OBJECTIVE: To explore the serological and molecular genetic characteristics of a family with subtype B(A)06. METHODS: A neonatal hyperbilirubinemia patient who was treated at Henan Children's Hospital on June 15, 2023 due to "yellowing of the skin and gradual aggravation", and was found to have inconsistent ABO forward and reverse typing through blood type testing, was selected as the research subject. Six milliliters of peripheral blood were collected from the newborn and her family members (grandfather, grandmother, father, mother and aunt) respectively. ABO blood group identification was performed by the blood group serological method. Human genomic DNA was extracted using the nucleic acid extraction or purification reagent BT-01. ABO gene exons 2 to 7 were amplified by PCR. The PCR-specific products that were successfully amplified were sequenced by Sanger method. Taking ABO*A1.01 as the reference sequence, the ABO gene sequences of the newborn and her family members were analyzed to determine the ABO genotype. The procedures followed in this study were approved by the Ethics Committee of Henan Children's Hospital (Ethics No.: 2022-K-L036). RESULTS: The serological results of ABO blood group showed that the newborn, her grandfather, father and aunt were all incompatible with the forward and reverse typing. The blood group phenotype of the newborn was AwB or B(A), the blood group phenotype of the grandfather was A2B or B(A), the blood group phenotype of the father and aunt were A2B, and the blood group phenotype of the grandmother and mother were both O. The screening test results of hemolytic disease of the newborn showed that the free test detected IgG anti-A1 antibody, while the elution test, direct antiglobulin test and antibody screening results were all negative. The Sanger sequencing results showed that the newborn had variations of c.261delG, c.297A>G, c.526C>G, c.657C>T, c.703G>A, c.796C>A and c.930G>A. Her grandfather had variations of c.297A>G, C.526C>G, c.657C>T, c.703G>A, c.796C>A, c.803G>C and c.930G>A. Her grandmother had variations of c.106G>T, c.188G>A, c.189C>T, c.220C>T, c.261delG, c.297A>G, c.646T>A, c.681G>A, c.771C>T and c.829G>A. Her father and aunt had variations of c.106G>T, c.188G>A, c.189C>T, c.220C>T, c.261delG, c.297A>G, c.526C>G, c.646T>A, c.657C>T, c.681G>A, c.703G>A, c.771C>T, c.796C>A, c.829G>A and c.930G>A. Her mother had variations of c.106G>T, c.188G>A, c.189C>T, c.220C>T, c.261delG, c.297A>G, c.646T>A, c.681G>A, c.771C>T, and c.829G>A.The genotype of the newborn was ABO*BA.06/ABO*O.01.01, her grandfather was ABO*BA.06/ABO*B.01, her grandmother was ABO*O.01.02/ABO*O.01.02, her father and aunt were ABO*BA.06/ABO*O.01.02, and her mother was ABO*O.01.01/ABO*O.01.02. The ABO*BA.06 allele of the newborn, grandfather, father and aunt was caused by the c.803C>G variation in exon 7 based on the ABO*B.01 allele. The ABO*BA.06 allele can be stably inherited in this family. CONCLUSION The blood type of neonatal patients with B(A)06 subtype can be accurately determined by gene sequencing technology. If the forward typing is ≤ 3+ agglutination intensity in newborn ABO blood group identification, the reason should be carefully analyzed, and the molecular biology technology and family gene sequencing results should be used to jointly determine if necessary.
Humans ; ABO Blood-Group System/genetics* ; Female ; Pedigree ; Male ; Infant, Newborn ; Asian People/genetics* ; Genotype ; China ; Blood Grouping and Crossmatching ; Hyperbilirubinemia, Neonatal/blood* ; East Asian People

