MNSs, Kell, Duffy, and Kidd Blood Group Systems Flashcards
MNSs _______ are glycoproteins and glycophorins.
Antigens
MNSs antigens are sensitive to cleavage by _________; S and s vary in sensitivity.
Proteases
M and N antigens are on the external segment of __________ molecules, with around half a million copies per cells.
Transmembrane
If cells do not react with Anti-M, but do react with Anti-N, their phenotype is written M-N+, and the genotype is _____.
NN
Outline the characteristics of Anti-M.
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
Describe Anti-N.
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
True or false: neither Anti-M or Anti-N display dosage.
False
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 ____.
IgG
In inheritance, two sets of co-dominant alleles, MN, and Ss, are inherited at fairly closely-linked ______.
Loci
What genotype does M+N-S+s- have?
MS/MS
True or false? Crossing-over is never observed in MNSs inheritance.
False
Name the two antibodies associated with the Kell system.
Anti-K and Anti-k
Kell antigens include K, k (Cellano), Kpa, Kpb, Jsa, and Jsb, with about ___ antigens in total.
24
Write a note on the antigen aspect of the Kell blood group system.
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
Kell antibodies are mostly ______.
IgG
Write a note regarding the discovery and physiological characteristics of the Duffy blood group system.
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
Write a note regarding the discovery and physiological characteristics of the Duffy blood group system.
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
Describe the Kidd blood group system antibodies.
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
The three most common Kidd phenotypes are:
Jk(a+b-), Jk(a-b+), and Jk(a+b+). The null phenotype, Jk(a-b-), is rare
