A "New" Infrequent Red Cell Antigen, Rd (Radin)

Five examples of a "new" blood group antibody, anti-Rd (Radin), are reported. The corresponding antigen, Rd, is infrequent and does not correspond to any other known "low-incidence" antigen. Family studies indicate that Rd is an autosomal dominant character which does not belong to the ABO, MNSs, Rh, Lutheran, Kell or Kidd blood group systems. Furthermore, the gene determining Rd is not closely linked to either the haptoglobin or red cell acid phosphatase loci. Anti-Rd caused mild to moderate hemolytic disease of the newborn in all five families and has appeared with the first pregnancy.     

Impact of Red Blood Cell Antigen Matching on Alloimmunization and Transfusion Complications in Patients with Sickle Cell Disease: A Systematic Review

Red blood cells (RBC) transfusion is critical in managing acute and chronic complications in sickle cell disease (SCD); however, it is complicated by RBC alloimmunization, iron overload, transfusion reactions and infection. Several reports documented an increased incidence of alloantibodies in transfused individuals with SCD, especially for Rh and Kell antigens. As a result, the National Institutes of Health Expert Panel and British Society for Haematology guidelines recommend primary matching for C/c, E/e and K antigens in addition to ABO/RhD for RBC transfusions. However, the evidence supporting these recommendations was cited as limited and understanding of alloimmunization in SCD is evolving. To examine the limitations of the evidence, we undertook a systematic review of evidence behind recommendations for limited and extended serologic and genotypic RBC antigen matching to reduce alloimmunization, autoimmunization and transfusion reactions. Searches of PubMed, Embase, Cochrane, and Web of Science databases using MeSH index and free text terms between 1976 through October 2015 and papers and captured through July 2016 through review references in papers, word of mouth, and ongoing Google Scholar and Medline Alerts identified 303 unique articles. Nineteen articles met inclusion criteria and were classified by the Oxford Centre Evidence Based levels of evidence. Strengthening the Reporting of Observational Studies in Epidemiology checklists were completed for 18 of the 19 studies. There were no prospective randomized controlled trials. Sixteen of the articles were cohort studies, two were cross-sectional studies, and one decision tree model examining costs. Low-quality evidence from observational cohort studies supports that alloimmunization prevalence can be decreased by extending serological RBC antigen matching. Transfusion reactions are generally poorly and inconsistently reported. There was no evidence reporting the effect prophylactic genotypic matching has on alloimmunization, autoimmunization or transfusion reactions. There were no studies comparing prophylactic genotypic matching to serologic matching. High-quality evidence was lacking to support clinical decision making regarding best transfusion practices. Multicenter prospective randomized clinical trials are needed to determine best strategies for reducing the rate of alloimmunization using serologic and genotypic matching.     

罕见的Lewis血型系统抗体1例

献血者,男,37岁.血型初步定为AB”型,复查时,反定型Ac、Bc、Oc均凝集.经 进一步检查,献血者DAT阴性,血清中有两种抗体存在,一种是Lewis血型系统同种抗-Le a,另一种抗体可被Le(a-b+)和Le(a+b-)细胞吸收并放散而不被Le(a -b-)细胞及自身细 胞吸收,所针对的抗原决定簇既存在于Le(a+)细胞上也存在于Le(b+)细胞上, 而不存在于L e(a-b-)细胞上,笔者认为这后一种抗体为一罕见的Lewis血型系统抗体,现报告如下.     

Red Blood Cell Antigen Genotyping for Sickle Cell Disease,Thalassemia, and Other Transfusion Complications

