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

No abstract available.
ABO Blood-Group System/genetics ; Aged ; Agglutination Tests ; Antibodies, Anti-Idiotypic/*blood ; Erythrocyte Transfusion ; Erythrocytes/immunology ; Female ; Genotype ; Humans ; Pneumonia/diagnosis/*immunology/therapy

OBJECTIVETo detect the IgM anti-A (B) and IgG anti-A (B) antibody titers of group O healthy donors in Hainan province area, to understand the distribution of O-type blood donor IgM and IgG antibody titers and to analyze the relationship between antibody titers, so as to provide experimental evidences for the safety and feasibility of urgent transfusion of uncrossmatched group O RBCs.

METHODSGroup O whole blood sample was collected from 80 volunteers blood donors. IgM antibody titrations was performed using the immediate spin (IS) tube, and IgG antibody titration were performed using the column agglutination technique with anti-human globulin (AHG). Using two-way ANOVA, paired t-test and correlation analysis, the different types of antibodies were compared.

RESULTSThe IgM antibody titers distributed in 4-1 024, IgG antibody titer distributed in 2-2 048. Anti-A antibody titers of IgG were significantly higher than that of IgM anti-B, IgG anti-B and IgM anti-A titers (P < 0.05). There was a positive correlation bewteen IgM anti-A and anti-B, IgM anti-B and IgG anti-B, IgG anti-A and anti-B (P < 0.05).

CONCLUSIONGroup O blood donors have high antibody titers in Hainan province area, type O RBC suspensions should be first screened through screening the anti-A titer of IgG, so that can significantly improve the pass rate of O-type universal blood and reduce testing costs.

This study looked into a family involving a rare mother-child ABO blood type inconsistency and explored its genetic and molecular basis. In the family, the mother had type AB blood and the father was blood type B and they gave birth to a baby of blood type O. Their blood types were phenotypically identified by using different techniques, including micro-column gel test, immune inhibition test, absorption and elution tests. The sequences of all 7 exons of ABO allele from the core family members were determined by using PCR and clone-based sequencing. The loci of mutated gene were compared against normal human genes. The result showed that the mother's erythrocytes were agglutinable with monoclonal anti-A antibody (2+) and had agglutination reaction with anti-B antibody (4+). The mother's serum registered agglutination action with standard blood type A cells. The findings showed an ABO inconsistency. When domestic antibodies were used, the mother's erythrocytes yielded agglutination reaction with humanized anti-B serum (4+) and anti-B monoclonal antibody but were non-agglutinable with humanized anti-A serum and anti-A monoclonal antibody. Upon absorption and elution, the titer of anit-A antibody was 128 both before and after the absorption test, with no significant difference found between pre- and post-absorption values. Our results confirmed that the mother's allelic gene was type B and contained type A. The father's blood type was type B, and son's blood type was type O. Clone-based sequencing revealed that the mother carried a heterozygous gene of B101.01 (ntA640→G)/O01, which contained an M214→V mutation that could express a weak expression of antigen A, resulting in blood type AB. However, their son did not have the M214→V mutation, which yielded a false ABO-inconsistency between him and his mother. We were led to conclude that type B gene with a M214→V mutation can encode both antigen B and weak antigen B that can lead to false ABO-inconsistencies.
ABO Blood-Group System ; genetics ; immunology ; Adult ; Base Sequence ; DNA Primers ; Female ; Humans ; Maternal-Fetal Exchange ; Molecular Sequence Data ; Mutation ; Polymerase Chain Reaction ; Pregnancy ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid

BACKGROUND: Measurement of the ABO antibody (Ab) titer is important in ABO-incompatible transplantation. However, to the best of our knowledge, no standard protocol or external survey program to measure the ABO Ab titer has been established in Korea. We investigated the current status of ABO Ab titer measurements at various laboratories in Korea and the impact of the protocol provided to reduce interlaboratory variations in the methods and results of ABO Ab titers. METHODS: The Korean external quality assessment of blood bank laboratories sent external survey samples with a questionnaire to 68 laboratories across Korea for the measurement of ABO Ab titers in May 2012. After 6 months, a second set of survey samples were sent with a standard protocol to 53 of the previously surveyed laboratories. The protocol recommended incubation at room temperature only and use of the indirect antihuman globulin method for the tube test as well as and the column agglutination test (CAT). RESULTS: Several interlaboratory variations were observed in the results, technical procedures, and methods selected for measurement. We found that 80.4% laboratories hoped to change their protocol to the provisional one. Additionally, CAT showed significantly lower variation among laboratories (P=0.006) than the tube test. CONCLUSIONS: Our study provides baseline data regarding the current status of ABO Ab titer measurement in Korea. The standard protocol and external survey were helpful to standardize the technical procedures and select methods for ABO Ab titer measurement.
ABO Blood-Group System/*immunology ; Agglutination Tests/*standards ; Antibodies/*analysis ; Humans ; Immunoglobulin G/analysis ; Immunoglobulin M/analysis ; Laboratories/*standards ; Questionnaires ; Republic of Korea ; Temperature