OBJECTIVE: To report the blood group antigen and antibody specificity identification methods for a patient with high-frequency antibodies, and the process of finding and providing compatible blood for the patient. METHODS: A patient sent from the Blood Transfusion Department of Shanxi Provincial People's Hospital to Blood Transfusion Technology Research Laboratory of Taiyuan Blood Center in November 2022 was selected for the study. Classical serological methods were used to determine the patient's blood type, screen for unexpected antibodies, identify antibodies, and perform crossmatching. High-frequency antibody identification was carried out using red blood cells treated with various enzymes. Blood group genotyping was conducted using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF) and Sanger sequencing. Multiple strategies were employed to address the patient's blood source problem. The study was approved by the Medical Ethics Committee of Taiyuan Blood Center [Ethics No. 2024 Ethics Review No.(2)]. RESULTS: The patient's blood type was B, RhD positive. Initial screening of the patient's serum with multiple screening cells and antibody identification cells in saline medium was negative, but positive in antiglobulin medium. The patient's serum showed varying reaction intensities with red blood cells treated with different enzymes. MALDI-TOF mass spectrometry and Sanger sequencing revealed a homozygous nonsense variant c.376C>T (p.Gln126Ter) in the ABCG2 gene, resulting in the Jr(a-) phenotype. During family donor selection, the patient's son was found to have a heterozygous variant c.376C>T (p.Gln126Ter), and another heterozygous variant c.421C>A (p.Gln141Lys), which predicted a Jr(a+w) phenotype. Crossmatch tests confirmed the compatibility of blood from the patient's son, which was used to address the urgent blood requirement. Later, rare blood from a Jr(a-) donor from the Guangzhou Blood Center was used for the patient's ongoing treatment, saving the patient's life. CONCLUSION Combining classic serological testing with blood group gene typing techniques successfully identified the rare Jr(a-) blood type and high-frequency anti-Jra antibodies. Enzyme-treated red blood cell identification methods confirmed the presence of anti-Jra antibodies. By searching within the family and seeking help from other blood centers, compatible blood was found. This approach may provide insights for resolving similar complex blood matching problems in the future.
Humans ; Blood Grouping and Crossmatching/methods* ; Blood Group Antigens/immunology* ; Blood Transfusion ; Male ; Isoantibodies/blood* ; Female ; Genotype

Objective To precisely identify the para-Bombay blood types in cancer patients at our hospital, establish a robust system for the identification of challenging blood types in our laboratory, and provide a foundation for precise transfusion practices. Methods We retrospectively analyzed the blood type results of 91 874 cancer patients from January 1, 2019, to December 31, 2023. Conventional serological methods were used to screen for blood types, and suspected para-Bombay blood types were identified. Further analysis was performed using Pacific Biosciences (PacBio) single-molecule real-time sequencing and Sanger sequencing was used to determine the genotypes of the ABO, FUT1, and FUT2 genes. Results Eight cases of para-Bombay blood type were confirmed through serological and molecular biological methods. The FUT1 genotypes identified were: 5 cases of h1h1 (homozygous mutation 551_552delAG) and 3 cases of h1h2 (compound heterozygous mutations of 551_552delAG and 880_882delTT). The FUT2 genotypes identified were: 2 cases of Se³⁵⁷/Se^{357, 716} and 4 cases of Se³⁵⁷/Se³⁵⁷. Additionally, one sample revealed a novel heterozygous mutation, 818C>T, in exon 7 of the ABO gene, which was confirmed by PacBio sequencing to be located on the O haplotype. Conclusion PacBio sequencing technology demonstrates significant advantages in analyzing the haplotypes of para-Bombay blood type genes. This approach supports the establishment of a robust system for the identification of challenging blood types and provides novel evidence for precise transfusion practices in cancer patients.
Humans ; Neoplasms/genetics* ; Fucosyltransferases/genetics* ; ABO Blood-Group System/genetics* ; Male ; High-Throughput Nucleotide Sequencing/methods* ; Galactoside 2-alpha-L-fucosyltransferase ; Female ; Retrospective Studies ; Genotype ; Middle Aged ; Blood Grouping and Crossmatching/methods* ; Adult ; Mutation ; Aged

