Prevalence and specificity of red-blood-cell antibodies in a multiethnic South and East Asian patient population and influence of using novel MUT+Mur+ kodecytes on its detection

Background and Objectives Appropriate screening for irregular red‐cell antibodies is essential for ensuring transfusion compatibility and for antenatal management of mothers at risk of haemolytic disease of the foetus and newborn. Screening for all relevant antibodies is, however, limited by screening cells that do not express antigens present in the patient and donor population. Technology to artificially incorporate antigens into red cells is currently available and may be an option for customizing screening cells. Materials and Methods We sought to identify retrospectively the changing patterns of alloantibody prevalence in our multiethnic population on change of screening cells. Antibody screening records of 143 501 patients tested from 2004 to 2010 were retrieved and divided into two groups: period‐1 (2004–2008) and period‐2 (2009–2010). During period‐1, standard screening cells were used while in period‐2, MUT+Mur+ KODE^? transformed red cells (kodecytes) were used. Results Four per cent of samples tested during period‐2 were positive on antibody screening compared to 3·2% in period‐1. Specific antibodies, excluding anti‐D, were identified in 1·66% and 1·52% of patients in period‐2 and ‐1, respectively. When confined to antibodies of clinical significance only, period‐2 showed higher alloantibody prevalence of 1·16% as compared to 0·66% in period‐1. Antibodies to glycophorin variants of MNS (vMNS) were more commonly detected while antibodies to Lewis antigens declined during period‐2. Conclusion Antibodies to vMNS antigens are common in South and East Asian populations and are often missed when using standard screening cells. Use of specifically engineered screening cells to express red‐cell antigens artificially is beneficial in detecting the diverse alloantibodies present in our population.     

Preoperative anemia and extensive transfusion during stay-in-hospital are critical for patient`s mortality: A retrospective multicenter cohort study of oncological patients undergoing radical cystectomy

Background

Preoperative anemia and allogeneic blood transfusions (ABTs) may affect outcomes in cancer surgery. The prevalence of anemia, the use of ABTs, the risks of transfusions, lengths of stay and mortality of oncological patients undergoing radical cystectomy were investigated in three University Hospitals in Germany.

Neonatal RBC transfusions: Do benefits outweigh risks?

Preterm neonates represent one of the most transfused categories of patients. Their target hematocrits, however, are mainly based on expert opinion. The risk of transfusions are very high in the smallest preterm baby with a weak immune response, immature antioxidant ability, fragile germinal matrix and impaired cerebral autoregulation, yet red cell transfusions remain the only life saving measure in the baby with symptomatic anemia.Minimizing phlebotomy losses, following a restrictive transfusion policy and using screened, leukocyte depleted, irradiated, single donor blood remain the best means of avoiding the possible risks while maximizing the benefits of red cell transfusions in the preterm newborn.     

Protective effect of flavonoids against red blood cell hemolysis by free radicals

BACKGROUND:

Flavonoids are polyphenolic substances with antioxidant properties, and they are found in different vegetables and fruits. Epidemiological studies have shown that the consumption of flavonoids reduces the prevalence of cardiovascular diseases. The use of synthetic antioxidants, however, has been limited because of their toxicity. Therefore, medical researchers have intensified their quest to find natural antioxidants.

OBJECTIVES:

To investigate the effect of several pure flavonoids, such as kaempferol, quercetin, morin and rutin, on red blood cell hemolysis and evaluate their -SH capacity as an indicator of membrane protection.

METHODS:

The rate of hemolysis and cell membrane -SH capacity were determined by spectrophotometry. Red blood cell peroxidation was induced using 2,2′-azo-bis-(2-amidinopropane) dihydrochloride. The effect of each flavonoid on hemolysis was examined at three concentrations (0.5 μg/mL, 5 μg/mL and 10 μg/mL), however, only the greatest concentration (10 μg/mL) of each flavonoid was used to study the effect on -SH groups.

RESULTS:

In all cases, the antioxidant activity was dose-dependent. Rutin showed the highest inhibitory effect on hemolysis among flavonoids (42.5%). The protective effect of kaempferol, rutin and morin against -SH group oxidation measured 7.7%, 23.3% and 26.4%, respectively.

CONCLUSIONS:

Results showed that flavonoids and flavonoid-containing plants can be used as natural antioxidants for the treatment and prevention of disease conditions, the pathogenesis of which is mediated by lipid peroxidation.     

Prevalence,specificity and risk of red blood cell alloantibodies among hospitalised Hubei Han Chinese patients

Background

The prevalence, specificity and risk of red blood cell alloantibodies vary widely among different geographic areas, races, and diseases and according to different methods of study, but no data are available on the Chinese Han population, who were investigated in the present study.

Materials and methods

Antibody screening was conducted among 42,517 hospitalised Hubei Han Chinese individuals using column agglutination technology. Samples that were positive in antibody screening were subjected to antibody identification by the tube test. Clinical data, including gender, age, race, transfusion history and records of alloantibody detection, transfusion reactions or haemolytic disease of the newborn, were collected to analyse the prevalence and specificity of alloantibodies and complications associated with them.

