The ABO blood group system is the most important blood group system in clinical transfusion. Serological technology is a routine method for the identification of ABO blood groups, however, which have some limitations in the identification of complicated ABO samples with weakened antigens or antibodies, abnormal plasma proteins, polyagglutination, or cold agglutinin, etc. With the development of molecular biology technology, ABO blood group gene was cloned, and ABO blood group genotyping technology based on DNA was established. The genotyping technologies with different throughputs such as PCR-SSP, Droplet-AS-PCR, PCR-RFLP, PCR-SBT, SNaPshot, MALDI-TOF MS and NGS have emerged. Genotyping has overcome the limitations of serology, and has become an indispensable method to solve difficult blood type, providing strong support for the correct identification of ABO blood group, and providing guarantee for precision blood transfusion. This review summarizes the progress and application of ABO blood group genotyping methods.
ABO Blood-Group System/genetics* ; Blood Grouping and Crossmatching ; Genotype ; Humans ; Polymerase Chain Reaction/methods* ; Technology

BACKGROUND: According to increased availability and awareness of automated blood bank analyzer with its speed and efficiency, use of automated analyzer in hospital blood bank has been increasing rapidly. We compared the ABO blood group typing results between automated analyzer IH-500 and manual method in healthy adults and patients with ABO discrepancies to provide useful information on interpretation of blood grouping results by automated analyzer. METHODS: Among healthy adults who underwent medical examinations, 400 samples (each 100 samples of A, B, O and AB type) were selected and evaluated the results and grades of blood grouping by automated and manual methods. Also, 50 samples showing ABO discrepancies among patients requested for pretransfusion test were selected and compared between two methods. As for samples with ABO discrepancies, further tests such as microscopic examination, reactivity with anti-A1 or ABO genotyping along with medical record review were performed. RESULTS: Agglutination results and grades in healthy adults were consistent between two methods. Meanwhile, 30 (60%) of ABO discrepant samples were related to rouleaux formation and their frequencies and agglutination grades were higher in automated method (Wilcoxon signed rank test, P=0.001). Results of discrepant samples caused by unexpected antibody or ABO subgroup showed no differences between two methods. CONCLUSION: IH-500 automated analyzer was considered useful for mass examination of healthy individuals. Meanwhile, considering the fact that ABO discrepancies by rouleaux formation were more frequent and stronger in automated method, it is recommended to retest their results by manual methods along with medical record review.
Adult ; Agglutination ; Blood Banks* ; Blood Grouping and Crossmatching ; Humans ; Medical Records ; Methods*

OBJECTIVETo determine the genotypes of three blood samples suspected as B subtype through DNA sequencing.

METHODSThe samples were first genotyped with PCR-SSP. Exons 6 and 7 of the ABO genes were subjected to PCR, direct sequencing, and cloned sequencing to determine the genotypes.

RESULTSSerological results of the three samples were similar, with red cells being weakly agglutinatable by anti-B and serum containing anti-B. The samples were preliminarily genotyped as B/O1. Sequencing analysis showed that all three samples contained an O allele and a 905A>G mutation of the B gene, which was previously defined as Bx02.

CONCLUSIONThrough sequencing analysis, the three samples typed as B subtype with serological testing were identified as Bx phenotype. The genotype of samples 1 and 2 was Bx02/O101, and that of sample 3 was Bx02/O102.

ABO Blood-Group System ; genetics ; Adult ; Alleles ; Base Sequence ; Blood Grouping and Crossmatching ; methods ; Exons ; genetics ; Female ; Genotype ; Humans ; Male ; Mutation ; Phenotype ; Polymerase Chain Reaction ; methods ; Sequence Analysis, DNA ; methods ; Young Adult