OBJECTIVE: To analyze the RHD genotyping and sequencing results of RhD serology negative samples in the clinic, and to further explore the laboratory methods for RhD detection, in order to provide a basis for clinical precision blood transfusion. METHODS: A total of 27 200 whole blood samples were screened for RhD blood group antigen using microcolumn gel card method.Serologic RhD-negative confirmation tests were performed on blood samples that were negative for RhD on initial screening using three different clonal strains of IgG anti-D reagents. The 10 exons of the RHD gene on chromosome 1 were also analyzed by PCR-SSP to determine RHD genotyping.When the PCR-SSP method did not yield definitive results, the RHD gene of the sample was analyzed by the third-generation sequencing. RESULTS: The results of the initial screening test by the microcolumn gel card method showed that 136 of the 27 200 samples were RhD-negative, of which 86 underwent RhD-negative confirmation testing and RHD genotyping, 88.37% (76/86 cases) of the RhD-negative confirmation test results were negative for the three anti-D reagents, and the results of RHD genotyping showed that 67.44% (58/86 cases) of the cases had a complete deletion of 10 exons, and the remaining 28 cases were RHD*711delC (1 case), RHD*D-CE(1-9)-D (1 case), RHD*D-CE(2-9-)D (2 cases), RHD*D-CE(3-9)-D (4 cases), RHD*DEL1 (c.1227G >A) mutation (16 cases), RHD*weak partial 15(845G >A) mutation (3 cases), and a mutation of c.165C >T base was found in 1 sample by three-generation sequencing. CONCLUSION RHD genotype testing of samples that are serologically negative for RhD antigen shows that some of the samples have RHD gene variants, not all of which are total deletions of RHD, suggesting that there are some limitations of the serologic method for RhD detection. Due to the polymorphism of the RHD gene structure, different RhD variants present different serologic features, which need to be further detected in combination with molecular biology testing, especially for the identification of Asian-type DELs, which is important for clinical precision blood transfusion.
Humans ; Rh-Hr Blood-Group System/genetics* ; Genotype ; Polymerase Chain Reaction ; Exons ; Blood Grouping and Crossmatching

OBJECTIVE: To analyze the origin and influencing factors the titer of ABO blood group antibody in neonates. METHODS: A total of 303 newborn blood samples collected in our hospital from August 2023 to March 2024 were selected for the detection of ABO blood group settings and the determination of the total titers of IgG and IgM blood group antibodies in plasma. IgM antibodies were treated with dithithreitol (DTT) to determine the titers of IgG antibodies. The total titer of the blood group antibody was compared with that of the IgG antibody. The clinical data of mothers and newborns were collected, and the correlation between the antibody titer and these clinical data was analyzed. RESULTS: Among the 303 newborn specimens, 14 cases (4.62%) were identified to possess blood group antibodies. The influence of the maternal ABO blood group on the generation of high-potency blood group antibodies in newborns was observed to follow the order of O>B>A>AB, with a significant statistical difference ( P < 0.01). Of the 123 (40.59%) newborns born to mothers of type O, 121 (98.37%) had blood group antibody titers > 2. Of the 20 (6.60%) newborns born to mothers of type AB, all 20 (100.00%) had blood group antibody titers < 2. Among 89 (29.37%) mothers of type A and 71 (23.43%) mothers of type B, the titer of 100% newborn blood group antibody was less than 2, when the newborn blood group was incompatible with the mother's blood group; the titer of the newborn blood type antibody was higher or lower, when the newborn blood type was compatible with the mother's blood type. The titer of the newborn blood group antibodies is related to the number of pregnancies of the mothers and has no association with other clinical data (such as the mother's number of obortions), the number of production, fetal gestation age. CONCLUSION The majority of ABO blood group antibodies in neonates are IgG antibodies from the mothers, and few are produced by the neonates themselves. In some neonates, IgG anti-A and/or anti-B can agglutinate with anti-stereotyped cells at room temperature. The maternal ABO blood type is the primary factor influencing the titer of the newborn blood type. The number of maternal pregnancies is a factor affecting the high titer ABO blood group antibodies in newborns.
Humans ; Infant, Newborn ; ABO Blood-Group System/immunology* ; Female ; Immunoglobulin G/blood* ; Immunoglobulin M/blood* ; Pregnancy ; Blood Grouping and Crossmatching