This study was purposed to analyses the serological and molecular basis of one sample of A blood group which has anti-A. The tube method was used to detect the blood group phenotype, the genotype was amplified by PCR-SSP. The sequence of a-1-3-N-acetylgalactosaminyltransferase gene of blood group was determined by Sanger method. The results showed that serological results of blood group were discrepant. It was determined as A subtype firstly. The result of PCR-SSP showed the existence of O and A blood group gene. The sequencing result of the 6th exon of ABO gene showed the existence of c.261delG, which refers to the O gene. The specific amplification sequencing analysis was carried out on the 7th exon of the O and A blood group gene. Two mutations in the 7th exon of the A gene haplotype, c.467 C > T and c.626 G > A, four mutations in the 7th exon of the O gene haplotype, c.646T > A, 681G > A, 771C > T, 829G > A had been detected. It is concluded that a novel allelic mutation c.626 G > A in the 7th exon of A gene is explored. The Genbank access number of this novel mutation is KC690281. c.467 C > T is SNP. The combination of two allele mutation of A gene is named as a new allelic subtype A311.
ABO Blood-Group System ; genetics ; immunology ; Blood Grouping and Crossmatching ; Exons ; Female ; Genotype ; Humans ; Mutation ; N-Acetylgalactosaminyltransferases ; genetics ; Phenotype ; Polymorphism, Single Nucleotide ; 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

Several studies have suggested that a positive lymphocyte cross-matching (XM) is associated with low graft survival rates and a high prevalence of acute rejection after adult living donor liver transplantations (ALDLTs) using a small-for-size graft. However, there is still no consensus on preoperative desensitization. We adopted the desensitization protocol from ABO-incompatible LDLT. We performed desensitization for the selected patients according to the degree of T lymphocyte cross-match titer, model for end-stage liver disease (MELD) score, and graft liver volume. We retrospectively evaluated 230 consecutive ALDLT recipients for 5 yr. Eleven recipients (4.8%) showed a positive XM. Among them, five patients with the high titer (> 1:16) by antihuman globulin-augmented method (T-AHG) and one with a low titer but a high MELD score of 36 were selected for desensitization: rituximab injection and plasmapheresis before the transplantation. There were no major side effects of desensitization. Four of the patients showed successful depletion of the T-AHG titer. There was no mortality and hyperacute rejection in lymphocyte XM-positive patients, showing no significant difference in survival outcome between two groups (P=1.000). In conclusion, this desensitization protocol for the selected recipients considering the degree of T lymphocyte cross-match titer, MELD score, and graft liver volume is feasible and safe.
ABO Blood-Group System/immunology ; Adult ; Antibodies, Monoclonal, Murine-Derived/therapeutic use ; Desensitization, Immunologic/*methods ; End Stage Liver Disease/surgery ; Female ; Graft Rejection/immunology ; Graft Survival/*immunology ; Histocompatibility Testing ; Humans ; Liver/surgery ; *Liver Transplantation ; Living Donors ; Male ; Middle Aged ; Plasmapheresis ; Preoperative Care ; Retrospective Studies ; Severity of Illness Index ; Survival Rate ; T-Lymphocytes/*immunology ; *Transplant Recipients

BACKGROUND: Detection methods for ABO antibody (Ab) titers vary across laboratories, and the results are different depending on the method used. We aimed to compare titer values using different detection methods for the measurement of ABO Ab titers. METHODS: For ABO Ab detection, pooled group A or B red blood cells (RBCs) were reacted with each of 20 sera from blood groups A, B, or O without dithiothreitol treatment. The room-temperature (RT) incubation technique and the indirect antiglobulin test (IAT) were used in the tube test and gel card test. Flow cytometry (FCM) was performed by using anti-IgM and anti-IgG Abs. RESULTS: Regardless of the blood groups tested, the FCM assay with anti-IgM showed the highest titer compared to the tube test and gel card test with RT incubation in both. The tube test with IAT showed a higher titer than the gel card test with IAT (Gel-IAT) or FCM with anti-IgG in blood group A and B, while Gel-IAT showed the highest titer relative to the other tests, only for the anti-A Ab in blood group O. CONCLUSIONS: There were significant differences in the titers depending on the detection method used, and each method showed a different detection capacity for each ABO Ab depending on the ABO blood group tested. Therefore, caution should be exercised in interpreting ABO Ab titer results, taking into consideration the detection method used and the blood group.
ABO Blood-Group System/*immunology ; Adult ; Aged ; Agglutination Tests/instrumentation/*standards ; Antibodies/*analysis ; Antibodies, Anti-Idiotypic/analysis ; Erythrocytes/chemistry/metabolism ; Female ; *Flow Cytometry ; Humans ; Male ; Middle Aged ; Temperature

No abstract available.
ABO Blood-Group System/immunology ; Agglutination Tests ; Alleles ; Base Sequence ; Blood Group Antigens/*genetics/immunology ; Chimerism ; Exons ; Female ; Genotype ; Humans ; Infant ; Male ; Microsatellite Repeats/genetics ; Pedigree ; Republic of Korea ; Sequence Analysis, DNA ; Twins, Dizygotic