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BACKGROUND: Examples of group B red cells that react weakly or not at all with anti-B have been described. Subgroups of B such as B3, Bx, Bm, and Bel are rare and are less frequently reported. We studied the frequency of subgroups of B in our healthy blood donor population and serologically characterized and differentiated these subgroups. MATERIALS AND METHODS: The 9-year prospective study included 84,534 healthy blood donors. Initial blood grouping and antibody screening of all donor samples were performed using automated solid-phase assay. Any sample showing blood group discrepancy or weaker agglutination was subjected to further immunohematological investigations. RESULTS: Among 84,534 healthy donors, “B” blood group was found in 29,190 (34.53%). Weak B phenotypes were demonstrated in 9 (0.031%) B donors. Among the 9 weak B phenotypes, B3 was the most common followed by Bm. The frequency of B3, Bm, Bx, and Bel in our blood donor population was found to be 1 in 21,133, 1 in 28,178, 1 in 84,534, and 1 in 84,534, respectively. Red cell agglutination with anti-B and anti-AB varied from Wk+ to 2+ with or without mixed-field agglutination in the B3 and Bx phenotypes. Naturally occurring anti-B of immunoglobulin M type was detected in the Bx donor. Two (22.2%) of the 9 donors were found to be nonsecretor. Adsorption-elution demonstrated “B” antigen specificity in different strengths in Bm, Bx, and Bel phenotypes. CONCLUSION: We conclude that differentiating weak subgroups of “B” by serological assays is possible to a great extent with technical expertise. Mistyping weak subgroups of B as “O” group may lead to reporting errors and wrong blood transfusion. Therefore, blood centers in developing countries including India should establish simple techniques to detect and differentiate weak subgroups and develop procedures to ensure safe blood transfusion and transplantation.

BACKGROUND: Examples of group B red cells that react weakly or not at all with anti-B have been described. Subgroups of B such as B3, Bx, Bm, and Bel are rare and are less frequently reported. We studied the frequency of subgroups of B in our healthy blood donor population and serologically characterized and differentiated these subgroups. MATERIALS AND METHODS: The 9-year prospective study included 84,534 healthy blood donors. Initial blood grouping and antibody screening of all donor samples were performed using automated solid-phase assay. Any sample showing blood group discrepancy or weaker agglutination was subjected to further immunohematological investigations. RESULTS: Among 84,534 healthy donors, "B" blood group was found in 29,190 (34.53%). Weak B phenotypes were demonstrated in 9 (0.031%) B donors. Among the 9 weak B phenotypes, B3 was the most common followed by Bm. The frequency of B3, Bm, Bx, and Bel in our blood donor population was found to be 1 in 21,133, 1 in 28,178, 1 in 84,534, and 1 in 84,534, respectively. Red cell agglutination with anti-B and anti-AB varied from Wk+ to 2+ with or without mixed-field agglutination in the B3 and Bx phenotypes. Naturally occurring anti-B of immunoglobulin M type was detected in the Bx donor. Two (22.2%) of the 9 donors were found to be nonsecretor. Adsorption-elution demonstrated "B" antigen specificity in different strengths in Bm, Bx, and Bel phenotypes. CONCLUSION: We conclude that differentiating weak subgroups of "B" by serological assays is possible to a great extent with technical expertise. Mistyping weak subgroups of B as "O" group may lead to reporting errors and wrong blood transfusion. Therefore, blood centers in developing countries including India should establish simple techniques to detect and differentiate weak subgroups and develop procedures to ensure safe blood transfusion and transplantation. [ABSTRACT FROM AUTHOR]

This case report describes a 5-year-old female with antenatally detected multi-cystic dysplastic left kidney (MCDK) who was diagnosed with moderate patent ductus arteriosus (PDA) with left to right shunt and required shunt closure under general anesthesia. During the pre-operative workup, the patient’s blood group was found to be B Rh D+ve, but there were discrepancies in the reverse grouping suggesting the presence of an irregular antibody in the patient’s serum. Further immunohematological workup identified the presence of naturally occurring anti-M antibody. The patient did not have a history of previous surgery, ICU admission, transfusion, or any significant past or family history. This case highlights the importance of immunohematological workup and crossmatching in patients requiring blood transfusions and also the presence of naturally occurring antibodies (NOAs), which can complicate the transfusion process and increase the risk of hemolytic transfusion reactions (HTRs).