OBJECTIVE: To identify the blood type of specimens from pregnant patients with difficult-to-type ABO status, and to guide clinical safe blood transfusion. METHODS: The specimens from 36 pregnant patients with suspicious ABO blood group were collected. These specimens were submitted by clinical institutions from various regions to our center's genetic testing platform from January 2021 to December 2022. The blood group phenotypes and genotypes of these specimens were identified by serological method and genetic sequencing. RESULTS: A total of 20 ABO subtypes were detected in the 36 samples, including 10 cases of BA/O, 3 cases of cisAB/O, 2 cases of A/Bw, 1 case of A2/B, 1 case of Aw/B, 1 case of BA/B, 1 case of BA/A, and 1 case of Bw/O. Additionally, 4 cases were identified as para-Bombay blood type, and no specific variations associated with abnormal phenotypes were found in the remaining 12 cases. CONCLUSION ABO subtypes interfere with ABO blood group identification in pregnant patients, and pregnancy status also affects blood group phenotype. Accurate determination of blood group genotype by genetic sequencing technology can guide clinical blood transfusion for pregnant patients, and ensure maternal and infant safety.
Humans ; Female ; Pregnancy ; ABO Blood-Group System/genetics* ; Blood Grouping and Crossmatching ; Blood Transfusion ; Genotype ; Phenotype

OBJECTIVE: Serological and molecular biological analysis of a B(A) subtype family was carried out to explore the underlying mechanism of B(A) subtype and clinical safe blood transfusion strategies. METHODS: The ABO blood type of the proband and her four family members were identified by serological methods, and serological experiments such as anti-H, anti-A1 and absorption-elution tests was added. In addition, the exons 6 and 7 of the ABO gene were sequenced by PCR-SSP (polymerase chain reaction - sequence specific primer). RESULTS: The serological results showed that the agglutination intensity of the proband, her mother and her maternal grandmother was imbalanced during forward typing, showing weak A and strong B antigens, and there were strong H antigens and their intensity were higher than that of normal B type. The results of reverse typing indicated the presence of weak anti-A1 antibodies, and human anti-A was positive in the absorption-elution test. Genetic sequencing revealed a characteristic mutation of c.700 C>G in all three individuals. The sequencing results showed that the proband was B(A)02/B01, her mother was B(A)02/O02, and her maternal grandmother was B(A)02/O01 . According to the compatibility principle, 1.5 units of type O washed red blood cells were transfused intraoperatively, resulting in no adverse reactions. CONCLUSION The c.700 C > G mutation on exon 7 is the molecular basis for the formation of B(A)02, and pedigree analysis shows that the B(A)02 allele was inherited from the proband's maternal grandmother to the proband's mother and then to the proband, showing a stable cis-inheritance pattern rather than a spontaneous mutation. For patients with B(A)02 subtype, type O washed red blood cells and type AB plasma can be transfused according to the principle of compatibility.
Humans ; ABO Blood-Group System/genetics* ; Female ; Blood Transfusion ; Blood Grouping and Crossmatching ; Pedigree ; Male ; Mutation ; Adult ; Exons

OBJECTIVE: To establish a genotyping method for Diego, MNS and Kell blood groups based on quantitative real-time PCR (qPCR) technology, and preliminarily apply it to the screening of rare blood groups in blood donors. METHODS: Blood group gene standards containing heterozygous and homozygous alleles were prepared by blood group serological and PCR-SBT methods. Specific amplification primers and hybridization probes were designed, and explore to establish the qPCR method for detecting Diego, MNS, and Kell blood group genotypes. Then the established qPCR method was used to identify blood group genotypes of 186 blood donor samples. RESULTS: A method based on qPCR technology was established to identify Dia/Dib, S/s and K/k blood group antigens. The genotyping results of the gene standard samples were consistent with the serological testing results and genotypes detected by PCR-SBT. qPCR testing of 186 samples identified 11 cases of DI*A/B heterozygosity and 19 cases of GYPB*S/s heterozygosity, and the rest were DI*B/B, GYPB*s/s, KEL*02/02 homozygosity. No rare blood group genotypes of DI*A/A, GYPB*S/S, KEL*01.01/01.01 were found. CONCLUSION The established qPCR method is suitable for genotyping on Diego, MNS and Kell blood group, and it can be used for batch screening of blood donors and the establishment of rare blood group bank.
Humans ; Genotype ; Genotyping Techniques/methods* ; Real-Time Polymerase Chain Reaction/methods* ; Blood Group Antigens/genetics* ; Kell Blood-Group System/genetics* ; Blood Donors ; Blood Grouping and Crossmatching/methods* ; Erythrocytes ; MNSs Blood-Group System/genetics*