BACKGROUND: The use of automated systems for pre-transfusion tests is increasing in an attempt to reduce workload and the impact of human errors in blood banks. We evaluated the clinical performance of the automated blood bank systems IH-500 (Bio-Rad Laboratories, Switzerland) and VISION Max (Ortho-Clinical Diagnostics, USA) for ABO-RhD blood typing and unexpected antibody screening. METHODS: ABO-RhD blood typing was performed for 410 samples, and antibody screening was performed for 332 samples, including 15 antibody-positive samples. The results obtained from the two automated instruments were compared with those obtained using manual methods for ABO-RhD blood typing and a semiautomated method (DiaMed-ID system) for antibody screening. Additionally, both instruments were evaluated in terms of concordance rates, sensitivity, and carryover. RESULTS: The concordance rate of the ABO-RhD blood typing results between the manual methods and the two automated instruments was 100%. For antibody screening tests, the concordance rates between the semiautomated method (DiaMed-ID system) and the automated methods were 100% and 99.7% for the IH-500 and VISION Max instruments, respectively. The sole discrepant result was obtained for a sample identified as antibody-positive only on the VISION Max; the antibody was identified as anti-Le(a). The overall sensitivity of the two automated instruments was the same as or higher than that of the semiautomated method. Carryover was not observed in antibody screening. CONCLUSIONS: The IH-500 and VISION Max instruments showed reliable results for ABO-RhD blood typing and unexpected antibody screening, and can be used clinically, with confidence, for pre-transfusion tests in the blood bank.
Automation ; Blood Banks* ; Blood Grouping and Crossmatching* ; Humans ; Mass Screening* ; Methods

BACKGROUND: An automated immunohematology analyzer, DAYMATE M (DAY Medical, Switzerland), has been recently developed. The potential of this analyzer to improve test results has been evaluated. METHODS: A total of 300 blood samples from Seoul St. Mary's hospital and Incheon St. Mary's hospital were tested for ABO and RhD typing. In addition, 336 antibody screening test (AST) samples and 82 patients treated with hematopoietic stem cell transplantation (HSCT) were included. AST results by DAYMATE M were compared with those obtained by a manual method using DS-Screening II (Bio-Rad Laboratories, Switzerland) and red blood cells from Selectogen (Ortho-Clinical diagnostics Inc., USA). RESULTS: Of the 300 patients enrolled, 87, 73, 79, and 61 had type A, B, O, and AB blood, respectively. The concordance rate was 99.9% for cell typing and 97.0% for serum typing. One discordant case was classified as type B instead of AB, and six discordant serum-typing cases were type A, but classified as type AB. Among the 336 AST samples, the concordance rate was 93.2%. From 136 positive cases, six were discordant. Within the 82 HSCT-treated patients, the concordance rate for ABO blood typing was 92.2%. Among the six discordant cases, DAYMATE M typed four cases as donor type where the standard method typed them as the recipient blood type. CONCLUSIONS: The DAYMATE M automated immunohematology analyzer performs reliably for ABO and RhD typing, as well as for ASTs and on samples from patients treated with HSCT.
Blood Grouping and Crossmatching ; Erythrocytes ; Hematopoietic Stem Cell Transplantation ; Humans ; Incheon ; Mass Screening ; Methods ; Seoul ; Tissue Donors

BACKGROUND: ABO blood typing in pre-transfusion testing is a major component of the high workload in blood banks that therefore requires automation. We often experienced discrepant results from an automated system, especially weak serum reactions. We evaluated the discrepant results by the reference manual method to confirm ABO blood typing. METHODS: In total, 13,113 blood samples were tested with the AutoVue system; all samples were run in parallel with the reference manual method according to the laboratory protocol. RESULTS: The AutoVue system confirmed ABO blood typing of 12,816 samples (97.7%), and these results were concordant with those of the manual method. The remaining 297 samples (2.3%) showed discrepant results in the AutoVue system and were confirmed by the manual method. The discrepant results involved weak serum reactions (<2+ reaction grade), extra serum reactions, samples from patients who had received stem cell transplants, ABO subgroups, and specific system error messages. Among the 98 samples showing ≤1+ reaction grade in the AutoVue system, 70 samples (71.4%) showed a normal serum reaction (≥2+ reaction grade) with the manual method, and 28 samples (28.6%) showed weak serum reaction in both methods. CONCLUSIONS: ABO blood tying of 97.7% samples could be confirmed by the AutoVue system and a small proportion (2.3%) needed to be re-evaluated by the manual method. Samples with a 2+ reaction grade in serum typing do not need to be evaluated manually, while those with ≤1+ reaction grade do.
ABO Blood-Group System/*blood ; Automation ; Blood Banks ; Blood Grouping and Crossmatching/instrumentation/*methods ; Humans

OBJECTIVETo explore the molecular basis for a rare Ax13B phenotype of the ABO subtype.

METHODSSerological assays were carried out to characterize the erythrocyte phenotype of the discrepant sample. Exons 6 and 7 of the ABO gene were amplified with polymerase chain reaction and subjected to direct sequencing. The amplicons were also cloned to separate the two alleles.