Weaker subgroups have the potential to cause problems in the immunohaematological testing in the blood banks. We report here a case of rare weaker subgroup A, detected during the usual ABO grouping. A 49-year-old lady exhibited a discrepancy in the forward and reverse groupings. In forward-grouping, there was a mixedfield reaction with anti-A and anti-A,B while there was no reaction with anti-B. The reverse grouping showed no reaction with the A1 and A2 cells, but the reaction with B-cell was 4+. Further tests were performed and revealed a weaker subgroup of A. It is crucial to properly investigate and resolve any discrepancy in ABO grouping before commencing transfusion to avoid any wrong blood transfusion. This case report may assist others in resolving the ABO blood group discrepancies. [ABSTRACT FROM AUTHOR]

In this study, we aimed to determine and analyze the genetic differences of the FUT1 and FUT2 genes within an individual exhibiting the Para-Bombay phenotype. Standard serological tests were conducted to analyze the ABO phenotype. The amplification of FUT1 and FUT2 genes was conducted by polymerase chain reaction and amplicons were sequenced. The determination of the ABO genotype was conducted by sequencing exons 1 to 7 of the ABO gene. The Lewis phenotype was defined as Le(a−b+); Despite this, red blood cells (RBCs) did not show signs of A, B and H antigens using the serological method utilized in this study. However, Analyses of sequencing and cloning demonstrated the existence of a FUT1 mutation at position c.658C>T and an inactive allele FUT1*01N.06 (c.551_552delAG). Genetic testing for ABO blood types was subsequently determined to be ABO*B.01/ABO*B.01 (c.297A>G; c.526C>G; c.657C>T; c.703G>A; c.796C>A; c.803G>C; c.930G>A). Heterozygosity for indel and missense mutation within the coding region of FUT1 are likely to be responsible for development of the Para-Bombay phenotype.

Introduction: The para-Bombay phenotype, or H-deficient secretor, results from different mutations of the FUT1, with or without the FUT2 mutation. Consequently, there is an absent or weak expression of the H antigen on red blood cells (RBCs). Routine ABO blood grouping for two siblings with blood group O showed discrepant results with their parental blood group AB. Fragments encompassing the entire coding region of the FUT1 and FUT2 genes were investigated. Methods: Blood and saliva specimens were collected to verify the correct ABO grouping by cell grouping, serum grouping and the hemagglutination inhibition (HI) test, respectively. The FUT1 and FUT2 genomes were identified using the whole-exome sequencing (WES) in two children's DNA blood specimens and may have caused, or been relative to, their blood group. Genetic variations of the FUT1 and FUT2 genes have been investigated in the other family members using the Sanger sequencing. Results: The serologic reaction results of the proband revealed that A, B and H antigens were absent on RBCs, and that the serum contained anti-H. However, ABH and AH antigens were present in the saliva PB1 and PB2, respectively. The probands PB1 and PB2 were assigned as AB and A blood groups, respectively. Blood genotyping confirmed that heterozygous mutations of the FUT1 gene, c.551_552delAG, were identified. Three family members, PB3, PB, and PB8, also showed normal ABO blood groups, but their genotypes were also the FUT1 mutation c.551_552delAG. Conclusions: The FUT1 mutation c.551_552delAG may result in the reduced or absent H antigen production on RBCs, which characterizes the para-Bombay phenotypes. Blood genotyping is essential if these individuals need a blood transfusion or are planning to donate blood.

Since the advent of the pandemic, ABO blood group has a role in the immunopathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Disagreement between forward and reverse typing leads to ABO discrepancy which arise either due to intrinsic problems or from the technical errors in performing the test. Here, we document the two cases of transient absence anti-A and anti-B antibodies among two COVID patients proved by serological techniques, with the photographic representation of their immunohematological workups. SARS-CoV-2 viral envelop proteins mimicking as A and B antigen expressed on red blood cells (ABOs) and anti-A and anti-B antibodies acting as viral neutralizing antibodies, possible explanation for appearance of such phenomenon among patients. The ABO blood grouping of such discrepancy patients should be cautiously reported and advised to repeat once after full recovery. Transfusion center should be prepared appropriately in case of blood component support needed among such patients.

