Other Blood Groups

Question 1

What are the main antibodies in the ABO and Rh systems?

Answer 1

ABO= bench temperature IgM
Rh = 37-degree reactive IgG

Question 2

How are ABO IgM antibodies detected?

Answer 2

Detect presence of antibodies using RBCs expressing single ABO antigens (A1 and B cells)
Detected in the lab using RBCs expressing A, B & AB antigens in a defined saline solution
Patient Anti-A, Anti-B, and Anti-AB antibodies are IgM, so they bridge the gap between adjacent RBCs in saline

Question 3

How are IgG antibodies detected?

Answer 3

IgG antibodies from patients cannot bridge the gap between RBCs in saline. Need to use a two-step process
1. Sensitisation of RBCs (with patient IgG antibodies)
2. Agglutination of sensitised RBCs (with another antibody; anti-human globulin)

Question 4

What is the Kell blood group system?

Answer 4

The KEL gene encodes a glycoprotein. Two codominant alleles, K and k, which differ by a single amino acid.

Question 5

What are the Kell antigens?

Answer 5

There are 25 high and low-incidence antigens described. The two main ones are K and k.

Question 6

What are the Kell antibodies?

Answer 6

Anti-K and anti-k, IgG isotype, detection using AHG phase methods.

Question 7

What diseases are associated with Kell blood grouping?

Answer 7

Can cause severe haemolytic transfusion reactions
Can cause severe (fatal haemolytic disease of the foetus & newborn; HDFN)

Question 8

What is the Duffy blood group?

Answer 8

FY gene (encodes for glycoprotein)
2 codominant alleles (Fya, Fyb) differ by a single amino acid

Question 9

What are the Duffy antigens?

Answer 9

There are 6 antigens, including Duffy Null, Fya and Fyb

Question 10

What type of infections are related to the Duffy blood group?

Answer 10

The antigens provide resistance to malaria infections

Question 11

What are the Duffy antibodies?

Answer 11

Anti-Fya, anti-Fyb
IgG (immune)
Detection using AHG phase methods

Question 12

What diseases are associated with the Duffy blood group?

Answer 12

Can cause moderate, delayed haemolytic transfusion reactions, and can cause mild haemolytic disease of the foetus and newborn

Question 13

What are the genetics of the Kidd Blood Group?

Answer 13

The SLC14A1 gene encodes for Kidd antigens. Two codominant alleles that differ by a single amino acid.

Question 14

What are the antigens of the Kidd group?

Answer 14

Jka, Jkb and Jk3

Question 15

What are the Kiid antibodies?

Answer 15

Anti-Jka, anti-Jkb
IgG, some are IgM.
Detection using AHG phase methods

Question 16

What diseases are associated with the Kidd blood group?

Answer 16

Common cause of delayed haemolytic transfusion reactions. Can cause mild haemolytic disease of the foetus and newborn

Question 17

What are the genetics of the MNSs blood group?

Answer 17

GYPA and GYPB genes encode for MNSs antigens.
GYPA - two codominant alleles (M and N) differ by two amino acids
GYPB - two codominant alleles (S, s) differ by a single amino acid.

Question 18

What are the antigens of the MNSs blood group?

Answer 18

There are 43 antigens, M, N, S, and s are the most important

Question 19

What are the antibodies of the MNSs blood group?

Answer 19

Anti-M, anti-N are usually IgM
Anti-S and anti-s are usually IgG

Question 20

What diseases are associated with the MNSs blood group?

Answer 20

Uncommon cause of haemolytic transfusion reactions (anti-S and anti-s)
Uncommon but potentially severe or fatal cause of haemolytic disease of the foetus and newborn.

Question 21

What are the genetics of the Lewis Blood Group?

Answer 21

Three possible sets of genes: Lele, LeLe, lele. The gene codes for fucosyl transferase, which adds L-fucose to the precursor substance. Inherited along with the ABO and SE/se system.

Question 22

What are the Lewis Blood group antigens?

Answer 22

Lea and Leb, soluble antigens, are not made in red cells; they’re secreted and then absorbed into the cell.

Question 23

What are the Lewis blood group antibodies?

Answer 23

Anti-Lea, and anti-Leb

Question 24

What diseases are associated with the Lewis blood group system?

Answer 24

There are mostly clinically insignificant IgM’s which do not lead to disease. Does not cause haemolytic disease of the foetus and newborn

Question 25

What are the genetics of the Lutheran blood group?

Answer 25

BCAM gene Two codominant alleles

Question 26

What are the Lutheran antigens?

Answer 26

There are 19 antigens: Lua and Lub are the most important

Question 27

What are the Lutheran antibodies?

Answer 27

Anti-Lua is usually IgM anti-Lub is usually IgG

Question 28

What diseases are associated with the Lutheran blood group?

Answer 28

Anti-Lub can cause mild haemolytic transfusion reactions, occasionally haemolytic disease of the foetus and newborn

Question 29

How are the other blood groups tested?

Answer 29

Using a 3 cell panel. A “panel” of 3 RBC test reagents with known antigen expression are used to detect Rh and other blood groups The cells used are group O (2 x RhD pos, 1 RhD neg), so detection of ABO antibodies do not “mask” the detection of other groups

Question 30

What is immunogenicity?

Answer 30

Immunogenicity refers to the ability of an antigen to stimulate an immune response

Question 31

What is the Rhesus D immunogenicity?

Answer 31

50%

Question 32

What is the big K Kell immunogenicity?

Answer 32

5%

Question 33

What is the immunogenicity of Rhesus little c?

Answer 33

2.05%

Question 34

What is the Rhesus big E immunogenicity?

Answer 34

1.69%

Question 35

What is the little k Kell immunogenicity?

Answer 35

1.5%

Question 36

What is the Rhesus little e immunogenicity?

Answer 36

0.56%

Question 37

What is the immunogenicity of the Duffy Fya antigen?

Answer 37

0.23%

Question 38

What is the Rhesus big C immunogenicity?

Answer 38

0.11%

Question 39

What is the immunogenicity of the Kidd Jka antigen?

Answer 39

0.07%

Question 40

What is the immunogenicity of the MNSs big S antigen?

Answer 40

0.04%

Question 41

What is the immunogenicity of the Kidd Jkb antigen?

Answer 41

0.03%

Question 42

What is the immunogenicity of the MNSs little s antigen?

Answer 42

0.03%

Question 43

List the clinically significant antigens from most to least immunogenic.

Answer 43

Rhesus, Kell, Duffy, MNSs, P, Lewis, then Lutheran.

Question 44

Why is testing all this stuff important?

Answer 44

Medical scientists ensure that blood from a donor given to a recipient/patient is compatible (no adverse reactions) ABO and RhD blood groups of donor and recipient samples are determined to ensure ABO and RhD compatibility

Question 45

Why do patients still die from blood transfusions?

Answer 45

Unexpected or rare antibodies that are not detected in the laboratory can occur with patients with a history of multiple transfusions and/or pregnancies Unexpected reactions to transfusions in vivo, despite apparent in vitro compatibility Human error in the laboratory