KIDD,Duffy,MNS Flashcards
What Kidd phenotype is twice as common in blacks than white?
Jk(a+b-)
The Jk(a-b-) phenotype is very rare, what population is it primarily encounted in? (2)
- Finns
- Polynesians
What is the function of the Kidd protein?
Urea transport protein
Jk (a-b-) cells are resistant to what?
-Individuals with this phenotype have what kind of defect?
Hemolysis in 2M urea
-Mild urine concentrating defect
Kidd phenotype prevalence in Blacks (decreasing order).
- Jk(a+b-) - 60%
- Jk(a+b+) - 30%
- Jk(a-b+) - 10%
- Jk(a-b-) - rare
Kidd phenotype prevalence in Whites (decreasing order).
- Jk(a+b+) - 50%
- Jk(a+b-) - 30%
- Jk(a-b+) - 20%
- Jk(a-b-) - rare
What type of an antibodies are Kidd antibodies?
- Temp
- Class
- Acquisition
- Warm reacting
- IgG antibodies
- Acquired only through exposure
What are Kidd antibodies notoriously known for?
Difficult to detect
“tricky Kidd”
Why are Kidd antibodies difficult to detect?
- Display dosage and may only react with homozygous cells (may result in false-negative crossmatch)
- Tend to fall below the threshold for detection over time
*Historical Kidd Abs is reason enough to give Kidd antigen negative blood (CHECK BLOOD BANK RECORDS!)
Kidd antibodies most often only react at what phase?
AHG
Kidd antigens are _____ by enzymes.
Enhanced
What is the most common cause of delayed hemolytic transfusion reactions?
Kidd
Does Kidd cause hemolytic disease of newborn?
-Why?
Rarely
-Weakly expressed by fetus
What 2 antigens comprise the Duffy system?
Fya and Fyb
Duffy antigens are present on Duffy associated receptor for chemokines (DARC), which is a receptor for what?
Plasmodium vivax (malaria)
Which phenotype is more common:
-F(a-b+) or F(a+b-)
F(a+b-)
What is the Duffy phenotype that differs most between blacks and whites?
-Whats the explanantion?
Blacks - Fy(a-b-) is common (68%); Whites - Rare
-confers resistence to Plasmodium vivax
Because of differeing mechanisms of Duffy negativity in whites and blacks, what is true about the development of Fy antibodies?
Most Fy(a-b-) Blacks do NOT form anti-Fy Ab -Fy(a-b-) Whites do for an anti-Fy Ab
What type of an antibodies are Duffy antibodies?
- Temp
- Class
- Acquisition
- Warm
- IgG
- Acquired through exposure
Duffy Antibodies (do or do not) show dosage effect.
Duffy antibodies show dosage
Duffy antigens are _______ by enzymes.
Destroyed
T/F: Duffy antibodies are capable of causing HTR and HDFN.
True
MNS antigens - Which genes display genetic linkage?
MN and SsU genes
MNS antigens - Most frequent haplotypes?
Ns and Ms
MNS antigens - M and N antigens are found on what?
Glycophorin A
What is are the phenotype prevalence of MNS antigens?
- M+N+ (50%)
- M+N- (25%)
- M-N+ (25%)
Where do the S, s, and U antigens reside?
Glycophorin B
S, s, and U frequencies?
-s and U - high prevalence (98%)
S antigen
-Whites (50%)
-Blacks (30%)
Anti-M antibodies:
- Temp
- Class
- Clinical Sig or Not
- Acquisition
MNS antibodies:
- Cold
- IgM
- NOT clinically significant
- Naturally occuring
Why are anti-N antibodies rare?
epitope on Glycophorin B has N like antigenicity
When are Anti-Nf antibodies formed?
Dialysis patients exposed to formaldehyde
-Induced formation of Nf antigen on RBCs
Anti-S, s, U Antibodies:
- Temp
- Class
- Clinical sig?
- Acquisition
Anti-S, s, U Antibodies:
- Warm
- IgG
- Clinically Significant
- acquired following exposure
Do MNS antibodies display dosage?
Yes
M and N antigenicity is _______ by enzymes.
Destroyed
