1. Chapter 05.
Rh blood group system

2. Rh blood group system
O complex, polymorphic, the second most important
O more than 50 related antigens -> D, C, E, c, e
(1) Historical Overview of the Discovery of the D Antigen
O Rh positive and Rh negative: presence or absence of the D antigen
O Rh antibody: require immune red cell stimulation (transfusion, pregnancy)
- cause adverse transfusion reaction and HDFN
- similar with antibodies made from stimulating guinea pigs and rabbits with
rhesus monkey red cells
(2) Genetics and Biochemistry
O chromosome 1
O Fig. 5-1 upper: two gene locus, one allele for RHD, four alleles for RHCE
O Fig. 5-2
O Rh antigen: polypeptide (416 amino acids, traverse membrane 12 times)
carry no carbohydrate residues
be detected only on red cell membranes
function: cation transport and membrane integrity
O Rh null: lack of Rh system antigens -> membrane abnormality
-> shorten red cell survival (stomatocyte)

3. Rh blood group system

4. Rh blood group system

5. Rh blood group system
(3) Rh Terminology
O Table 5-1
1. Fisher-Race: CDE Terminology
O Fig. 5-1 middle: three gene locus, each two alleles
2. Wiener: Rh-Hr Terminology
O Fig. 5-1 lower: one gene locus, eight alleles
O Table 5-2, Table 5-3
3. Rosenfield: Numeric Terminology
O D+, C+, E-, c+, e+ -> Rh: 1,2,-3,4,5
4. International Society of Blood Transfusion:
Standardized Numeric Terminology
O Six-digit number
- first three number: the system (004 for Rh system)
- remaining three number: antigen specificity
(correspond to the Rosenfield system)

6. Rh blood group system

7. Rh blood group system

8. Rh blood group system
(4) Determining the Genotype from the Phenotype
O phenotype determination: using anti-D, anti-C, anti-c, anti-E, anti-e
O genotype determination: based on the frequency of gene haplotypes
in a population (table 5-4, Table 5-5)
- inherited as a haplotype (Fig. 5-3)
- the probability of being Rh positive or Rh negative (Fig. 5-4)
(5) Antigens of the Rh System
1. D Antigen
O most immunogenic antigen in the Rh system
O variation of the D antigen concentration in different phenotypes
(Fig. 5-5)
- D-deletion phenotype: the most D-antigen sites
- C gene weakens the D expression if inherited on the opposite
chromosome (R2R2 > R1R1)

9. Rh blood group system

10. Rh blood group system

11. Rh blood group system

12. Rh blood group system O Weak D - Du
- D antigen is weakly expressed on the red cell
- red cells that are positive for D only by the IAT are referred to as weak D
-> when the D antigen is weakly expressed on the red cells
- table 5-6
(1) weak D: genetic
- Some RHD genes code for a weaker expression of the D antigen
common in blacks, cDe (R0) haplotype
- IAT is required
(2) Weak D: position effect
- when the C antigen is inherited in trans to the D antigen (Fig. 5-6)
(3) Weak D: partial D
- partial D: D antigen that is missing part of its typical antigenic structure
- D variant or D mosaic
- can make antibody to the part they are missing
(4) Significance of Testing for weak D
- requires testing for weak D on all donor red cells
- Rh (D) control; a reagent that consists of all additives except the D antibody
agglutination due to albumin, autoantibodies

13. Rh blood group system

14. Rh blood group system
2. Other Rh system Antigens
O table 5-7
(1) compound antigens or cis-product antigens:
the additional antigen product formed when two genes are inherited
on the same chromosome (Fig. 5-7)
- for example: c and e are inherited as a haplotype
-> c, e, f (cis-ce) antigen
(2) G antigens
- genes that code for C or D antigens: code for a G antigen
- anti-G: mimic anti-D and anti-C
- D-negative person: C+,D- red cell transfusion
-> anti-D production (actually anti-G)

15. Rh blood group system

16. Rh blood group system

17. Rh blood group system 3. Unusual Phenotypes (1) D-deletion phenotype
- written as -D- or D--
- no reaction with anti-E, anti-e, anti-C, anti-c
- deleted or nonfunctional at the RHCE site
- stronger D antigen activity (Fig. 5-4)
- anti-Rh17 (Hr0) production (Rh 17 antigen: present all red cell except -D- cells
(2) Rhnull phenotype
- have no Rh antigens
- demonstrate membrane abnormality -> hemolytic anemia
- negative for S, s, U, LW
- anti-Rh29 (total Rh) (R h29 antigen: present on all red cells except Rhnull cells
- normal regulator gene (X1r) -> (X0r): homozygous
-> Rh genes are inherited but not expressed
- amorph r
(3) Rhmod phenotype
- similar to the regulator Rhnull (XQr)

18. 1. General Characteristics
Rh blood group system
(6) Rh Antibodies
1. General Characteristics
O made by exposure to Rh antigens through transfusion or pregnancy
O IgG, bind at 37 degrees, agglutination is observed by the IAT
not associated with complement activation
O dosage effect: except anti-D
2. Clinical Considerations
(1) hemolytic transfusion reactions
(2) Hemolytic disease of the fetus and newborn
- D-positive baby vs D-negative mother
- initial pregnancy: anti-D production in mother
- subsequent pregnancy: anti-D -> placenta -> hemolysis of fetal RBC
- Rh immune globulin (RhIG):
immune serum globulin consisting of anti-D that is given to prevent
the formation of anti-D by D-negative individuals
- acid elution for HbF

19. Rh blood group system
(7) LW Blood Group System
O LW (Landsteiner and Wiener)
O antigen, antibody:
similar to Rh blood group system in serologic properteis
O table 5-8
- LW(a+b-): most common
- LW gene: amorph