4 Flashcards
(67 cards)
What is the MNS Blood Group System ISBT number?
002
When was the MNS Blood Group System discovered?
1927
What is the significance of the MNS Blood Group System?
It produces naturally occurring antibodies.
How many antigens are in the MNS Blood Group System?
More than 46 antigens.
Which antigens are commonly encountered in clinical settings?
M/N and S/s.
Where are MNS blood group antigens expressed?
Only on red blood cells (RBC).
How many M/N and S/s epitopes are present per RBC?
Approximately 1 million M/N and 170-250 thousand S/s.
What is the common phenotype for MNS blood group?
M+N+ and S-s+U+.
What are M and N antigens associated with?
Glycophorin A.
What destroys M and N antigens?
Ficin, papain, bromelin.
What is the amino acid difference between M and N?
M has serine and glycine; N has leucine and glutamic acid.
What are S and s antigens associated with?
Glycophorin B.
How many amino acids are in S and s antigens?
72 amino acids.
What is the amino acid difference between S and s?
S has methionine; s has threonine.
What type of antibodies are Anti-M and Anti-N?
Naturally occurring antibodies of IgM isotype.
How are Anti-M and Anti-N usually detected?
As room temperature saline agglutinins.
What can destroy Anti-M and Anti-N antibodies?
Proteolytic enzymes and neuraminidase.
What enhances the reactivity of Anti-M and Anti-N?
Acidification of serum to pH 6.5 and use of an albumin diluent.
What is the clinical significance of Anti-M and Anti-N?
Clinically insignificant as long as it does not react at 37°C.
What can Anti-N be used for?
Paternity testing.
What is Autoanti-N?
An autoantibody reported in hemodialysis patients.
What causes Autoanti-N?
Formaldehyde reacting with terminal leucine on N and ‘N’ antigens.
What is Alloanti-N?
A potent hemolysin observed in GYPB deficient patients.
What are the clinical implications of Anti-S, Anti-s, and Anti-U?
Always clinically significant; causes HTR and HDFN.