Quantitative and/or qualitative differences in ABO phenotypes give rise to ABO discrepancies causing difficulties in establishing the accurate phenotype. These discrepant serological reactions result in significant delays in blood bank. The correct typing of the blood group is imperative to prevent ABO incompatibility issues. However, the discrepant results encountered in routine settings are a challenge to immunohematologists. The variants of the ABO occur very rarely particularly true for B subgroups. Here, we present a case study of a healthy blood donor, discrepant results in forward and reverse blood grouping led us to perform adsorption-elution test. The presence of anti-B in the eluate confirmed the presence of weaker variant of B antigen on the surface of red blood cells. Correct identification of blood group is mutually important for donor and recipient to prevent the occurrence of any transfusion reaction. The serologically determined weak B phenotypes, however, require further confirmation through genomic analysis.

Quantitative and/or qualitative differences in ABO phenotypes give rise to ABO discrepancies causing difficulties in establishing the accurate phenotype. These discrepant serological reactions result in significant delays in blood bank. The correct typing of the blood group is imperative to prevent ABO incompatibility issues. However, the discrepant results encountered in routine settings are a challenge to immunohematologists. The variants of the ABO occur very rarely particularly true for B subgroups. Here, we present a case study of a healthy blood donor, discrepant results in forward and reverse blood grouping led us to perform adsorption-elution test. The presence of anti-B in the eluate confirmed the presence of weaker variant of B antigen on the surface of red blood cells. Correct identification of blood group is mutually important for donor and recipient to prevent the occurrence of any transfusion reaction. The serologically determined weak B phenotypes, however, require further confirmation through genomic analysis. [ABSTRACT FROM AUTHOR]

Since the advent of the pandemic, ABO blood group has a role in the immunopathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Disagreement between forward and reverse typing leads to ABO discrepancy which arise either due to intrinsic problems or from the technical errors in performing the test. Here, we document the two cases of transient absence anti-A and anti-B antibodies among two COVID patients proved by serological techniques, with the photographic representation of their immunohematological workups. SARS-CoV-2 viral envelop proteins mimicking as A and B antigen expressed on red blood cells (ABOs) and anti-A and anti-B antibodies acting as viral neutralizing antibodies, possible explanation for appearance of such phenomenon among patients. The ABO blood grouping of such discrepancy patients should be cautiously reported and advised to repeat once after full recovery. Transfusion center should be prepared appropriately in case of blood component support needed among such patients. [ABSTRACT FROM AUTHOR]

”Auto-anti-A1” has been sparsely discussed in the literature. Only few workers in the past depicted such antibody in transfused and nontransfused patients. The current case is probably the first example of auto-anti-A1 in a healthy young blood donor who was typed as ABO Group “A1B.” The cold reacting autoantibody in the donor was serologically characterized in details and was found to be nonhemolytic. ABO discrepancy was resolved and the donor was finally typed as “A1B Negative.” Therefore, we concluded that auto-anti-A1 may be a rare cause of ABO discrepancy and its resolution is essential to confirm blood group and subsequent blood transfusion management.

Background:-ABO and Rhesus blood group system is considered as clinically significant blood group systems in transfusion practice . A feature of the ABO system is the regular occurrence of anti A and anti B in the absence of the corresponding red cell antigen. A Discrepancy exists when results of forward testing does not match with reverse testing. Blood donors and patients must be correctly ABO and Rh grouped because transfusing ABO incompatible blood transfusions which may lead even death of patient. Aims and Objectives To assess the incidence and cause of blood grouping discrepancies in Blood Bank at Tertiary care teaching hospital during Jan 2019 to December 2019. Methods : Forward and reverse grouping were performed on blood samples from inpatients,outpatients and donors during the study period. ABO discrepancies were studied with their clinical details to group their discrepancies and resolve them with suitable steps. Results: A total of 10,048 (patients and donors) who satisfied inclusion criteria were included and ABO typed among which there were 55 discrepancies were observed (15 donors and 35 patients). The problem in patients was due to expression of weak antigens. The problem in patients were due to clinical conditions, the most common being autoimmune haemolytic anaemia. Conclusions: The ABO blood group discrepancy reported in present study is 0.49%. The study helped to determine the incidence and causes of discrepancy encountered in tertiary care hospital. Discrepant results should be recorded, and resolved by suitable measures and correct ABO & Rh Blood group should be released to avoid any mismatched transfusions. [ABSTRACT FROM AUTHOR]