Since the discovery of the ABO blood group in the early 20th century, more than 300 blood group antigens have been categorized among 35 blood group systems. The molecular basis for most blood group antigens has been determined and demonstrates tremendous genetic diversity, particularly in the ABO and Rh systems. Several blood group genotyping assays have been developed, and 1 platform has been approved by the Food and Drug Administration as a “test of record,” such that no phenotype confirmation with antisera is required. DNA-based red blood cell (RBC) phenotyping can overcome certain limitations of hemagglutination assays and is beneficial in many transfusion settings. Genotyping can be used to determine RBC antigen phenotypes in patients recently transfused or with interfering allo- or autoantibodies, to resolve discrepant serologic typing, and/or when typing antisera are not readily available. Molecular RBC antigen typing can facilitate complex antibody evaluations and guide RBC selection for patients with sickle cell disease (SCD), thalassemia, and autoimmune hemolytic anemia. High-resolution RH genotyping can identify variant RHD and RHCE in patients with SCD, which have been associated with alloimmunization. In the future, broader access to cost-efficient, high-resolution RBC genotyping technology for both patient and donor populations may be transformative for the field of transfusion medicine.     

Management of a Pregnant Woman with Anti-Holley Alloantibody

Background

Holley (Hy) is a high-incidence antigen of the Dombrock blood group system (ISBT 014), present in almost 100% of most populations and more than 99% of Blacks. Since anti-Hy is an extremely rare antibody, data on its clinical relevance and in particular on a possible hemolytic disease of the fetus and newborn (HDFN) are scarce.

Case Report

The pregnant patient underwent two autologous whole blood collections at weeks 17 and 19 of gestation with cryopreservation. In our case autologous whole blood collection was well tolerated. There were no signs of HDFN in the healthy newborn.

Conclusion

Our case improves our understanding of anti-Hy alloantibodies during pregnancy. Additionally, autologous whole blood collection of RBC units with cryopreservation is a safe and feasible way to manage pregnancies in women with rare alloantibodies, when no compatible donor can be found.Key Words: Anti-Holley alloantibody, Hemolytic disease of the fetus and newborn, HDFN, Pregnancy     

Persistence and Efficacy of Second Generation CAR T Cell Against the LeY Antigen in Acute Myeloid Leukemia

In a phase I study of autologous chimeric antigen receptor (CAR) anti-LeY T-cell therapy of acute myeloid leukemia (AML), we examined the safety and postinfusion persistence of adoptively transferred T cells. Following fludarabine-containing preconditioning, four patients received up to 1.3 × 109 total T cells, of which 14–38% expressed the CAR. Grade 3 or 4 toxicity was not observed. One patient achieved a cytogenetic remission whereas another with active leukemia had a reduction in peripheral blood (PB) blasts and a third showed a protracted remission. Using an aliquot of In111-labeled CAR T cells, we demonstrated trafficking to the bone marrow (BM) in those patients with the greatest clinical benefit. Furthermore, in a patient with leukemia cutis, CAR T cells infiltrated proven sites of disease. Serial PCR of PB and BM for the LeY transgene demonstrated that infused CAR T cells persisted for up to 10 months. Our study supports the feasibility and safety of CAR–T-cell therapy in high-risk AML, and demonstrates durable in vivo ­persistence.     

Evaluation of Transfusion Practices in Noncardiac Surgeries at High Risk for Red Blood Cell Transfusion: A Retrospective Cohort Study

Perioperative bleeding is a major indication for red blood cell (RBC) transfusion, yet transfusion data in many major noncardiac surgeries are lacking and do not reflect recent blood conservation efforts. We aim to describe transfusion practices in noncardiac surgeries at high risk for RBC transfusion. We completed a retrospective cohort study to evaluate adult patients undergoing major noncardiac surgery at 5 Canadian hospitals between January 2014 and December 2016. We used Canadian Classification of Health Interventions procedure codes within the Discharge Abstract Database, which we linked to transfusion and laboratory databases. We studied all patients undergoing a major noncardiac surgery at ≥5% risk of perioperative RBC transfusion. For each surgery, we characterized the percentage of patients exposed to an RBC transfusion, the mean/median number of RBC units transfused, and platelet and plasma exposure. We identified 85 noncardiac surgeries with an RBC transfusion rate ≥5%, representing 25,607 patient admissions. The baseline RBC transfusion rate was 16%, ranging from 5% to 49% among individual surgeries. Of those transfused, the median (Q1, Q3) number of RBCs transfused was 2 U (1, 3 U); 39% received 1 U RBC, 36% received 2 U RBC, and 8% were transfused ≥5 U RBC. Platelet and plasma transfusions were overall low. In the era of blood conservation, we described transfusion practices in major noncardiac surgeries at high risk for RBC transfusion, which has implications for patient consent, preoperative surgical planning, and blood bank inventory management.     

