Frequency of unexpected red blood cell antibodies in Nanjing

The development of unexpected red blood cell antibodies can significantly complicate transfusion therapy and result in more difficulties in cross-matching of blood. This study aimed to determine the occurrence rate of red blood cell alloimmunization in patients from Nanjing and the surrounding area. The antibody screening tests were carried out on 604 patients in Nanjing Red Cross Blood Center from January 2014 to December 2016, and the results were compiled and statistically analyzed. In the 604 patients, 483 cases revealed autoantibodies with or without underlying alloantibodies, while 121 patients had only alloantibodies in their serum. The overall frequency of alloimmunization was 32.5%. The most frequent antibodies were what against the Rh systerm(72.39%), followed by MN system (25.71%).     

Supportive care including growth factors in myelodysplastic syndromes

In spite of recent advances in the treatment of myelodysplastic syndromes (MDS), supportive care remains a very important part of the therapy. Red blood cells transfusions are the most important component of this supportive care. They transiently relieve anemia symptoms and alleviate their effects on quality of life and daily functioning. Platelet transfusion therapy is less frequently needed, at least in low-risk MDS. Dealing with an increased risk of infections linked to neutropenia, mainly by broad spectrum antibiotics, is also needed, more often in advanced stages of [dict: MDS] or when the MDS evolves to acute myeloid leukemia. Chronic red blood cell transfusions expose patients to various side-effects, including blood components intolerance reactions and alloimmunization risks, but also increased frequency of iron overload, a more significant problem in low-risk heavily transfused MDS patients, who have prolonged life expectancy. The use of growth factors is becoming a more and more important part of current supportive care. High-dose erythropoietin is able to reduce or suppress red blood cell transfusions needs in selected subgroups of MDS. The short-term use of granulocyte colony-stimulating factor is also often proposed in infections, although not formally established by prospective trials. Although trials of growth factors with thrombopoeitic activity have been performed with interleukin 11 and are underway with thrombopoeitin, none of them are available for routine use.     

Human RBC alloimmunization evaluation after exposure to foreign E antigen of the rhesus system in transfusion

Anti-E alloantibody has been one of the most frequently detected clinically significant alloantibodies in previous studies. Red blood cell (RBC) transfusion is unique in its common intravenous introduction of foreign E antigen and provides a valuable opportunity to study the human immunologic response to intravenous foreign E antigen. Patients exposed to foreign E antigen while receiving RBC transfusions are at risk of forming anti-E alloantibody. Valid estimates of anti-E alloimmunization risk are clinically important, but the forming mechanism of anti-E alloimmunization remains unclear. Here, we screened 516 inpatients at risk of exposure to foreign E antigen while receiving RBC transfusions and monitored the development of anti-E alloantibody for up to two years after left hospital. However, only 2 cases of anti-E alloimmunization were identified in this study. Patients who received RBC transfusion had a very high risk of exposure to foreign E antigen, but the anti-E alloantibody production incidence was very low and few anti-E alloantibodies were produced within 3 to 6 months after RBC transfusion in this study. Further research would contribute to our knowledge of the anti-E alloimmunization mechanism and prevent anti-E development, which would be significantly useful in clinical for transfusions, obstetric management, and the evaluation and management of transfusion reactions in laboratory and institutional resources and cost reduction in healthcare system.     

Intrauterine transfusion with red cells and platelets.

Having direct access to the fetoplacental circulation by ultrasound-directed needle puncture has led to therapeutic interventions for fetal anemia and thrombocytopenia. Most cases of red cell alloimmunization associated with fetal anemia are caused by the antibody to the D red cell antigen. The intravascular transfusion of red cells to a hydropic fetus in such cases has notably improved survival. Nonimmune hydrops fetalis due to maternal parvovirus infection has also been treated successfully with the intravascular transfusion of red cells, whereas fetomaternal hemorrhage has not proved amenable to such therapy. Sensitization to the PLA-1 platelet antigen is the most common cause of fetal thrombocytopenia in maternal platelet alloimmunization. Fetal platelet transfusions have not proved to be a practical therapeutic modality for this disorder owing to the short half-life of the platelets. Platelets transfusions to the fetus just before delivery may avert the need for cesarean section in cases of severe thrombocytopenia.     

