不规则抗体导致ABO正反定型不符处理探讨

目的探讨不规则抗体导致ABO正反定型不符原因,并提出解决方法。方法总结分析12例不规则抗体导致ABO正反定型不符血型血清学试验结果,通过不规则抗体筛查、不规则抗体鉴定、相应血型检测明确不规则抗体导致ABO正反定型不符确切原因,用相应抗原阴性红细胞重新进行ABO血型反定型。结果 12例标本中抗-M 4例,抗-N 1例,抗-M合并抗-N 1例,抗-Lea1例,抗-P11例,抗-I 1例,抗-D 1例,抗-E 1例,抗-A11例。用相应抗原阴性红细胞重新进行ABO血型反定型,正反定型结果均相符。结论不规则抗体是导致ABO正反定型不符的常见原因,经过适当处理可以正确鉴定ABO血型。     

PCR-SSP基因分型技术在ABO疑难血型定型中的应用

目的 研究聚合酶链式反应-特异性序列引物(PC-SSP)基因分型技术在ABO疑难血型鉴定中的应用.方法 收集8例来自广东省肇庆市无偿献血者的ABO疑难血型样本,采用正反定型实验、吸收放散试验等一系列血型血清学方法进行检测;提取基因组DNA,并用PCR-SSP基因分型技术,特异性扩增ABO基因片段,根据有无PCR产物以及产物长度,判断样本的基因型.结果 通过凝胶电泳检测PCR反应的特异性产物,判断样本1～6号ABO基因型为A/O型,样本7,8号为B/O型.8例疑难ABO基因分型结果与其血型的血清学分型结果吻合.结论 ABO疑难血型定型的解决是一个复杂的难题,而PCR-SSP基因分型是一种方便、快速、可靠的技术,对于解决ABO疑难血型鉴定非常有用.     

Solid-phase ABO grouping and Rh typing

A solid-phase adherence method (SPAM) for ABO grouping and Rh typing of red cells (RBCs) has been developed. Adherence reactions were read spectrophotometrically and interpreted by a computer. The SPAM had a 99.6 percent correlation with conventional microplate agglutination methods for ABO grouping and Rh typing. The increased sensitivity of the SPAM was demonstrated because it directly detected Du-positive RBCs and weak subgroups of A and B.     

Simulated ABO and Rh blood typing

BACKGROUND: Blood typing historically has been used to introduce students to the concepts of immunohematology. Risk of disease transmission has compelled school districts to prohibit the use of human blood in student laboratories. A method is needed that will safely simulate ABO and Rh typing. STUDY DESIGN AND METHODS: A method that uses inorganic salt solutions to simulate ABO and Rh antigens and antibodies was studied. Additional salt solutions and diluents were tested to investigate the feasibility of simulating both ABO and Rh typing in a more realistic medium. RESULTS: Cobalt nitrate and sodium hydroxide were found to successfully simulate D and anti-D, respectively. The addition of these solutions did not produce cross- reactions in ABO tests. Use of simulated blood as a diluent improved the appearance of the samples. CONCLUSION: This method can safely and inexpensively simulate ABO and Rh blood typing procedures and provide students with hands-on blood-typing experience.     

3种常用溶液配制ABO反定型红细胞的探讨

目的对3种常用溶液配制ABO反定型红细胞悬液进行比较。方法利用生理盐水、低离子溶液、Sysmex血液分析仪用稀释液3种溶液制备2%的红细胞悬液,(4±2)℃冰箱保存,每天对红细胞的凝集强度、红细胞数量和质量、上清液游离血红蛋白进行观察,每3天监测一次细菌生长情况等。观察用3种溶液制备的反定型红细胞的有效期限。结果用Sysmex血液分析仪专用稀释液配制的反定型红细胞有效期仅6 d,用生理盐水配制的反定型红细胞有效期不到24 h,低离子溶液配制的反定型红细胞当天溶血。结论用Sysmex血液分析仪专用稀释液可制备简便的ABO反定型红细胞,有效期6 d;低离子溶液不适用于配制的反定型红细胞;生理盐水配备的反定型红细胞应每天配制。     

