Other blood groupsOther blood groups

Several other blood group antigens have Several other blood group antigens have been identified in humans. Some examples: been identified in humans. Some examples: MN, Duffy, Lewis, Kell. MN, Duffy, Lewis, Kell.

They, too, may sometimes cause transfusion They, too, may sometimes cause transfusion reactions and even hemolytic disease of the reactions and even hemolytic disease of the newborn in cases where there is no ABO or newborn in cases where there is no ABO or Rh incompatibility. Rh incompatibility.

Lewis Blood Group SystemLewis Blood Group System

LeLe The 7The 7thth blood groud. blood groud. ABH and Lewis Ag are much related together ABH and Lewis Ag are much related together

biochemically. Both have the same basic biochemically. Both have the same basic structure (15 Amino Acids), they are structure (15 Amino Acids), they are glycoproteins.glycoproteins.

Lewis Ag:Lewis Ag: Soluble AgSoluble Ag Production governed by two genes Le a & Le bProduction governed by two genes Le a & Le b At birth, there is no Lewis Ag.At birth, there is no Lewis Ag. It takes 3-4 years for the Ags to become strong It takes 3-4 years for the Ags to become strong

on the surface of the RBCs.on the surface of the RBCs.

Lewis Ab:Lewis Ab: Anti Le Anti Le aa

Anti Le Anti Le bb

Agglutinate blood in saline (IgM), work best at Agglutinate blood in saline (IgM), work best at 2020ooC, and fix the complement.C, and fix the complement.

Do not cause HDN of new born because:Do not cause HDN of new born because: Ag not developed yet.Ag not developed yet. IgM, can not cross the placenta.IgM, can not cross the placenta.

Bombay PhenotypeBombay Phenotype

It is an abnormal blood group. It is an abnormal blood group. Discovered in Bombay in 1952.Discovered in Bombay in 1952.

There are 3 genes, are controlled There are 3 genes, are controlled the synthesis of specific enzymes the synthesis of specific enzymes responsible for addition of single responsible for addition of single carbohydrate residues:carbohydrate residues: N. acetyl Galactoseamin= A antigen.N. acetyl Galactoseamin= A antigen. D.galagtose = B antigen.D.galagtose = B antigen. Fucose = H antigen = O blood group.Fucose = H antigen = O blood group. ? = AB blood group? = AB blood group

ABO systemABO system

It is important to be cautious in predicting the It is important to be cautious in predicting the ABO blood type of children based on the ABO blood type of children based on the phenotypes of their parents.  This is due to the phenotypes of their parents.  This is due to the fact that a third antigen (H) on the surface of red fact that a third antigen (H) on the surface of red cells can prevent the expected ABO blood type cells can prevent the expected ABO blood type from occurring.from occurring.

Normally, if an A blood type mother has an O Normally, if an A blood type mother has an O type child; the father is expected to be type O or type child; the father is expected to be type O or at least to carry the O allele (OO, AO, or BO at least to carry the O allele (OO, AO, or BO genotype).  genotype). 

The child has inherited an O allele from both parents.  The child has inherited an O allele from both parents.  However, an O blood type child can also be born to However, an O blood type child can also be born to parents who do not have the O allele if a recessive form parents who do not have the O allele if a recessive form of the allele for the H antigen also is inherited from both of the allele for the H antigen also is inherited from both parents.parents.

The H antigen is a precursor to the A and B antigens.  The H antigen is a precursor to the A and B antigens.  For instance, the B allele must be present to produce the For instance, the B allele must be present to produce the B enzyme that modifies the H antigen to become the B B enzyme that modifies the H antigen to become the B antigen.  It is the same for the A allele.  However, if only antigen.  It is the same for the A allele.  However, if only recessive alleles for the H antigen are inherited (hh), as recessive alleles for the H antigen are inherited (hh), as in the case above, the H antigen will not be produced.  in the case above, the H antigen will not be produced.  Subsequently, the A and B antigens also will not be Subsequently, the A and B antigens also will not be produced.  The result is an O phenotype by default since produced.  The result is an O phenotype by default since a lack of A and B antigens is the O type.  a lack of A and B antigens is the O type. 

This seemingly impossible phenotype result has been This seemingly impossible phenotype result has been referred to as a referred to as a Bombay phenotypeBombay phenotype because it was first because it was first described in that Indian city.described in that Indian city.

