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The Frequency and Nature of Blood Group A 3
Author(s) -
Reed T. Edward
Publication year - 1964
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.1964.tb02905.x
Subject(s) - agglutination (biology) , titer , antigen , antibody , immunology , abo blood group system , immune system , fluorescence , biology , chemistry , andrology , medicine , physics , quantum mechanics
A special survey of 20,826 random blood donor specimens collected in Ontario, Canada yielded one A 3 blood while a review of blood grouping worksheets of 158,000 individuals in this area also yielded one A 3 blood. These frequencies are much lower than the frequency found in Denmark around 1940 by Gammelgaard, 44 per 10 5 , perhaps due to the present availability of high titer immune anti‐A. Elution studies on these two A 3 bloods show that both the agglutination‐positive and the agglutination‐negative cells absorb anti‐A, indicating that A 3 is not always an A 2 + O mixture as has been suggested. Fluorescent antibody studies revealed a marked cell‐to‐cell variability in fluorescence and, therefore, presumably, cell A antigen content. This finding confirms Gammelgaard's earlier report. This variability, together with a threshold value of A antigen required for agglutination, could explain the characteristic appearance of A 3 : agglutinates and free cells.