Rh BLOOD GROUP (004)

Question 1

The Rh blood group was discovered by _________ and __________ in 1940

Answer 1

Karl Landsteiner and Alex Weiner

Question 2

Inheritance of Rh blood group:

Answer 2

Codominant alleles

Question 3

Rh genes:

Answer 3

RhD gene - Chr 1
RhCE gene - Chr 1
RhAG gene - Chr 6

Question 4

RHD gene expresses what antigen(s)?

Answer 4

D antigen

Question 5

RHCE gene expresses what antigen(s)?

Answer 5

D, C, c, E, e antigens

Question 6

RHAG gene expresses what antigen(s)?

Answer 6

Rh-associated glycoprotein of Rh antigens; co-expresser of Rh antigen

Question 7

Nomenclatures of Rh Blood Group:

Answer 7

Fisher-Race
Wiener
Rosenfield
ISBT

Question 8

Rh D nomenclature that has 5 Rh antigens; d = absence of D Ag

Answer 8

Fisher-Race

Question 9

Rh D nomenclature that has 8 agglutinogens with equivalent blood factors:

Answer 9

Wiener

Question 10

Rh D nomenclature that has no genetic basis; presence/absence of Ag

Answer 10

Rosenfield

Question 11

Rh D nomenclature that is machine readable; uniform nomenclature:

Answer 11

ISBT (International Society of Blood Transfusions)

Question 12

Fisher-Race terminologies

Answer 12

Dce
DCe
DcE
DCe
dce
dCe
dcE
dCE

Question 13

Wiener blood factor terminologies:

Answer 13

Rho hr’ hr’’
Rho rh’ hr’’
Rho hr’ rh’’
Rho rh’ rh’’
hr’ hr’’
rh’ hr’’
hr’ rh’’
rh’ rh’’

Question 14

Agglutinogens (Wiener Haplotype terminology)

Answer 14

Ro
R1
R2
Rz
r
r’
r’’
r^y

Question 15

Rosenfield terminology:

Answer 15

Rh1 —> D
Rh2 —> C
Rh3 —> E
Rh4 —> c
Rh5 —> e

Question 16

ISBT terminology:

Answer 16

004 001 —-> D
004 002 —-> C
004 003 —-> E
004 004 —-> c
004 005 —-> e

Question 17

What is the most common haplotype in Asia?

Answer 17

DCe, R1, Rho rh’ hr’’ (70%)

Question 18

Testing for Weak D utilizes the principle of:

Answer 18

Indirect Antiglobulin Testing (IAT)

Question 19

Testing for Weak D is required for:

Answer 19

• Blood donors
• Babies born from Rh D-negative mothers

Note: Recipients of donated blood don’t require weak D testing

Question 20

Reasons for Weak D testing:

Answer 20

Genetic Weak D
- Fewer D antigen present
- Quantitative problem

C trans
- Position effect
- D is trans to C

D mosaic/Partial D
- Missing portion of D Ag
- Qualitative problem

Question 21

Rh antigens composition:

Answer 21

• Non-glycosylated proteins
• D is the major Rh Ag and the immunogenic

Question 22

Arrangement from most immunogenic to least immunogenic Rh D antigens:

Answer 22

D > c > E > C > e

Question 23

Rh antibodies composition:

Answer 23

• IgG immune antibodies
• DO NOT activate complement (extravascular RBC lysis)
• Reactivate at 37C and AHG phase (Clinically significant - may cause HTR and HDN)

Question 24

Lacks all Rh antigens; demonstrates mild compensated hemolytic anemia, increase in Hb F:

Answer 24

Rh null syndrome (—/—)

Question 25

What red cell shape abnormality (poikilocytosis) is associated with Rh null syndrome?

Answer 25

Stomatocytes

Question 26

Partial suppression of Rh gene; features similar to Rh null but less severe:

Answer 26

Rhmod

Question 27

No C/c or E/e reactivity; unusually strong D expression:

Answer 27

Exaled D (D–/D–)

Question 28

Originally considered an allele at the C/c locus:

Answer 28

C^w

Question 29

Compound antigen: c and e are in cis position:

Answer 29

f antigen

When the c and e alleles are in the cis position, they are on the same chromosome and form a compound antigen called “f”. This means that the f antigen is only expressed when both the c and e alleles are present on the same haplotype.

Here are some things to know about the f antigen:

Anti-f antibody
The anti-f antibody is produced when an individual is exposed to the f antigen.

Transfusion
Patients with anti-f who need a transfusion can receive blood units that lack both the c and e antigens, or units that lack only the c antigen.

Clinical implications
The f antigen can cause hemolytic disease of the newborn and transfusion reactions.

Rare
Antibodies against compound antigens are rarely described, and are often masked by other Rh antibodies or antibodies against other blood group systems.

Question 30

Compound antigen: C and e are in cis position:

Answer 30

Rhi (Ce)

Question 31

Present on most C(+) and D(+) positive red cells

Answer 31

G antigen

Question 32

Contains igM abs; can be used on red cells coated with IgG Ab; cannot be used on Weak D testing

Answer 32

Saline based Rh Antigen typing

Question 33

With added bovine albumin; short incubation time; can do Weak D test; contains IgG only

Answer 33

High-Protein based

Question 34

Contains modified IgG; low protein-based; replaced saline-reactive reagent:

Answer 34

Chemically-based

Question 35

Derived from a single clone of plasma cell; blend of both IgM/IgG; higher specificity:

Answer 35

Monoclonal antibody

Question 36

Rh null syndrome type; mutation in RhAG gene

Answer 36

Regular type Rh null syndrome

Question 37

Rh null syndrome type; mutation in RhCE gene/deletion in Rh gene

Answer 37

Amorphic type Rh null syndrome

Question 38

Antic will agglutinate with which red cells?

a. R1 Rz
b. r’ ry
c. Rz r’
d. Ro r’’

Answer 38

d. Ro r’’

Question 39

Anti-hr’’ will react in which of the red cells?

a. R2 ry
b. R2 r’’
c. R2 R2
d. R1 r’

Answer 39

d. R1 r’