MNSs, Kell, Duffy, and Kidd Blood Group Systems

Question 1

MNSs _______ are glycoproteins and glycophorins.

Answer 1

Antigens

Question 2

MNSs antigens are sensitive to cleavage by _________; S and s vary in sensitivity.

Answer 2

Proteases

Question 3

M and N antigens are on the external segment of __________ molecules, with around half a million copies per cells.

Answer 3

Transmembrane

Question 4

If cells do not react with Anti-M, but do react with Anti-N, their phenotype is written M-N+, and the genotype is _____.

Answer 4

NN

Question 5

Outline the characteristics of Anti-M.

Answer 5

Anti-M occurs frequently, agglutinates at RT (or below) in saline, does not bind complement, often naturally-occurring IgM, and sometimes IgG, and does not react with enzyme-treated cells. It has been implicated in HDN and haemolytic reactions

Question 6

Describe Anti-N.

Answer 6

Anti-N occurs rarely, is cold-reactive, does not activate complement, does not react with enzyme-treated cells, usually IgM, and is only clinically significant if it reacts at 37 degrees Celsius

Question 7

True or false: neither Anti-M or Anti-N display dosage.

Answer 7

False

Question 8

Anti-S and Anti-s are uncommon, and are more likely to be clinically significant; they usually occur after red cell stimulation, and are normally ____.

Answer 8

IgG

Question 9

In inheritance, two sets of co-dominant alleles, MN, and Ss, are inherited at fairly closely-linked ______.

Answer 9

Loci

Question 10

What genotype does M+N-S+s- have?

Answer 10

MS/MS

Question 11

True or false? Crossing-over is never observed in MNSs inheritance.

Answer 11

False

Question 12

Name the two antibodies associated with the Kell system.

Answer 12

Anti-K and Anti-k

Question 13

Kell antigens include K, k (Cellano), Kpa, Kpb, Jsa, and Jsb, with about ___ antigens in total.

Answer 13

24

Question 14

Write a note on the antigen aspect of the Kell blood group system.

Answer 14

Third most polymorphic antigens, after Rh and MNSs. Antigens are glycoproteins (with about 3,500 - 17,000 copies per cell). Most individuals will have the RBC phenotype K-k+. The null type, K0, was discovered in 1957. The McLeod phenotype, discovered in 1961, has weakened expression of Kell antigens, and there are structural abnormalities.
Enzyme activities, through endopeptidase, are at play with antigens

Question 15

Kell antibodies are mostly ______.

Answer 15

IgG

Question 16

Write a note regarding the discovery and physiological characteristics of the Duffy blood group system.

Answer 16

Discovered in 1950, as an antibody found in the serum of a multi-transfused haemophiliac, who was Anti-Fya-negative; the system was named after patient’s last name. Anti-Fyb was found a year later. At least six other antigens exist; they are glycoproteins, and chemokines. Fy(a-b-) phenotype is associated with resistance to severe malaria. Can be degraded by enzymes. Often seen in combination with other antibodies. Antigens were not overly immunogenic. Antibodies are infrequent, and are IgG, associated with HDN and reaction, bind complement, reactive in AGT, and capable of displaying dosage

Question 17

Write a note regarding the discovery and physiological characteristics of the Duffy blood group system.

Answer 17

Discovered in 1950, as an antibody found in the serum of a multi-transfused haemophiliac, who was Anti-Fya-negative; the system was named after patient’s last name. Anti-Fyb was found a year later. At least six other antigens exist; they are glycoproteins, and chemokines. Fy(a-b-) phenotype is associated with resistance to severe malaria. Can be degraded by enzymes. Often seen in combination with other antibodies. Antigens were not overly immunogenic. Antibodies are infrequent, and are IgG, associated with HDN and reaction, bind complement, reactive in AGT, and capable of displaying dosage

Question 18

Describe the Kidd blood group system antibodies.

Answer 18

Anti-Jka and Anti-Jkb are usually immune-mediated, generally IgG, detect dosage differences, bind complement, are enhances by enzyme treatment, and are implicated in HDN and HTR

Question 19

The three most common Kidd phenotypes are:

Answer 19

Jk(a+b-), Jk(a-b+), and Jk(a+b+). The null phenotype, Jk(a-b-), is rare