Management and cause analysis of platelet transfusion refractoriness

Platelet transfusion refractoriness (PTR) can be defined as the less increment of platelet count than expected after platelets transfusion, which is a challenging and expensive problem often observed in platelet-transfusion-dependent patients. Although PTR occurs most frequently due to non-immune causes, a significant minority is still caused by immune factors. The most important factor in immune dependent PTR is alloimmunization against Class I human leukocyte antigens (HLAs) or human platelet antigens (HPAs). The compatible platelets can be provided to immune-mediated patients using platelet crossmatching, HLA matching, and antibody specificity testing. These measures-aimed to eliminate donor-specific HLA antibodies will lead to the improved clinical management of PTR patients, caused by severe alloimmunization.     

Redox-dependent impairment of vascular function in sickle cell disease

The vascular pathophysiology of sickle cell disease (SCD) is influenced by many factors, including adhesiveness of red and white blood cells to endothelium, increased coagulation, and homeostatic perturbation. The vascular endothelium is central to disease pathogenesis because it displays adhesion molecules for blood cells, balances procoagulant and anticoagulant properties of the vessel wall, and regulates vascular homeostasis by synthesizing vasoconstricting and vasodilating substances. The occurrence of intermittent vascular occlusion in SCD leads to reperfusion injury associated with granulocyte accumulation and enhanced production of reactive oxygen species. The participation of nitric oxide (NO) in oxidative reactions causes a reduction in NO bioavailability and contributes to vascular dysfunction in SCD. Therapeutic strategies designed to counteract endothelial, inflammatory, and oxidative abnormalities may reduce the frequency of hospitalization and blood transfusion, the incidence of pain, and the occurrence of acute chest syndrome and pulmonary hypertension in patients with SCD.     

Blood salvage, proper choice for tumor patients?

Blood transfusion is frequently used in tumor patients, However, allogeneic blood transfusion have been claimed to be associated with an increased risk of negative outcomes, including transfusion reactions, fever, virus transmission, and alloimmunization. Other risks of homologous transfusion specific to the tumor patients are the potential deleterious effects on the recurrence of tumor and indefinite overall survival. On the contrary, autologous blood transfusion offers survival advantages to tumor patients and has been shown to minimize the occurrence of many detrimental allogeneic blood associated effects and complications. It also reduces the volume of banked blood needed and improves the prognosis of patients. However, the quality of salvaged blood is still a matter of debate, because it may contain tumor cells which are associated with potential detrimental effects such as metastasis. So, an advanced technology is needed to remove such contaminants to make autologous blood transfusion safer.     

Red blood cell transfusion in patients with ST-elevation myocardial infarction—a meta-analysis of more than 21,000 patients

Background

Red blood cell transfusion remains controversial in patients with acute coronary syndromes and particularly in patients with ST-elevation myocardial infarction (STEMI).

Methods

We systematically searched PubMed, Cochrane, EMBASE, and Web of Science for studies published until January 2017 describing the outcomes in patients with STEMI who received red blood cell transfusion, compared with patients who did not.

Results

A total of 21,770 patients with STEMI from 5 cohort studies were included in the meta-analysis, 984 (4.5%) received red blood cell transfusion and 20,786 (95.4%) did not. Red blood cell transfusion was associated with a higher risk of in-hospital and long-term mortality, emergency repeated percutaneous coronary intervention (PCI), reinfarction rate, stroke rate, and heart failure. The group with red blood cell transfusion had a slightly higher incidence of diabetes mellitus and hypertension, but a lower incidence of smoking. The two groups had the same incidence of prior myocardial infarction, prior coronary artery bypass graft surgery and malignancy. Prior heart failure, prior stroke and prior PCI were more frequent in the group that had received red blood cell transfusion. The mean nadir haemoglobin was 8.5?±?0.1?g/dl in the group with red blood cell transfusion and 12.5?±?0.4?g/dl in the control group, p?<?0.001.

Conclusions

Red blood cell transfusion increases the morbidity and mortality in patients with STEMI. This difference could not be explained by the higher morbidity in the red blood cell transfusion group alone. Further randomised controlled trials are required to provide a reliable haemoglobin threshold for these patients.

