantitation assessment was carried out by high performance liquid chromatography (HPLC). We conducted an analysis of the size distributions of the cells. By targeting those erythrocytes in the overlapping regions of size distributions, we have investigated their properties when the cells are trapped and released. The efficacy of the transfusion treatment is also studied by comparing the relative changes in deformation and the relaxation-time of the cells in the two samples.OCIS codes: (000.2190) Experimental physics, (000.1430) Biology and medicine, (170.4520) Optical confinement and manipulation, (350.4855) Optical tweezers or optical manipulation     

Alloimmunization in transfused patients with constitutional anemias in Norway

Background and ObjectivesThe status of red blood cell alloimmunization in patients with constitutional anemias including hemoglobinopathies is not known in Norway. The study objective was to investigate the impact of a strategy based on phenotype-matching for C, c, E, e, K, Jka, Jkb, Fya, Fyb, S and s on alloimmunization.Materials and MethodsWe reviewed transfusions of 40 patients retrospectively using the computerized blood bank management system and medical records; including diagnosis, age at start of transfusion therapy, gender, number and age of packed red blood cell units transfused, follow-up time, phenotypes of the donors and patients, antigen-negative patients exposed to antigen-positive packed red blood cell units, transfusion reactions and alloantibody specificities.ResultsForty patients received 5402 packed red blood cell units. Alloimmunization frequency was 20 % for the whole group, being 7%, 25 % and 30 % in patients with sickle cell disease (n = 14), thalassemia (n = 16) and other conditions (n = 10), respectively. The alloantibodies detected were anti-E, -c, -C, -Cw, -K, -Jka and -Lua.ConclusionGood communication between the clinicians and the transfusion services is essential for successful management of patients with constitutional anemias. Providing full phenotype-matched units was not always possible. Extended pheno-/genotyping before the first transfusion and providing antigen-negative units for antigen-negative patients for at least C, c, E and K in every red cell transfusion would probably have reduced the alloimmunization rate. Non-phenotype-matched transfusions seem to be the main reason for alloimmunization. Finding markers for identifying responders prone to alloimmunization will ensure targeted transfusion strategies.     

清洗式自体回收血液的红细胞特点

背景：清洗式自体血液回输是将术野血经回收、抗凝、过滤、离心、浓缩、清洗后回输给患者的自体血液回输方式,在临床中已大量应用。
　　目的：归纳总结清洗式自体回收血液的红细胞特点,包括红细胞的回收率和红细胞压积,红细胞的形状、变形能力、血流动力学和体内生存期的变化,红细胞携氧及供氧能力的变化以及红细胞免疫以及其表面膜受体的变化。
　　方法：由第一作者检索1987年1月至2013年1月 PubMed数据及万方数据库相关文献,英文检索词为“Blood transfusion,autologus,blood preservation,erythrocytes”,中文检索词为“输血;自体;血液保存;红细胞”。计算机初检得到与清洗式自体回收血液的红细胞特点相关文献200篇文献,排除重复性研究,保留60篇做进一步总结分析。
　　结果与结论：由于受负压吸引、离心分离等机械力、各种受损组织及细胞释放的炎性递质和酶类以及激活的补体等因素的共同作用,回收红细胞有一定程度的破坏,所以血液回收机对红细胞的总回收率取决于采集时的回收率、贮存破损率和清洗时的丢失率。自体血液回收对红细胞的携氧能力无明显影响,即回收血红细胞具有与正常红细胞相同的携氧能力。红细胞在自身输血前后免疫功能和表面受体的数量有所下降,但优于库存2周的红细胞。研究提示应提高血液回收技术以降低红细胞免疫黏附功能下降程度。     

自体血贮存在不同温度时红细胞形态的变化

背景：输血指南指出：全血应在（4±2）℃贮存,血液一旦离开正确的贮存条件,即有发生细菌繁殖或丧失功能的危险,受血者输注后则会发生不同程度的输血反应或输注无效。 目地：利用显微镜观察自体血贮存在不同温度下红细胞形态的变化。 方法：40例急性等容血液稀释患者取血后贮存在ACD枸橼酸血袋,分别贮存在4 ℃和常温23 ℃,于放自体血后即刻、自体血贮存1,2,3,4,5,6 h分别取样涂片,利用显微镜观察红细胞形态变化,计算红细胞畸形率。随机选取6 h段常温组血样与有效期内的ACD库存血各6份进行pH、K＋、游离血红蛋白等对比及细菌培养。 结果与结论：4 ℃组和常温组在各时间点红细胞畸形率差异无显著性意义, 6 h段常温组血样pH、K＋、游离血红蛋白等均优于有效期内的ACD库存血,培养均无细菌生长。提示常温下自体血贮存6 h内回输给患者是可行的。     

Importance of extended blood group genotyping in multiply transfused patients

Blood group antigen systems are not limited to the ABO blood groups. There is increasing interest in the detection of extended blood group systems on the red cell surface. The conventional method used to determine extended blood group antigens or red cell phenotype is by serological testing, which is based on the detection of visible haemagglutination or the presence of haemolysis. However, this technique has many limitations due to recent exposure to donor red cell, certain drugs or medications or other diseases that may alter the red cell membrane. We aimed to determine the red cell blood group genotype by SNP real time PCR and to compare the results with the conventional serological methods in multiply transfused patients. Sixty-three patients participated in this study whose peripheral blood was collected and blood group phenotype was determined by serological tube method while the genotype was performed using TaqMan^® Single Nucleotide Polymorphism (SNP) RT-PCR assays for RHEe, RHCc, Kidd and Duffy blood group systems. Discrepancies were found between the phenotype and genotype results for all blood groups tested. Accurate red blood cell antigen profiling is important for patients requiring multiple transfusions. The SNP RT-PCR platform is a reliable alternative to the conventional method.     

Mathematical calculation of lifespan of transfused RBCs in sickle cell disease patients

Background

Transfusion of donor red blood cells (RBCs) remains an important part of management of sickle cell disease (SCD). However, the survival characteristics of transfused donor RBCs in SCD patients have not been well studied. We sought to calculate survival kinetics of transfused RBCs in SCD patients since it is unclear whether transfused RBCs get destroyed at faster rate as innocent bystander or persist longer due to decreased destruction capacity such as functional splenectomy.

The plasma turnover of transfused antithrombin concentrate in patients with acquired antithrombin deficiency

Antithrombin concentrate, prepared from human plasma, has been used as replacement therapy in 35 patients with acquired antithrombin deficiency. The inhibitory activity of the concentrate, measured by chromogenic assay, correlates well with the manufacturer's quoted activity. The mean in vivo recovery of the product was 0.0124 iu mL ⁻¹ per iu of antithrombin (AT) concentrate administered by kilogram body weight. The recovery was similar in all diagnostic groups studied and did not vary during the course of treatment. Consumption of the antithrombin concentrate was monitored by measuring the production of thrombin–antithrombin complexes and the loss of plasma antithrombin activity. The mean concentration of thrombin–antithrombin complexes was elevated (23 ng mL ⁻¹) at the time of admission to the intensive care unit and fell progressively over the next 4 days. The mean time for the decay of half the antithrombin activity was 23 h during the first 24 h of therapy and rose to 42.1 h after day 1. The recovery and half-life measurements are necessary to plan an appropriate dosage regimen for the administration of this antithrombin concentrate in acquired deficiency states.