There are 2 different terms are used to describe these antigens.:

Weiner,s Ag,s ( Rho, rh’, rh”, hr’, and hr” ).

Fisher & Race Ags ( D, C, E, c’, and e’ ). The most important Ags in weiner is

( Rho ) The most importnant Ags in fisher and

race is ( D )

Antigens of rhesus blood Antigens of rhesus blood groupgroup

Rhesus (Rh) blood grouping systemRhesus (Rh) blood grouping system

Antigens:Antigens: This is one of the most important blood grouping systems.This is one of the most important blood grouping systems. Named because it was first discovered in rhesus monkeysNamed because it was first discovered in rhesus monkeys In 1940 Landsteiner and Wiener showed that antibodies In 1940 Landsteiner and Wiener showed that antibodies

produced against the rhesus monkey RBCs agglutinated produced against the rhesus monkey RBCs agglutinated RBCs of 85% of a human population. RBCs of 85% of a human population.

The antibodies were directed against a molecule called the The antibodies were directed against a molecule called the rhesus (Rh) antigen, and individuals possessing it were rhesus (Rh) antigen, and individuals possessing it were called Rh positive. called Rh positive.

Natural antibodies against the Rh antigens do not occur. Natural antibodies against the Rh antigens do not occur.

The gene product is identified as the RhD The gene product is identified as the RhD antigen or D antigen. antigen or D antigen.

Rh system is very complex, and our present Rh system is very complex, and our present understanding is based on the Fisher understanding is based on the Fisher system.system.

Three genes making up Rhesus antigens: C, Three genes making up Rhesus antigens: C, D, and E, found on chromosome 1, the D Ag D, and E, found on chromosome 1, the D Ag is the most important one.is the most important one.

There are two possible alleles at each locus: There are two possible alleles at each locus: c or C; d or D; and e or E. c or C; d or D; and e or E.

One haplotype consisting of c/C, d/D, e/E is inherited One haplotype consisting of c/C, d/D, e/E is inherited from each parent, and the resulting Rhesus type of from each parent, and the resulting Rhesus type of the individual depends on their inherited genotype, the individual depends on their inherited genotype, this will lead to the following genotypes CDe, cDE, this will lead to the following genotypes CDe, cDE, cde, cDe, Cde, cdE, CdE, cde. cde, cDe, Cde, cdE, CdE, cde.

If an individual's Rh genotype contains at least one of If an individual's Rh genotype contains at least one of the C, D, E antigens, they are Rhesus positive. the C, D, E antigens, they are Rhesus positive.

Only individuals with the genotype cde/cde (rr) are Only individuals with the genotype cde/cde (rr) are Rhesus negative.Rhesus negative.

The most common Rh antibody is anti-D, but it is The most common Rh antibody is anti-D, but it is possible to form antibodies to c, C, e, and E as well, possible to form antibodies to c, C, e, and E as well, and to form combinations of antibodies. There is no and to form combinations of antibodies. There is no anti-d.anti-d.

Other Rh Ags:Other Rh Ags:

Cw Ag:Cw Ag:

Very rare, and can causes HDN, and HTR.Very rare, and can causes HDN, and HTR. G Ag.G Ag. DDuu Ag: it is an important Ag, which must Ag: it is an important Ag, which must

be regarded as D Ag. in Nigeria, 8% of the be regarded as D Ag. in Nigeria, 8% of the people type as D-, are Dpeople type as D-, are Duu. Very strong Anti-. Very strong Anti-D Ab should be used to detect DD Ab should be used to detect Duu Ag. Ag.

Antibodies to the Rh system:Antibodies to the Rh system:

No naturally occurring.No naturally occurring. All the Ab are immune IgG Abs.All the Ab are immune IgG Abs. All the six Ags will produce immune Abs when All the six Ags will produce immune Abs when

given to people not from the same Rh group.given to people not from the same Rh group. D > c > E > e > CD > c > E > e > C Abs can cause HDN and HTR.Abs can cause HDN and HTR.

In any of the 4 ABO groups, a In any of the 4 ABO groups, a person can be Rh positive or Rh person can be Rh positive or Rh negative, meaning that a person’s negative, meaning that a person’s blood can be classified as one of 8 blood can be classified as one of 8 possible typespossible types

(O+, O-, A+, A-, B+, B-, AB+, AB-). (O+, O-, A+, A-, B+, B-, AB+, AB-).