献血者ABO血型正反定型不符检测结果分析

目的分析献血者ABO血型正反定型不符的情况,采用分子生物学技术准确鉴定血型,为安全输血提供保障。方法收集2016年6月至2017年6月本血站73例ABO血型正反定型不符标本,采用血型血清学方法检测ABO血型,PCR-SSP法及直接测序方法确定基因型。结果 73例正反定型不符标本中ABO血型正定型为A型,抗-B减弱标本56例,检出4种基因型分别为19例AO1、21例AO2、15例AA、1例A205O2为A2亚型;正定型为B型,抗-A减弱9例,检出2种基因型分别7例BO1、2例BO2;正定型为O型,抗-B减弱7例,检出3种基因型分别为2例BO1为B亚型、4例O1O2、1例O1O1;正定型为O型,抗-A减弱1例,检出基因型AO1为A亚型。其中,4例ABO亚型经基因测序结果分别为A205/O02、Bel03/O01、Bw17/O01、Ax01/O01。结论对于献血者正反定型不符时,应通过血清学与基因检测及DNA测序相结合的方法,正确鉴定血型,为临床提供安全的血液。     

抗A和抗B血型定型试剂稳定性观察及对亚型检测的影响

目的检测国产单克隆抗A(B)试剂质量,观察对ABO亚型检测的影响。方法测定四个厂家"单抗A、抗B"试剂效价、亲和力等,并检测稀有的ABO亚型红细胞与单克隆试剂反应情况,同时用人源抗A、抗B试剂作对照。结果所有厂商的试剂均符合国家标准,单克隆抗体仍有漏检ABO亚型现象。结论目前市场销售的单克隆抗A、抗B血型定型试剂,质量基本可靠,但应定期测定其效价、亲和力,受检者ABO血型检测必须用ABO反定型试验复核。     

Evaluation of the gel system for ABO grouping and D typing

BACKGROUND: The gel agglutination assay has been approved by the Food and Drug Administration as an alternative to the tube assay for the detection of red cell antibodies. It has also been approved recently by the Food and Drug Administration for ABO blood grouping and D typing. STUDY DESIGN AND METHODS: Tube and gel agglutination assays were compared for ABO grouping and D typing of 100 donor and 100 patient specimens. ABO grouping of 14 specimens of known ABO groups and D typing of 10 specimens with weak D were also compared. When antigen typing or isohemagglutinin results differed, gel testing was repeated by the use of modified incubation times, reagent or specimen volumes, and red cell concentrations. RESULTS: ABO grouping and D typing in all patient and donor specimens concurred. B isohemagglutinins were not detected in seven group A specimens. Six of seven discrepancies were resolved when gel tests were incubated at room temperature with increased serum or plasma volume. Weak D was detected in all 10 specimens tested by both assays. When weak A and/or B were tested with monoclonal antibody reagents, the correct phenotypes were identified in 9 specimens by gel assay and in 10 by tube assay. Using human antisera, 6 specimens were correctly phenotyped by gel assay and 7 by tube assay. CONCLUSION: The gel assay performed as well as the tube assay in detection of A, B, and D, but the tube assay was slightly better at detecting B isohemagglutinins. The gel assay can be used in place of the tube assay for ABO blood grouping and D typing.     

Nondeletional ABO*O alleles frequently cause blood donor typing problems

BACKGROUND: Difficulties in the demonstration of expected isoagglutinins is a common problem in ABO reverse typing. Some nondeletional ABO*O alleles have been shown to encode for the expression of minimal amounts of A antigen, resulting in very weak anti-A activity in some cases. It is unknown whether minor problems with ABO reverse typing are related to specific ABO*O alleles. STUDY DESIGN AND METHODS: Among 2196 blood group O red cell (RBC) donations, the ABO alleles of those donations in which the isoagglutinins were incorrectly identified were analyzed with an autoanalyzer. The presence of nondeletional ABO alleles was determined by sequence-specific priming and sequencing. RESULTS: Fifty (2.3%) of the group O RBC donations tested had to be typed manually because of isoagglutinin detection problems in automated typing: reduced anti-A activity was observed in 45 cases, reduced anti-B activity in 4 cases, and variably reduced isoagglutinin activity in 1 case. The nondeletional ABO*O alleles ABO*O03 and ABO*Aw08 were implicated in 38 of these 50 cases (1.7% of all blood group O donors). The remaining samples, including those with reduced anti-B activities, were homozygous for deletional ABO*O alleles. CONCLUSION: Nondeletional ABO*O alleles are the most frequent cause of isoagglutinin detection problems in blood group O donors.     

