Rh system (FSKP) Flashcards
Second most important blood group after the ABO
Rh
ISBT
International Society of Blood Transfusion
The group of red cell antigens with the greatest clinical significance or importance because of its role in hemolytic disease of the newborn and transfusion
Rh system
Rh is discovered by doing..
Blood transfusion
First human example of antibody directed at the D-antigen in a serum of a woman who’s fetus has hemolytic dx of the newborn was reported by
Levine and Stetson
IDENTIFIED the Rh blood group
Karl Landsteiner and Weiner
The red blood cells injected to the guinea pigs/rabbit came from
Rhesus monkey
Result of the rhesus monkey rbcs injected to the guinea pig/rabbit
- 85% of human RBCs were agglutinated -> Rh positive
- 15% were not agglutinated -> Rh negative
Two local celebrities who are Rh negative
Rosana Roces
Jenny de Belen
Human-produced antibody
Anti-Rh
Reported anti-Rh in serum of patient who received blood from Rh positive
Weiner and Peter
He also demonstrated Rh negative
Levine
Anti-rhesus or Anti-Rh produced by animals
Anti-LW
5 antigens or factors comprising the Rh
- Rh
- C
- E
- c
- e
Antigen that is highly immunogenic
Rh
The least immunogenic antigen
e
Non-glycosylated protein; found on red blood cell membrane
Rh-antigen
ABO is found on chromosome no.?
Chromosome no. 9
Rh is found on chromosome?
Chromosome no. 1
Low molecular weight compound - about 174,000
Rh-ag
4 nomenclatures
- Fisher-Race: DCE terminology
- Wiener: Rh-Hr terminology
- Rosenfield and coworkers: alphanumeric terminology
- International Society of Blood Transfusion Committee (ISBT): updated numeric terminology
There are 3 closely linked gene that can be inherited from both parents
Fisher-Race
Fisher-Race antigens
D C E c e
One gene at a single locus of each chromosome controls the entire Rh system
(Rh gene produced at least 3 blood factors)
Wiener
Wiener antigens
- Rho
- rh’
- rh’’
- hr’
- hr’’
Aims to bridge the confusion between Wiener and Fisher-Race
Rosenfield nomenclature
Assigned numbers to the antigens in a chronological order of discovery
Rosenfield nomenclature
Rosenfield antigen is indicated by a plus sign if?
Positive
Rosenfield is indicated by a minus sign if?
Negative
Rosenfield antigens
- Rh:1
- Rh:2
- Rh:3
- Rh:4
- Rh:5
Assigned six digit numbers to the antigens
International Society of Blood Transfusion (ISBT)
First three digits of ISBT antigen refers to the
System
Last three digits of the ISBT antigen refers to the
Specific antigen/ antigen
ISBT antigens
- 004 001
- 004 002
- 004 003
- 004 004
- 004 005
Most popular nomenclature
Wiener
Second most popular nomenclature
Fisher-Race
Fisher-Race gene complex
Rh-positive 1. Dce 2. DCe 3. DcE 4. DCE Rh-negative 5. dce 6. dCe 7. dcE 8. dCE
Antigens of Fisher-Race gene complex
Rh-positive = Antigen 1. Dce = D, c, e 2. DCe = D, C, e 3. DcE = D, c, E 4. DCE = D, C, E Rh-negative 5. dce = c, e 6. dCe = C, e 7. dcE = c, E 8. dCE = C, E
Weiner short hand designation
- Ro
- R1
- R2
- Rz
- r
- r’
- r’’
- r^y (superscript)
Genes of wiener short hand designation
Short hand designation (subscript) = gene (superscript)
- Ro = Rh^o
- R1 = Rh^1
- R2 = Rh^2
- Rz = Rh^z
- r = rh
- r’ = rh’
- r’’ = rh’’
- r^y = rh^y
Several variants of Rh antigens
- C^u
- C^x
- C^w
- E (not sure)
- D^u
Rarely found in caucasians
D^u
3 mechanisms responsible for weakened expression
- C trans
- Partial/mosaic
- Genetic weak D
Described as a position effect of C in relation to D-ag of RBC
C trans
Made up of four fragments or epitope
D-ag mosaic structure
With missing antigen
D^u variant
If antigen is complete but few in number
Weak D
Grades of D^u
- low grade D^u
- high grade D^u
Majority of antibodies are
IgG
Subclasses of IgG
IgG1, IgG2, IgG3, IgG4
Clinically significant IgG; not natural antibodies
IgG1 and IgG3
Most commonly found antibodies in immunized patients
Anti-D
Anti-G
2 closely linked gene that controls the expression of Rh proteins
- RHD
- RHCE
Responsible for the presence or absence of D antigen
RHD
Responsible for the expression of C, c, E, e antigens
RHCE
RhAG
Rh Associated Glycoprotein
RhAG is termed as
Co-expressor
When mutations in RhAG gene occur, it can result in
Missing or significantly altered RHD and RHCE proteins
Rh deficiencies
- Rh deletion
- Rh null
- Rh mod
Represented by dash; C and E are missing (D–/D–)
Rh deletion
Individuals who lack all Rh antigens on their RBCs
Rh null
Two different genetic mechanisms of Rh null syndrome
- Regulator type
2. Amorphic type
Mutation occurs in the RHAG gene
Regulator-type Rh null syndrome
Mutation in each of the RHCE genes inherited from each parent and the common deletion of the RHD gene found in most D-negative individuals
Amorphic-type Rh null syndrome
Have partial suppression of RH gene expression caused by mutations in the RHAG gene
Rh mod
Varieties of Rh antibodies
- First order Rh antibodies
- Second order Rh antibodies
- Typical Rh antibodies
Saline agglutinins; bivalent antibodies; complete antibodies
Antibody reacts strongly with saline, less strongly in a protein
First order Rh antibodies
Antiglobulin antibodies
Antibodies will react with specific antigen
Typical Rh antibody
Reacts strongly with most Rh-positive RBCs
Less raction in Rh-negative
Anti-LW