The progress in pre-transfusion test technique research

Pre-transfusion tests include ABO/RhD blood typing, irregular antibody screening and cross-matching test, which are pivotal for safe and effective clinical transfusion. The best pre-transfusion test technology should be selected to ensure the safety of the clinical transfusion, use blood resources effectively, improve the transfusion’s effect, and achieve a precision transfusion. Here we reviewed the progress of main techniques and applications of pre-transfusion tests in recent years. aiming to give clinicians a systematic understanding of current pre-transfusion test techniques in clinical transfusion treatment.     

Purification and characterization of a recombinant alpha-N-acetylgalactosaminidase from Clostridium perfringens

Clostridium perfringens alpha-N-acetylgalactosaminidase (alphaNAG) hydrolyzed the terminal N-acetyl-alpha-d-galactosamine from the blood type A(2) antigen producing H antigen, blood type O. Blood type O is universally compatible in the ABO system. Purification of the native enzyme is difficult with very low yields. To obtain the enzyme in satisfactory yield, the gene encoding the clostridial enzyme was cloned in an Escherichia coli T7 expression system. A highly purified preparation of recombinant alphaNAG was obtained from cell lysates by ion-exchange chromatography and high-pressure liquid chromatography. The final preparation was homogeneous by SDS-PAGE with a molecular mass of 71.96kDa and the native molecular weight of 72.42kDa. The enzyme was highly selective for terminal N-acetylgalactosamine residues. No other significant exoglycosidase activities, particularly neuraminidase, were detected. The pH optimum of the enzyme was between 6.5 and 7.0 and activity was relatively unaffected by ionic strength. ELISA experiments demonstrated activity against blood type A(2) epitope. These characteristics were similar to those of native alphaNAG from C. perfringens. With adequate expression in E. coli, sufficient recombinant alphaNAG enzyme mass can be obtained for potential use in enzymatic conversion of human blood type A(2) red blood cells to universally transfusable type O red blood cells.     

Molecular characterization of ABO blood group frequencies in pre-Columbian Peruvian highlanders

The majority of Native Americans nearly exclusively belong to group O of the ABO blood group system. Several hypotheses have been formulated to explain this observation, primarily differing by the presumption that the observed patterns of ABO diversity are due to the processes of the initial peopling of the Americas or due to subsequent events, especially the demographic consequences in the wake of European contact. A promising strategy to reveal possible diachronic ABO frequency changes is the molecular genetic analysis of relevant genetic markers in precontact populations. A previous study by Halverson and Bolnick [Am J Phys Anthropol 137 (2008) 342‐347] already accomplished this for indigenous North American populations. Here we present the first study to analyze ABO blood types from pre‐Columbian individuals from South America using molecular genetic methods and comparing them to several extant South American, North American, and Siberian populations. We tried to determine ABO blood types for 59 individuals from the southern Peruvian highlands dating to ～650 to 1250 AD using a newly developed multiplex PCR/SBE assay coamplifying the fragments relevant for blood type determination and three highly discriminating autosomal STRs. Analysis was successful for 31 individuals and revealed that all are exclusively in the O group, predominantly carrying the O02 (01v) allele. No significant difference could be observed between the ancient and modern Native American populations, while all significantly differed from the extant Siberian populations, supporting the suggestion that low ABO diversity results from founder effects during the initial peopling of the Americas. Am J Phys Anthropol 149:242–249, 2012. © 2012 Wiley Periodicals, Inc.     

Molecular genetic analysis of weak B blood group allele in Jinan population reveals distribution of ABw phenotype

The aim of this study was to investigate the distribution of the ABw phenotype of ABO blood group in the Jinan population. 31 856 samples were tested during the period 2018 to 2019. Thirty-nine samples with discrepant results, as identified by micro-column gel method, were further investigated by serological (tube technique) and molecular (fluorescence PCR, DNA sequencing) methods. Eight samples showed ABw phenotype, which accounted for 0.025% of the population tested. From the sequencing analysis, six samples (6/8) were typed as ABO*A1.02/ABO*BW.12 and two samples (2/8) as ABO*A1.02/ABO*BW.03. The study suggests that ABw12 account for 75% of ABw phenotype and indicate ABw12 is the main ABw phenotype in Jinan population.     

Cardiac allotransplantation across major blood group barriers in the baboon

In heterotopic heart transplantation experiments in Chacma baboons, some of the animals were significantly immunosuppressed with cyclosporine, resulting in prolonged cardiac allograft survival. ABO blood group incompatibility between recipient and donor did not significantly influence mean allograft survival, but early hyperacute (vascular) or acute (cellular) rejection occurred only when ABO incompatibility was present.     

ABO血型正反定型及交叉配血实验在外科病人手术输血中应用

目的:探讨ABO血型正反定型及交叉配血实验在外科手术患者输血中的应用效果及影响因素。方法:选取我院自2017年2月-2019年2月收治的80例行ABO正反定型与交叉配血治疗的外科手术患者,记录ABO反定型与交叉配血不合的标本,使用2-Me处理被患者自身冷抗体凝集的红细胞,同时使用微柱凝胶法、凝聚胺法对血型不规则抗体以及特异性进行筛选和鉴定。分析ABO血型反定型不符合以及交叉配血不合的影响因素。结果:对正反定型完全无凝集反应的80例血清标本进行交叉配血实验,其中8例存在凝集反应,配血不合情况;导致外科手术患者输血中ABO血型反定型不符交叉配血不合的主要因素包括自身冷抗体、血型抗原性减弱、血型不规则抗体以及血型抗体效价减弱等。结论:ABO血型正反定型及交叉配血治疗中的患者中,大部分配血一致,少数的交叉配血不合,主要与自身冷抗体、血型抗原性减弱、血型不规则抗体以及血型抗体效价减弱等因素相关。     

ABH Salivary antigens in populations of vervet monkeys(Cercopithecus aithiops) from Kenya

Blood and saliva samples were collected from 330 vervet monkeys living in 30 troops in central and southern Kenya. The saliva samples were tested for the presence of human-type ABH antigens by standard agglutinationinhibition tests. This population of vervets is the first in which the O phenotype has been found to occur. The gene frequencies in the overall population are as follows: A, 0.74; B, 0.21; and O, 0.05. The serum samples were tested for the presence of agglutinins having specificities like those of human anti-A and anti-B. Ten percent of the vervets have anomalous combinations of salivary antigens and serum agglutinins. The nature of the anomalies is described and a hypothesis presented to account for these observations.     

Association between ABO blood types and pain perception

Aim of the study: Pain perception is associated with different phenotypic characteristics such as sex, eye, and hair color. Hence, it is assumed that ABO blood type can also affect pain perception.

Materials and methods: In order to investigate this hypothesis, an experimental study with healthy volunteers (18–40?years) was designed. The experimental procedure included a blood type test and two rounds of pressure pain threshold assessments separated by a cold pressor test. Pressure pain threshold was assessed bilaterally at the temporalis, masseter, and deltoid muscles, where the muscle sites were randomized. Cold pressor test was conducted by immersion of participants’ non-dominant hand into iced water of 1–4?°C for 2?min.

Results: Thirty-seven healthy volunteers, distributed in the four blood type groups, completed the study. Participants with blood type B scored the highest pressure pain thresholds at the examined craniofacial muscles, while participants with blood type AB tended to score the lowest. Furthermore, participants with blood type AB displayed the highest elevation in pressure pain thresholds after cold pressor test.

Conclusions: Participants with blood type B displayed the lowest mechanical pain sensitivity and the blood type AB group exhibited the strongest conditioned pain modulation effect. These findings emphasize the necessity of considering ABO blood types in future pain research.