An Antibody, in the Serum of a Wr(a+) Individual, Reacting with an Antigen of Very High Frequency

The serum of a Wr(a+) woman has been found to contain an antibody reacting with an antigen of very high incidence. Preliminary tests on the strength of the Wr^a antigen on the cells of the antibody former and the variation of reactions of the antibody with the cells of nonrelated Wr(a+) and Wr(a-) individuals suggest that the antibody may be detecting the antithetical antigen to Wr^a.     

N-硝基精氨酸甲酯抗C6脑胶质瘤细胞增殖的研究

目的探讨一氧化氮合酶(NOS)抑制剂N-硝基精氨酸甲酯(L-NAME)在C6脑胶质瘤细胞株生长中的作用.方法体外培养的C6胶质瘤细胞加入终浓度分别为50 μmol/L、100 μmol/L、150 μmol/L、200 μmol/L的L-NAME和胸腺核苷嘧啶(3H-TdR),48 h后进行细胞3H-TdR结合率的液相闪烁计数检测.结果L-NAME50 μmol/L、100 μmol/L、150 μmol/L、200 μmol/L组对C6细胞的抑制率分别为23.57%、38.38%、46.18%、52.39%;C6细胞3H-TdR结合率在100 μmol/L、150 μmol/L、200 μmol/L组有明显降低,与对照组相比差异显著(P＜0.01).结论NOS抑制剂L-NAME能抑制体外培养的C6胶质瘤细胞的增殖,并呈浓度依赖性,一氧化氮(NO)可能对C6胶质瘤有增殖刺激作用.     

A New Algorithm for a High Level of Protection Against Pacemaker-Mediated Tachycardia

Pacemaker-mediated tachycardia (PMT) is a well-known complication of DDD pacing. PMT needs a permeable V-A conduction and is usually initiated by a premature ventricular or atrial systole, artifact sensing, or misprogramming (long AV delay [AVD]). Today, protection against PMT is expected from pacemaker multiprogrammability. Unfortunately, this prevention is often ineffective; postventricular atrial refractory period (PVARP) must be prolonged, which limits the upper tracking rate and the patient capacity. The new Chorus ELA Medical DDD pacemaker provides classic protection against PMT (PVARP prolongation after premature V or A complex, magnet application, noise sensing), hut also automatically reduces an eventual PMT and adjusts AVD or PVARP for a high level of protection. The process is divided in four steps: (1) a sensing step for 16 cycles, with V-P conduction analysis; (2) confirmation of the presence of the PMT and analysis of V-A conduction time; (3) a termination step, by extending the PVARP after the following ventricular heart beat; and (4) in case of immediate recurrence of the tachycardia, reprogramming of the AVD and eventually of the PVARP. By first reducing AVD, before reprogramming PVARP, the pacemaker preserves point 2:1, providing a higher exercise capacity. This algorithm was successfully tested in three patients who had a permeable V-A conduction, without any adverse effect.     

Monitoring of Cell Death in Epithelial Cells Using High Frequency Ultrasound Spectroscopy