Discrepancies in fluorescent antibody, counterimmunoelectrophoresis, and Neufeld test for typing of Streptococcus pneumoniae

The techniques of fluorescent antibody (FA) and counterimmunoelectrophoresis (CIE) were compared with the Neufeld test (quellung reaction) for typing of Streptococcus pneumoniae. A total of 88 isolates were examined by these three methods. Pool-, type-, or group-specific pneumococcal antisera were used in all three methods. Each isolate was initially tested with polyvalent antisera and all of the nine pools of antisera. Selection of the type- or group-specific antisera depended upon the reaction of the isolate with the pool sera. Sixty-eight of 88 (77.3%) isolates were positive using pool or typing sera and were correctly typed by CIE, while FA was found to be accurate for only 61 of 88 (69.3%) isolates. Positive reactions with more than one pool- or type-specific antisera, or no reaction, were seen with several of the isolates with both techniques. Even though CIE and FA are rapid and simple techniques, microbiologists should be cautious when utilizing them for typing of S. pneumoniae because of the discrepancies observed in this study.     

A rapid ABO and RhD test demonstrates high fidelity to blood bank testing for RhD typing

Background

The rapid provision of blood products is life-saving for patients with massive hemorrhage. Ideally, RhD-negative blood products would be supplied to a woman of childbearing potential whose Rh type is unknown due to the risk of D-alloimmunization and the potential for hemolytic disease of the fetus and newborn to occur if RhD-positive blood products are transfused. Therefore, there is a need for a test that rapidly determines her RhD type. This study compared the RhD type determined using a rapid ABO and RhD test to the RhD type determined by an immunohematology reference laboratory.

Methods

After receiving ethics review board approval, 200 random, unique, deidentified patient samples that had undergone routine pretransfusion testing in an immunohematology reference laboratory using column agglutination technology were collected and tested using a rapid ABO and RhD test (Eldoncard Home kit 2511). The RhD typing results from these two methods were compared to determine the accuracy of the rapid ABO and RhD test.

Results

The rapid ABO and RhD test produced results that were concordant with the transfusion service's results in 199/200 (99.5%) of cases, with a negative predictive value of 98.2% and 99.3% sensitivity. The single outlier was likely an RhD variant due to its serological characteristics.

Discussion

These data indicate that this rapid ABO and RhD test could be used for the rapid determination of a patient's RhD type, perhaps even in the emergency department, which could guide the selection of blood products provided during their resuscitation.     

Evaluation of polyethylene terephthalate for ABO and Rh typing and alloantibody screening

BACKGROUND: For many years, hospitals and laboratories have used evacuated glass tubes for blood collection. To improve the safety of blood collection, plastic polyethylene terephthalate (PET) tubes (Vacutainer PLUS, Becton Dickinson) have been developed. The objectives of this study were to compare the accuracy of ABO grouping, Rh typing, and antibody screening of blood samples collected in plastic tubes with that in glass tubes and to determine if refrigerated blood samples collected in plastic tubes remained stable over a 28-day period. STUDY DESIGN AND METHODS: Samples were collected from 121 volunteers, at least 30 from each of the A, B, O, and AB blood groups, in four types of Vacutainer tubes: silica-coated plastic, K(2) EDTA plastic, uncoated glass, and K(2) EDTA glass. Samples from each tube were tested for ABO group and Rh type by use of the microtyping gel identification card system and the tube method. A three-cell antibody screen was performed by the microtyping gel card technique with a monospecific IgG reagent. Initial samples were tested within 3 hours of collection. Refrigerated samples were retested for ABO and Rh type and antibody screening 1, 2, 21, and 28 days later. Agreement between test results was determined by using Cohen's Kappa statistic. RESULTS: Complete agreement was observed between the ABO and Rh typing results in samples drawn into glass and plastic tubes of both the EDTA and nonanticoagulated type (kappa = 1.0). In retesting, there were no examples of a change in ABO or Rh type over the 28-day study period. Only two alloantibodies (1.7%) were identified in the 121 samples, and no difference was observed in alloantibody expression in either plastic or glass Vacutainer tubes over the 28-day study period. CONCLUSION: Samples collected into the PET serum or EDTA tubes provided accurate ABO and Rh typing results that remained consistent over a 28-day period. Samples collected in these tubes also appeared to enable accurate alloantibody identification. However, the number of alloantibodies identified in this study was small, and this result should be confirmed in a larger series.