RARE SUBGROUP OF BLOOD GROUP A IN FIRST-TIME BLOOD DONOR
Keywords:
ABO blood group system, subgroup, Ael, ABO genotyping, AEL.02Abstract
Introduction: A subgroup is a phenotype with variations in the structure or in the number of antigens on the red blood cell membrane. Blood group A has 20 subgroups, of which А1 and А2 are the most common. Other subgroups of blood group A are: А3, Ах, Аend, Am, Ay and Ael.
Aim: To show the importance of Ael subgroup because it is rare and causes ABO discrepancy. To emphasize the importance of using two techniques, serological and molecular, to confirm it.
Materials and methods: A blood sample was collected from the donor in a tube containing anticoagulant. In microgel cards, 50 μl of examined red blood cells were pipetted for forward typing, and 50 μl of examined plasma together with A1 and B red blood cells were pipetted for reverse typing. These microgel cards were incubated at 4oС and 37oС. Adsorption-elution test was performed. DNA was extracted from peripheral blood with Promega kit. ABO genotyping was performed using the RT PCR BAG ABO ERY Q kit. The interpretation of the results was done with PlexTyper.
Results: The molecular analysis detected ABO*А1.01/О1.01.01 genotype that indicates A1 blood group. The A antigen was confirmed with the adsorption-elution test. Absence of agglutination with anti-A and anti-B reagents and presence of an irregular anti-A1 antibody was detected with serological tests. The serological tests refer to Ael subgroup.
Conclusion: Subgroups of the ABO blood group system are significant because they lead to discrepancies. To resolve these discrepancies, serological and molecular techniques are used.
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Copyright (c) 2026 Meri Milchevska, Emilija Velkova, Tatjana Makarovska-Bojadzieva, Anita Hristova-Dimcheva, Violeta Dejanova-Ilijevska, Elena Petkovic, Elena Ristovska, Bojan Todorovski, Simona Stojanovska
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