Joshi SR, Kanani AN, Senjaliya SB, Rajapara MM. A
novel observation on grouping anomaly: The phenomena mimicking the B
el genetic variant of the ABO blood groups.
Asian J Transfus Sci 2021;
15:12-15. [PMID:
34349451 PMCID:
PMC8294441 DOI:
10.4103/ajts.ajts_64_19]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/18/2020] [Accepted: 10/24/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND:
Discrepancy in “forward/reverse” grouping leads to confusion in assigning ABO group to a person. It could be genetic in nature and classified according to the presence/absent of antigen on red blood cell (RBC) vis-a-vis corresponding alloantibody in plasma.
AIM:
The aim of the study was to investigate the grouping anomaly found in a recently delivered woman who required transfusion.
MATERIALS AND METHODS:
A standard protocol for investigation was followed.
RESULTS:
A 27-year-old female, gravida 4, para 3, was grouped O on forward grouping, but her serum did not agglutinate Group B RBCs tested. Absorption-elution study gave an active eluate from her sensitized RBCs with anti-B or anti-A+B. Saliva showed H, but no B antigens indicating to her Bel phenotype. However, 2-week latter in the follow-up study, her serum revealed a presence of complement binding high titer anti-B. The problem of missing anti-B on the previous occasion was attributed to hemagglutination inhibition caused by accumulated complement macromolecules on RBCs that gave rise to physical hindrance in the formation hemagglutination clumps.
CONCLUSION:
The unusual case of erroneous reversed grouping was attributed to complement-mediated hemagglutination inhibition. The positive eluate obtained from sensitized RBCs of the mother was considered to be due to a contamination of fetal RBCs in maternal circulation entered during her postpartum phase of pregnancy. It could also be due to a conversion of H to B antigen no matter in trace amount by the fetal B group-specific transferase percolated into maternal circulation.
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