ABO Blood Groups

ABO Blood GroupsABO . vwf ABO . 9 . CFU-E . .

A1: H:

Dolichos biflorus

Lotus tetragonolobus

Ulex europaeus

Bombay & paraBombayBombay and paraBombay are two rare null phenotypes characterized by an absence of all ABH antigens on RBCs. In the classic Bombay phenotype (O), neither AB nor H antigens are present on RBCs or in secretions. ParaBombay also shows few or no ABH antigens on RBCs,sometimes accompanied by normal expression of ABH antigens in secretions and body fluids.

Molecular Biology

Several ABO subtypes are also the result of mutations at the ABO gene locus, including singlenucleotide polymorphisms (SNPs) and nonsense, frameshift, and translationinitiator mutations.

For example, the A2 and Ael phenotypes are associated with a single nucleotide deletion (nucleotide 1060) and frameshift, resulting in the loss of a stop codon and synthesis of a longer A enzyme with decreased enzyme activity.

Single point mutations appear to be responsible for the decreased enzyme activity of A3, Ax, Afinn,Aend, B3, Bx ,Bv alleles.

The cisAB and B(A) alleles, which can synthesize both A and B antigens, are molecular chimeras with characteristics of both A and B gene consensus alleles.

acquired BThe acquired B phenotype,on the other hand, is an acquired enzymatic modification of group A1 red cells in vivo. The acquired B phenotype usually occurs in the setting of bacterial infection or cancer and reflects enzymatic deacetylation of group A antigen to form a Blike antigen on RBCs.

ABO AntibodiesABO antibodies are reciprocal.ABO antibodies are weak or absent in the sera of newborns until 36 months of age. Adult levels of ABO antibodies are reached by 510 years of age and decrease only slightly with advancing age. Most naturally occurring ABO antibodies are of IgM isotype, although IgA and IgG antibodies with ABO specificity are also present.ABO antibodies can fix complement and can cause hemolysis in vivo and in vitro.

ABO AntibodiesABO antibodies are naturally occurring.Defects in humoral system induced defects in ABO antibodies production. AntiA1 is a naturally occurring antibody found in the sera of some A2, A2B, and other weak A subtypes.AntiH is usually a benign, naturally occurring antibody in the sera of A1 and A1B nonsecretors. AntiA,B is found exclusively in group O individuals and appears to recognize an epitope common to both A and B antigens.

Anti A1 A Whartons Jelly cold Ab ) Rouleaux ( Ab ABO 4-6 Ab prozone wiskott- aldrich syndrome bruton

T ,TK, Th, VA Arachis hypogeaAg TArachis Griffonia..Ag TK

HSCSalvia horminum Salvia sclerea Soja Dolichos biflorus.Ag Tn

Salvia horminum Glycine soja max Dolichos biflorus.Ag Cad

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