Results

A total of 212 patients with alloantibodies were identified among 42,517 patients, yielding a prevalence of 0.50% in this study. Significantly different prevalence rates were observed according to age and sex. The most frequently identified alloantibodies were anti-E (87/212, 41.0%), anti-D (45/212, 21.2%), anti-M (41/212, 19.3%) and a combination of anti-E and anti-c (13/212, 6.1%). Haemolytic disease was observed in 13 infants with anti-D, three infants with anti-E and one infant with anti-Fy^a alloantibodies. Delayed haemolytic transfusion reactions occurred in four patients with alloantibodies.

Discussion

In hospitalised Hubei Han Chinese individuals, the overall prevalence of alloantibodies was 0.50%, with anti-E, anti-D and anti-M being the most frequently identified alloantibodies. These results indicate that anti-D and anti-E alloantibodies were major risk factors for haemolytic disease of the newborn or delayed haemolytic transfusion reactions in this study population.     

Measurement of Individual Red Blood Cell Motions Under High Hematocrit Conditions Using a Confocal Micro-PTV System

Developments in optical experimental techniques have helped in elucidating how blood flows through microvessels. Although initial developments were encouraging, studies on the flow properties of blood in microcirculation have been limited by several technical factors, such as poor spatial resolution and difficulty obtaining quantitative detailed measurements at such small scales. Recent advances in computing, microscopy, and digital image processing techniques have made it possible to combine a particle tracking velocimetry (PTV) system with a confocal microscope. We document the development of a confocal micro-PTV measurement system for capturing the dynamic flow behavior of red blood cells (RBCs) in concentrated suspensions. Measurements were performed at several depths through 100-μm glass capillaries. The confocal micro-PTV system was able to detect both translational and rotational motions of individual RBCs flowing in concentrated suspensions. Our results provide evidence that RBCs in dilute suspensions (3% hematocrit) tended to follow approximately linear trajectories, whereas RBCs in concentrated suspensions (20% hematocrit) exhibited transversal displacements of about 2% from the original path. Direct and quantitative measurements indicated that the plasma layer appeared to enhance the fluctuations in RBC trajectories owing to decreased obstruction in transversal movements caused by other RBCs. Using optical sectioning and subsequent image contrast and resolution enhancement, the system provides previously unobtainable information on the motion of RBCs, including the trajectories of two or more RBCs interacting in the same focal plane and RBC dispersion coefficients in different focal planes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

陈旧血电泳出现快泳红带的原因分析—红细胞释放“高铁血红素”?

[目的]用陈旧血做血红蛋白释放试验时,有些标本出现快泳的红色区带,其他标本没有这种现象。本文的目的就是研究快泳红带的来源、本质和意义。[方法]用淀粉-琼脂糖混合凝胶电泳,对有快泳红带的标本作进一步分析:血浆蛋白电泳、血红蛋白电泳、红细胞电泳以及全血电泳,分析快泳红带之来源。再用交叉电泳和双向电泳研究它的本质。[结果]此快泳红带的电泳速度与血浆白蛋白相近,丽春红染色阳性、联苯胺显色也是阳性。红带中的联苯胺阳性成分来自红细胞,与血浆白蛋白结合形成快泳红带。[结论]来自红细胞的成分很可能是高铁血红素,快泳红带可能是它与血浆白蛋白的结合产物-高铁血红素白蛋白(MHA)。     

溶血指数在测定葡萄糖-6-磷酸脱氢酶活性中的应用

目的应用血清信息中的溶血指数计算出每克血红蛋白的葡萄糖-6-磷酸脱氢酶(G6PD)的活性。方法在生化仪上测定压积红细胞G6PD的活性,结合溶血指数的测定以及其和血红蛋白含量的显著相关关系,计算出G6PD的活性浓度,即每克血红蛋白的G6PD活性,并将G6PD缺乏阳性率和G6PD/6磷酸葡萄糖脱氢酶(6PGD)比值法进行比较。结果利用溶血指数计算每克血红蛋白中G6PD活性浓度法在G6PD缺乏的检出率与G6PD/6PGD比值法差异无统计学意义,两种方法检出能力一致。结论利用溶血指数计算G6PD的活性浓度操作简单方便,无需洗涤压积红细胞,且无需测定6PGD和血红蛋白,在G6PD缺乏的筛查中有一定的意义。     

妊高征患者外周血红细胞免疫功能的变化和血浆TXB2水平的相关性分析

目的:探讨妊高征患者外周血红细胞免疫功能的变化和血浆TXB2水平的相关性.方法:应用放射免疫分析和免疫法对33例妊高征患者进行红细胞免疫功能和血浆TXB2检测,并与35名正常人作比较.结果:妊高征患者RBC-C3bRR水平明显降低(P<0.01),而血浆TXB2水平显著升高(P<0.01),RBC-C3bRR与TXB2...