BACKGROUND

Pre-transfusion testing is done to avoid transfusion morbidity from unexpected RBC antibodies. Available commercial kits from Western brands may not consider racial differences in antibody frequencies between East/Southeast Asians and Western populations. The limited number of blood banks in the Philippines precludes research on RBC antibody screening and identification in the country.

This study aimed to compare RBC antibody screening and identification methods in patients at a tertiary hospital in the Philippines, assess the frequency of major blood group antibodies using both techniques, and review clinical histories of discrepant and nonspecific cases.

Retrospective review showed 118 cases with both screening and identification tests using both conventional tube-based technique and column agglutination or gel-based technique. Antibody frequencies and discrepant or nonspecific results were recorded. Concordance rates were calculated, and differences between the two methods were analyzed using 95% confidence interval (95% CI). Clinical histories of discrepant and nonspecific cases were also reviewed.

The most frequent major blood group was Rh (41 cases or 34.7%), followed by MNS (34 cases or 28.8%) and Kidd (15 cases or 12.7%). The most common antibody was Anti-E (24 cases or 20.3%), followed by Anti-Mia (19 cases or 16.1%), and Anti-M and Anti-c (12 cases each, or 10.2% each). The concordance rate for screening was statistically significant at 72%. Concordance rate for identification was 59.3%, with significant difference in identifying Anti-Mia. Clinical histories for discrepant or nonspecific cases showed previous transfusions, pregnancy, lymphoproliferative conditions, and certain medications.

Statistically significant differences between the two methods were found, with the gel-based technique identifying more Anti-Mia cases. Negative results from the tube-based method do not fully exclude Anti-Mia. These discrepancies highlight the benefit of using both methods for comprehensive RBC antibody screening and identification, done as a complement to the other.

OBJECTIVE: To establish a based method flow cytometry to identify the antigen Jka in human red blood cells (RBCs) and verify its accuracy. METHODS: A total of 96 blood samples were enrolled in the study randomly from the voluntary blood donors in Shenzhen Blood Center. The RBCs were incubated with IgG anti-Jka primary antibody, and then labeled with the secondary antibody anti-IgG-Alexa Fluor 647. The fluorescence histograms of each sample were obtained by flow cytometry. Serological agglutination test was used to compare the accuracy of flow cytometry in the detecting of antigen Jka, while PCR-SSP and gene sequencing genotyping were used to verify the accuracy of flow cytometry in the detecting of the antigen in human RBCs. RESULTS: The results of flow cytometry for antigen Jka in human RBCs were consistent with those from serological tests. Samples that demonstrated higher serological agglutination intensity also showed higher fluorescence activity, which indicate more stronger of Jka antigen. The sensitivity of flow cytometry was higher than that of serological test; especially in distinguish Jka weak and negative samples. Flow cytometric results of all samples were consistent with the genotyping results, which confirmed the accuracy of flow cytometry. CONCLUSION The study established a new flow cytometry-based method successfully for the identification of Jka antigen of Kidd blood group in human RBCs. The Kidd blood group antigen Jka of different intensities can be accurately distinguished by the technique.
Blood Group Antigens ; Blood Grouping and Crossmatching ; Erythrocytes ; Flow Cytometry ; Humans ; Immunoglobulin G ; Kidd Blood-Group System