     

Association of HLA-DRB1 and DQB1 alleles with red blood cell alloimmunization in Chinese

Few systematic investigations have assessed the correlations between red blood cell (RBC) antibodies and human leukocyte antigen (HLA)-DRB1 alleles in the Chinese population. In this case-control study, we investigated whether specific HLA-DRB1 alleles were associated with RBC alloimmunization by calculating the odds ratios for the frequencies of HLA alleles associated with alloimmunization to different RBC antigens. Three hundred and eight patients harboring RBC alloantibodies were analyzed as the case group, and the frequencies of the HLA-DRB1and HLA-DQB1 alleles in control individuals were analyzed by collecting data from the China Marrow Donor Program (including more than 1.6 million healthy people). HLA alleles were genotyped by single specific primer-polymerase chain reaction. The development of anti-C was associated with DRB1*07, DQB1*06, and DQB1*08; anti-C,e was associated with DRB1*07 and DQB1*06; and anti-E and anti-M were associated with DQB1. Other associations were identified between anti-E and DRB1*09 and between anti-Le^a and DRB1*01. Thus, our findings confirmed that HLA-DRB1 and DQB1 restriction played an important role in the generation of RBC alloantibodies in Chinese individuals.     

Leukocyte-depleted blood: a comparison of available preparations.

Febrile nonhemolytic transfusion reactions due to leukoagglutinins are frequently seen in patients who have been given multiple blood transfusions. To prevent or reduce the severity of these reactions, leukocyte-poor blood (that containing fewer than 0.3 X 10(9) leukocytes per unit) is frequently requested by clinicians. Four methods commonly used in Canada to produce leukocyte-poor blood were examined for their relative effectiveness and appropriate use. The mean total leukocyte count per unit was reduced to 0.22 X 10(9) in buffy-coat-poor red blood cell preparations produced by centrifugation with the blood bag inverted, to 0.19 X 10(9) by perfusion through an Imugard filter, to 0.21 X 10(9) by the use of an IBM 2991 automated cell washer and to 0.13 X 10(9) with the use of frozen blood. The proportion of red cells recovered varied from 62% with the inverted-spin method to 85% with the use of frozen blood. Comparison of these data and the percentage of leukocytes removed, the shelf life of the product, the cost of supplies and the preparation time indicated that the use of sophisticated machinery, such as the IBM cell washer, or of glycerolization plus washing of frozen cells is not warranted for most patients. Instead, patients who have febrile nonhemolytic transfusion reactions should initially be treated with a leukocyte-poor red cell preparation produced by the inverted-spin method; only if such reactions recur should the blood bank be requested to provide filtered, washed or frozen red cells.     

Anti-leuko-platelet allo-immunization in blood replacements. Do transfusions of platelets from single donors present an advantage over platelets from multiple donors?

42 patients with acute leukaemia, treated with cytotoxic drugs, have been evaluated retrospectively: --group I: 11 patients received packed red blood cells and platelets from single donors; --group II: 6 patients received packed red blood cells and platelets from multiple donors; --group III: 25 patients received packed red blood cells and platelets from single or multiple donors and granulocytes transfusions. There was no difference in age, sex, time of follow up, number of transfusions, in the three groups. The rate of alloimmunization defined as lymphocytotoxicity against more than 20% of a panel of 24 lymphocytes, was 33% (36% group I--33% group II--32% group III). This study shows that platelets from single donors are of no use in preventing or delaying alloimmunization. On the other hand, their major interest is to provide alloimmunized patients with compatible platelets.     

Effect of Human Serum Albumin Upon the Permeabilizing Activity of Sticholysin II, a Pore Forming Toxin from Stichodactyla heliantus

Sticholysin II (St II) is a haemolytic toxin isolated from the sea anemone Stichodactyla helianthus. The high haemolytic activity of this toxin is strongly dependent on the red cell status and the macromolecule conformation. In the present communication we evaluate the effect of human serum albumin on St II haemolytic activity and its capacity to form pores in the bilayer of synthetic liposomes. St II retains its pore forming capacity in the presence of large concentrations (up to 500 μM) of human serum albumin. This effect is observed both in its capacity to produce red blood cells haemolysis and to generate functional pores in liposomes. In particular, the capacity of the toxin to lyse red blood cells increases in the presence of human serum albumin (HSA). Regarding the rate of the pore forming process, it is moderately decreased in liposomes and in red blood cells, in spite of an almost total coverage of the interface by albumin. All the data obtained in red cells and model membranes show that St II remains lytically active even in the presence of high HSA concentrations. This stubbornness can explain why the toxin is able to exert its haemolytic activity on membranes immersed in complex plasma matrixes such as those present in living organisms.     