Introduction: The naturally occurring "Anti-M" antibody, which is usually active at temperatures below 37 °C and has no clinical significance, can lead to discrepancy in ABO blood grouping and confusion in diagnosis. Case Presentation: This paper reports the case of a 28-year-old woman whose unanticipated reaction in her reverse blood grouping was observed due to the presence of anti-M, which made interpretation of her blood group difficult. The reason for this discrepancy created an interesting case to analyze. Take-away Lesson: A laboratory should always choose the reagent that is most suitable to the profiles of patients referred to that laboratory. It should be noted that if an anti-M is found in an M+ patient with negative autocontrol, it is not correct to conclude that there is a "partial M". [ABSTRACT FROM AUTHOR]

Anti-A and anti-B antibodies are naturally occurring and develop from exposure to intestinal bacteria after age 4 to 6 months. In the laboratory, strong agglutination with A1 and B cells, or B cells only and A1 cells only, on reverse typing in a healthy person with immunocompetence is expected for patients with ABO types O, A, and B, respectively. However, absent or weak anti-A and anti-B antibodies can be observed in some clinical scenarios, such as patients with immunodeficiencies, newborns, elderly patients, and patients who have recently received bone marrow transplants. In this article, we report the cases of 2 pediatric patients with group O blood type who were receiving total parenteral nutrition (TPN) and disease-specific enteral feeds and who have strong anti-A and absent/weak anti-B. [ABSTRACT FROM AUTHOR]

The ABO system is an essential blood group in clinical transfusion medicine implicated in several human diseases. The ABO system has been investigated for over a century, with various studies exploring potential links to disease susceptibility. The study examines the possible relationship between leukemia and the distribution and the ABO blood group system discrepancy. A comprehensive review was conducted on the recommended databases to review the ABO blood groups, their association with leukemia, and the expected changes in blood groups among leukemia patients. The study highlights different kinds of leukemia, such as acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and chronic lymphocytic leukemia (CLL), their characteristics, and their relationship with ABO blood groups. The document concludes that studying ABO blood group distributions among leukemia patients showed that the most common blood group in acute leukemia is the A group, while in chronic leukemia, the O group is predominant; more studies are required. This study also confirmed an association between leukemia and ABO blood group discrepancy., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Elzein et al.)

ABO discrepancies are recognized when the reactions obtained in the forward type do not "match" the reactions obtained in the reverse type. Discrepant results are often caused by a variant ABO gene. Molecular analysis is required to confirm the type of subgroups and discrepancy. In this study ABO genotyping was performed on a series of blood donors and patients to determine their definite blood groups. We examined 100 samples with ABO discrepancies from blood donors and patients referred to Tehran Blood Transfusion Center between October 2015 and August 2016. ABO genotyping was performed on all samples with allele specific PCR for differentiation of A, B and O alleles. Exon 6 and 7 of ABO gene were sequenced to confirm the results. The genotyping of donor/patients samples with discrepant results of ABO blood typing consisted of 61 cases of A2 and A2B, 3 cases of B302 and 4 cases of Aw06. Genotyping of 6 samples that had extra antibody in their serum (AB blood group) confirmed the cell type reaction results. 6 samples that had shown a very weak reaction with anti-AB (similar to O blood group) and had no anti-A in their serum were genotyped as O1O2. Blood group genotyping laboratory provides an efficient service for evaluation of ABO discrepancies and resolve the problems encountered in serology reactions. [ABSTRACT FROM AUTHOR]