RESULTSBoth A and B antigens were detected on the red blood cells of the proband, and anti-A antibody was detected in the serum. The serological phenotype of the sample was identified as AxB. DNA sequencing showed heterozygous status for 297AG, 526CG, 657CT, 703AG, 796AC, 803GC, 930GA and 940AG in exons 6 and 7. After cloning and sequencing, two alleles Ax13 and B101 were obtained. The sequence of Ax13 showed a nucleotide change (A to G) at position 940.

CONCLUSIONThe 940A>G mutation of the α-1,3-N-acetylgalactosaminyltransferase gene has resulted in the reduced expression of A antigen.

ABO Blood-Group System ; genetics ; Alleles ; Base Sequence ; Blood Grouping and Crossmatching ; methods ; Exons ; genetics ; Genotype ; Genotyping Techniques ; methods ; Heterozygote ; Humans ; Male ; N-Acetylgalactosaminyltransferases ; genetics ; Phenotype ; Point Mutation ; Sequence Analysis, DNA ; methods

The aim of this study was to establishment of known HPA genotype platelet donor data base and carry out the platelet antigen gene typing and matching in the platelet transfusion so as to prevent the production of the antibody and to avoid the platelet transfusion refractoriness. HPA of the donors and the patients were genotyped by PCR-SSP. The platelet transfusion with the same ABO type and HPA genotypes as the patient was selected and infused if the solid-phase agglutination matching was consistent. The results showed that the distribution of HPA types in Chinese Mudanjiang area had its own characteristics. HPA-15 had the greatest heterozygosity, and then HPA-3. The effective rate was 94.4% if both the HPA types and the ABO types were coincident while the effective rate was 77.8% when only ABO types were coincident. It is concluded that the distribution of HPA types in Chinese Mudanjiang area presents genetic polymorphism. The platelet transfusion with genetic typing and matching of both HPA and ABO types is an effective way to avoid production of the antibody and platelet transfusion refractoriness.
Adolescent ; Adult ; Antigens, Human Platelet ; genetics ; immunology ; Blood Grouping and Crossmatching ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Platelet Transfusion ; methods ; Young Adult

This study was aimed to establish the matching method of hemolytic test in vitro, and to guide the transfusion treatment for puerpera with acute hemolytic disease. The donor's erythrocytes were sensibilized by all the antibodies in plasma of patient in vitro and were added with complement, after incubation for 6.5 hours at 38 °C, the hemolysis or no hemolysis were observed. It is safe to transfuse if the hemolysis did not occur. The results showed that when the matching difficulty happened to puerpera with acute hemolytic disease, the compatible donor could be screened by hemolytic test in vitro. There were no untoward effects after transfusion of 6 U leukocyte-depleted erythrocyte suspension. The all hemoglobin, total bilirubins, indirect bilirubin, reticulocyte, D-dimex and so on were rapidly improved in patient after transfusion , showing obvious clinical efficacy of treatment. It is concluded that when the matching results can not judge accurately compatible or incompatible through the routine method of cross matching, the agglutinated and no-hemolytic erythrocytes can be screened by hemolytic test in vitro and can be transfused with good efficacy; the hemoglobin level can be promoted rapidly, and no untoward effects occur.
Anemia, Hemolytic ; therapy ; Blood Grouping and Crossmatching ; methods ; Erythrocyte Transfusion ; methods ; Female ; Humans ; Puerperal Disorders ; therapy ; Young Adult

The aim of this study was to investigate the effect of alanine solution as α-N-acetylgalactosaminidase enzyme reaction buffer on the enzymatic activity of A antigen. The binding ability of α-N-acetylgalactosaminidase with RBC in different reaction buffer such as alanine solution, glycine solution, normal saline (0.9% NaCl), PBS, PCS was detected by Western blot. The results showed that the efficiency of A to O conversion in alanine solution was similar to that in glycine solution, and Western blot confirmed that most of enzymes blinded with RBC in glycine or alanine solution, but few enzymes blinded with RBC in PBS, PCS or normal saline. The evidences indicated that binding of enzyme with RBC was a key element for A to O blood group conversion, while the binding ability of α-N-acetylgalactosaminidase with RBC in alanine or glycine solution was similar. It is concluded that alanine solution can be used as enzyme reaction buffer in A to O blood group conversion. In this buffer, the α-N-acetylgalactosaminidase is closely blinded with RBC and α-N-acetylgalactosaminidase plays efficient enzymatic activity of A antigen.
ABO Blood-Group System ; immunology ; Alanine ; Blood Grouping and Crossmatching ; methods ; Humans ; Solutions ; alpha-N-Acetylgalactosaminidase ; immunology