Racial and other characteristics of human T cell leukemia/lymphoma (HTLV-I) and AIDS (HTLV-III) in Trinidad.

Adult T cell leukaemia/lymphoma was first recognised as a clinical entity in southwest Japan. Subsequently the Caribbean has been found to be another area where the disease is endemic, and sporadic cases have been identified in different parts of the world. The human T cell leukaemia/lymphoma virus (HTLV-I) is causally related to adult T cell leukaemia/lymphoma. A subgroup of HTLV, designated HTLV-III, has recently been isolated from many patients with the acquired immunodeficiency syndrome (AIDS) and preAIDS, and there is now evidence that this variant is the primary cause of AIDS. This is the first report from Trinidad to describe 12 cases of adult T cell leukaemia/lymphoma and 14 of AIDS. All were in patients of African descent. No cases were seen in subjects of East Indian descent, who, like those of African descent, comprise as much as 40% of the population. West Indians of African descent may have increased susceptibility to infection with both HTLV-I and HTLV-III.     

甲氧基聚乙二醇(mPEG)修饰遮蔽人ABO血型抗原

输血是一种非常有效的临床治疗手段 ,但血型不符会造成输血死亡事故 .为了解决输血中存在的血型匹配困难等问题 ,使用甲氧基聚乙二醇 (mPEG)化学修饰法 ,对红细胞表面的血型抗原进行化学修饰 ,从而达到遮蔽红细胞血型抗原的目的 .通过对mPEG BTC、mPEG ALD和mPEG 2 NHS三种mPEG衍生物对红细胞A抗原和B抗原修饰效果的比较 ,结果表明mPEG BTC修饰效果最好 ,可以完全遮蔽红细胞的A抗原和B抗原 ,使修饰后的A型、B型和AB型红细胞呈现出与O型红细胞相同的血型血清学特征 ;进一步研究证明 ,mPEG BTC与红细胞结合牢固 ,对红细胞结构、功能、变形能力、常规指标和沉降率等基本没有影响 .初步实现了A→O ,B→O和AB→O的血型改造 ,从而为临床输血治疗遇到的偏型、稀有血型、配型困难等问题的解决 ,提供了新的技术方法与思路 .     

Sickle cell disease and malaria morbidity: a tale with two tails

More than 230,000 children are born in Africa with sickle cell disease (SCD) each year: approximately 85% of all affected births worldwide. Although malaria is commonly viewed as a major problem for African patients with this condition, questions still remain about its relative importance as a cause of ill heath and death. In the absence of definitive studies investigating the contribution of malaria to morbidity and mortality in African children with SCD, policy makers will continue to lack the evidence on which to base appropriate management guidelines.     

Influence of the amount of antigen and the interval on the secondary reaction

The course of the revaccination reaction in mice immunized with different doses of sheep red blood cells was determined at different intervals after the primary stimulus. The maximum level of haemagglutinating antibodies in the secondary reaction was found after a high primary and secondary antigenic stimulus. On the contrary, if the level of haemolytic antibodies was determined, the higher was the primary antigenic stimulus, the lower was the secondary antibody response. Differences between haemagglutinins and haemolytic antibodies were also manifested in the earlier onset of the maximum haemolytic secondary reaction (five months after the first dose of antigen); the maximum haemagglutination response was not attained until eight months after the primary dose of antigen. The results comfirm that the basis of preparation for the secondary reaction is proliferation of immunologically activated Y cells; differences in the haemolytic and haemagglutination response are related to differences in the character of the antigenic determinants of sheep red cells.     

Prevalence and specificity of some rare red cell pan-reactive alloantibodies against high frequency red cell antigens among hospitalized Saudi patients