"Auto-anti-A1" has been sparsely discussed in the literature. Only few workers in the past depicted such antibody in transfused and nontransfused patients. The current case is probably the first example of auto-anti-A1 in a healthy young blood donor who was typed as ABO Group "A1B." The cold reacting autoantibody in the donor was serologically characterized in details and was found to be nonhemolytic. ABO discrepancy was resolved and the donor was finally typed as "A1B Negative." Therefore, we concluded that auto-anti-A1 may be a rare cause of ABO discrepancy and its resolution is essential to confirm blood group and subsequent blood transfusion management. [ABSTRACT FROM AUTHOR]

Anti M is considered a naturally occurring antibody that is usually active at temperatures below 37°C and is thus of no clinical significance. This antibody, if present in an individual, can lead to a discrepancy between forward and reverse ABO grouping and thus creates diagnostic difficulties for blood bank staff. We report a case of a 58-year-old lady who had an unexpected reaction in reverse grouping due to anti M that posed a problem for us in the interpretation of results of her blood group. We also reviewed the literature to find out the significance of such discrepancy in blood grouping.

Anti-M antibodies are usually of IgM, appear as cold agglutinins and are clinically insignificant. We are reporting two cases of anti-M in cases of solid tumors where the anti-M caused discrepancy in blood grouping, reacted in coombs phase of crossmatching. Anti-M in first case showed dosage effect. These antibodies can be clinical significant when detected in coombs phase, making M antigen negative coombs compatible unit transfusion imperative. [ABSTRACT FROM AUTHOR]

Bombay blood group is a rare phenotype that is characterized serologically by absence of H, A and B antigens on red cell surface and presence of corresponding antibodies in the serum. We report a case of 45-year old patient having Bombay blood group phenotype who experienced an acute reaction due to transfusion of mismatched blood unit. [ABSTRACT FROM AUTHOR]

Examines the importance of a patient's medical history in finding solutions for ABO blood typing problems. Cause of blood transfusion complications; Instance wherein a direct antiglobulin test and an elution should be performed; Reason behind the difficulty in obtaining a medical history.

The 547G>A polymorphism demonstrates significant allelic competition in people who harbor the B306 allele. We have performed the full sequencing of ABO gene in family members and measured their serum glycosyltransferase activity for demonstrating the cause of allelic competition. Genetic study including two regulatory regions and exon 1, and exons 2-7 of ABO gene demonstrated c.547G>A in exon 7 of the proband and her second son. The ABO genotype of the proband, husband, first son, and other son was ABO*A102/ABO*B306, ABO*A105/ABO*O02, ABO*A102/ABO*O02, and ABO*B306/ABO*O02 respectively. Serum glycosyltransferse B activity in the proband and her second son was lower than in normal B controls. We infer that allelic competition in the the 547G>A carrying individuals is associated with reduced activity of glycosyltransferase B., (© 2016 by the Association of Clinical Scientists, Inc.)

ABO discrepancy refers to an inconsistency between red cell and serum typings and has various causes, including hypogammaglobulinemia. IgM deficiency is a rare disorder that may accompany several conditions such as infection and autoimmune disorders. Here, we describe a case of IgM deficiency discovered during the evaluation of an ABO discrepancy in a 16-yr-old Korean boy. ABO blood grouping showed that while his cell type was O+, serum typing detected only anti-A (3+). Anti-B was not detectable at room temperature but was graded at 1+ at 4℃. ABO genotyping revealed an O/O genotype. His serum IgG, IgA, and IgM concentrations were 770 mg/dL (reference range: 800-1,700 mg/dL), 244 mg/dL (reference range: 100-490 mg/dL), and 13.5 mg/dL (reference range: 50-320 mg/dL), respectively. He was diagnosed with acute osteomyelitis on the basis of clinical presentation and imaging studies. The symptoms gradually improved within 3 weeks of treatment. However, the ABO discrepancy and IgM deficiency persisted even 6 months after recovery and lymphocyte subset analysis revealed CD19+ B cell deficiency. To the best of our knowledge, IgM deficiency detected by ABO discrepancy in a patient with acute osteomyelitis has not been reported before.