Spectral and wavelet analyses were performed on ultrasound radiofrequency (RF) data collected from centrifuged cell samples containing HEp-2 cells after induction of apoptosis by exposure to camptothecin. Samples were imaged at several time points after drug exposure using high-frequency ultrasound in the range from 10–60 MHz. A 20-MHz transducer with a f-number of 2.35 and a 40-MHz transducer with a f-number of 3 were used for collecting the RF data. Normalized power spectra were computed from the backscattered ultrasound signals within a region-of-interest (ROI) for further analysis. Spectral slopes, integrated backscatter coefficients (IBCs) and wavelet parameters were estimated as a function of treatment time to monitor acoustic property changes during apoptosis. Changes in spectral parameters were detected starting six hours after treatment and coincided with changes in corresponding histology. Throughout the course of chemotherapy, variation in estimates of the spectral slope of up to 35% were observed. During the treatment, IBCs increased by 400% compared with estimates obtained from the control samples. Changes in spectral parameters are hypothesized to be linked to structural cell changes during apoptosis. In addition, the sensitivity of a wavelet-based analysis to the ultrasonic assessment of cellular changes was investigated. Results of the wavelet analysis showed variations similar to the spectral parameters. Where values of the spectral slope decreased, estimates of the scaling factors increased. Because wavelet analysis preserves the signal–time localization, its application will be potentially beneficial for assessing treatment responses in vivo. The current study contributes toward the development of a non-invasive method for monitoring apoptosis as a measure of the success of chemotherapeutic treatment of cancer. (E-mail: Sebastian.Brand@gmail.com)     

The Strength of the T Cell Response Against a Surrogate Tumor Antigen Induced by Oncolytic VSV Therapy Does Not Correlate With Tumor Control

Cancer therapy using oncolytic viruses has gained interest in the last decade. Vesicular stomatitis virus is an attractive candidate for this alternative treatment approach. The importance of the immune response against tumor antigens in virotherapy efficacy is now well recognized, however, its relative contribution versus the intrinsic oncolytic capacity of viruses has been difficult to evaluate. To start addressing this question, we compared glycoprotein and matrix mutants of vesicular stomatitis virus (VSV), showing different oncolytic potentials for B16/B16gp33 melanoma tumor cells in vitro, with the wild-type virus in their ability to induce tumor-specific CD8⁺ T cell responses and control tumor progression in vivo. Despite the fact that wild-type and G mutants induced a stronger gp33-specific immune response compared to the M_M51R mutant, all VSV strains showed a similar capacity to slow down tumor progression. The effectiveness of the matrix mutant treatment proved to be CD8⁺ dependent and directed against tumor antigens other than gp33 since adoptive transfer of isolated CD8⁺ T lymphocytes from treated B16gp33-bearing mice resulted in significant protection of naive mice against challenge with the parental tumor. Remarkably, the VSV matrix mutant induced the upregulation of major histocompatibility class-I antigen at the tumor cell surface thus favoring recognition by CD8⁺ T cells. These results demonstrate that VSV mutants induce an antitumor immune response using several mechanisms. A better understanding of these mechanisms will prove useful for the rational design of viruses with improved therapeutic efficacy.     

Red Blood Cell Microparticles: Clinical Relevance

Summary

Microparticles are small phospholipid vesicles of less than 1 µm released into the blood flow by various types of cells such as endothelial, platelet, white or red blood cells. They are involved in many biological and physiological processes including hemostasis. In addition, an elevated number of microparticles in the blood is observed in various pathological situations. In the context of transfusion, erythrocyte-derived microparticles are found in red blood cell concentrates. Their role is not elucidated, and they are considered as a type of storage lesion. The purpose of this review is to present recent data showing that erythrocyte-derived microparticles most likely play a role in transfusion medicine and could cause transfusion complications.KeyWords: Ageing, Microparticles, Red blood cells, Red blood cell concentrates, Transfusion     

A Red Blood Cell Freezing Program for Massachusetts

A regular service for freezing, thawing and washing red blood cells was established at the Massachusetts Red Cross Blood Center in 1970. This was the culmination of many years of investigation by the American National Red Cross and was part of a nation-wide program to introduce frozen, thawed, washed red blood cells. Frozen red blood cells have the advantages of a prolonged dating period, freedom from major hepatitis risks, and negligible leukocyte, platelet and plasma content. The major disadvantages are the complexity of solutions and equipment and the high degree of quality control required. This leads to a five-to-tenfold increase in cost when compared to standard red blood cell preparations. If better recruitment methods and better liquid blood processing procedures are developed, the first two advantages of frozen red blood cells over standard refrigerated red blood cells would be lost. There are some patients who cannot tolerate ordinary red blood cells and can only be transfused with the frozen, thawed, washed product. In Massachusetts, the obligatory requirement for frozen red blood cells is approximately 100 units per day or less. Until better liquid blood processing methods and recruitment procedures are developed, the Massachusetts Red Cross Blood Program will need to continue expanding the output of frozen, thawed, washed red blood cells.     