Some patients'' sera react with all available donors'' red cells and a compatible donor is difficult or impossible to be found. These may either be due to a complex mixture of antibodies or the presence of alloantibodies against high-frequency antigens (HFAs). The aim of this study is to identify the prevalence and characteristics of antibodies to HFAs in Saudi Arabian patients. A total of 23 out of 172 000 patients who received blood transfusions had rare alloantibodies to HFAs at an incidence of 0.013%. Twenty-three patients suspected with pan-reactive alloantibodies against HFAs had their red cells tested using antisera to HFAs, while their plasma was tested against a selected panel of red blood cells with rare phenotypes. Anti-Ge2 antibody was found in the highest number of patients (56.5%), whereas anti-U, anti JK3, anti H, anti-RH 29, anti-hr^s, anti-Kn^a, anti-Ch, anti-Rg, anti-Yt^a, and anti-Cr^a antibodies were found in the remaining patients (43.5%). This study suggests that although antibodies such as anti-Ge2, anti- Kn^a, anti-Ch, anti-Rg, anti-Yt^a , and anti-Cr^a are not clinically significant, they cause a delay in the provision of compatible blood. Whereas, anti-U, anti JK3, anti H, anti-RH29 and anti-hr^s are clinically significant antibodies. An understanding of antibody characteristics to HFAs and the widespread use of the extended red cell phenotype and antibody identification panel will both be helpful for the diagnosis of these HFAs.     

The molecular genetics of blood group polymorphism

Over 300 blood group specificities on red cells have been identified, many of which are polymorphic. The molecular mechanisms responsible for these polymorphisms are diverse, though many simply represent single nucleotide polymorphisms (SNPs). Other mechanisms include the following: gene deletion; single nucleotide deletion and sequence duplication, which introduce reading-frame shifts; nonsense mutation; intergenic recombination between closely linked genes, giving rise to hybrid genes and hybrid proteins; and a SNP in the promoter region of a blood group gene. Examples of these various genetic mechanisms are taken from the ABO, Rh, Kell, and Duffy blood group systems. Null phenotypes, in which no antigens of a blood group system are expressed, are not generally polymorphic, but provide good examples of the effect of inactivating mutations on blood group expression. As natural human ‘knock-outs’, null phenotypes provide useful clues to the functions of blood group antigens. Knowledge of the molecular backgrounds of blood group polymorphisms provides a means to predict blood group phenotypes from genomic DNA. This has two main applications in transfusion medicine: determination of foetal blood groups to assess whether the foetus is at risk from haemolytic disease and ascertainment of blood group phenotypes in multiply transfused, transfusion-dependent patients, where serological tests are precluded by the presence of donor red cells. Other applications are being developed for the future.     

The prevalence of alloantibody in the population of Xinjiang area of China

Alloantibodies are the major cause of hemolytic transfusion reaction and newborn hemolytic disease. It is highly recommended to screen alloantibodies before transfusion and pregnancy. This report applied the microcolum gel method to screen for available alloantibodies, enrolling 20,098 patients from January 2016 to December 2017 in the Xinjiang General Hospital. Seventy-two patients were found alloantibody-positive, at an overall positive rate of 0.35%. The distribution of alloantibody varied according to age, gender or treatment. The patients aged 70 plus and the patients admitted in the Department of Hematology and Department of Gynecology & Obstetrics had a higher incidence rate of alloantibodies. By using 10 screening cell panel systems, 9 types of alloantibodies including anti-D, anti-E, anti-e, anti-C, anti-c, anti-M, anti-s, anti-Fy^b and anti-Ce were identified. This study suggests that the transfusion of red blood cells(RBCs) and pregnancy are the main causes of alloantibodies.     

Prevalence of Vitamin D Deficiency in Sickle Cell Disease: A Systematic Review

Vitamin D deficiency has emerged as a public health focus in recent years and patients with sickle cell disease (SCD) reportedly have a high prevalence of the condition. Our objectives were to summarize definitions of vitamin D deficiency and insufficiency used in the literature, and to determine the prevalence and magnitude of each in patients with SCD through a systematic review conducted according to PRISMA guidelines. From a PubMed search, 34 potential articles were identified and 15 met eligibility criteria for inclusion. Definitions of deficiency and insufficiency varied greatly across studies making direct comparisons difficult. This review provides evidence to suggest that suboptimal vitamin D levels are highly prevalent among those with SCD, far more so than in comparable non-SCD patients or matched control populations. Defining deficiency as vitamin D <20ng/mL, prevalence estimates in SCD populations range from 56.4% to 96.4%. When compared with results from the population-based National Health and Nutrition Examination Survey, however, the general African American population appeared to have a similarly high prevalence of vitamin D deficiency. African American patients with and without SCD were both substantially higher than that of Caucasians. What remains to be determined is whether there are adverse health effects for patients with SCD because of concurrent vitamin D deficiency.