粘附细胞作为APC提高MS淋巴细胞对髓鞘抗原增殖反应的探索

目的　比较粘附细胞作为APC能否较一般方法提高T细胞对神经髓鞘类抗原的增殖反应性和显示出MS对神经髓鞘类抗原的特异自身免疫反应特征。方法　选HLA DR15亚型MS和正常人外周血单个核细胞 ,体外培养。分别用一般T淋巴细胞增殖试验和富集粘附细胞法检测对人神经髓鞘、蛋白脂蛋白 (PLP)和碱性髓鞘蛋白(MBP)淋巴细胞增殖反应性。结果　富集粘附细胞法使MS组和对照组T淋巴细胞对神经髓鞘、PLP和MBP的增殖较标准法提高 (P <0 .0 5 ) ;使MS组以MBP和PLP的增殖反应较对照组的差别具有显著性的意义 ;而对TT无明显提高作用。结论　富集粘附细胞法可提高T淋巴细胞对神经髓鞘、PLP和MBP的增殖反应性 (MS和NC) ,多数情况使MS组和NC组的差别具有显著性的意义 ,对非髓鞘类抗原 (如TT)无这种作用。     

Recurrence of Melanoma Following T Cell Treatment: Continued Antigen Expression in a Tumor That Evades T Cell Recruitment

Clinical therapy with T cells shows promise for cancer patients, but is currently challenged by incomplete responses and tumor relapse. The exact mechanisms that contribute to tumor relapse remain largely unclear. Here, we treated mouse melanomas with T cell receptor-engineered T cells directed against a human peptide-major histocompatibility complex antigen in immune-competent mice. T cells resulted in significant tumor regression, which was followed by relapse in about 80–90% of mice. Molecular analysis revealed that relapsed tumors harbored nonmutated antigen genes, not silenced by promoter methylation, and functionally expressed surface antigen at levels equal to nontreated tumors. Relapsed tumors resisted a second in vivo T cell treatment, but regained sensitivity to T cell treatment upon retransplantation in mice. Notably, relapsed tumors demonstrated decreased levels of CD8 T cells and monocytes, which were substantiated by downregulated expression of chemoattractants and adhesion molecules. These observations were confirmed when using T cells specific for a less immunogenic, endogenous mouse melanoma antigen. We conclude that tumors, when exposed to T cell treatment, can relapse without loss of antigen and develop a milieu that evades recruitment of effector CD8 T cells. Our findings support the concept to target the tumor milieu to aid T cell therapy in limiting tumor relapse     

mPEG修饰红细胞Rh抗原稳定性的研究

本研究旨在探究mPEG修饰的红细胞Rh抗原的稳定性。利用红细胞膜蛋白SDS—PAGE电泳技术分析mPEG修饰后红细胞膜蛋白与mPEG结合情况，用红细胞血影凝集实验及40cCPD保养液保存的修饰红细胞与匹配血液体外混血实验，观察mPEG修饰后红细胞Rh抗原被遮蔽的稳定性。结果发现：不同保存时间的mPEG修饰的红细胞在模拟输血（即混血前后）的血型保持不变，同时mPEG修饰的红细胞在保存过程中游离血红蛋白水平正常，并且混血后经37℃孵育的mPEG修饰的红细胞游离血红蛋白水平低于不混合的修饰的红细胞。比较分析PEG特异的碘染和考马斯亮蓝染的显色图谱发现，特殊的碘染显示出mPEG与红细胞膜蛋白结合的条带，mPEG—SPA与红细胞膜蛋白结合后导致蛋白分子迁移速度发生改变。mPEG修饰的红细胞血影凝集实验证实，修饰红细胞在质膜裂损后mPEG仍有效地遮蔽抗原。结论：mPEG—SPA不论在红细胞膜蛋白被单独提取后，还是膜破损后以及存活状态下，均能与红细胞膜蛋白稳固结合。