IgG Blood Group Systems Flashcards
What are the 5 main IgG blood group systems?
Rh Kell Duffy Kidd SsU (of MNSs)
List 7 characteristics of IgG antibodies
Red cell or immune stimulated small in size - no direct agglutination warm reactive - 37C Most IgGs do NOT bind complement Require AHG to visualize in vitro can cross the placenta and cause HDNF are clinically significant because HTR, usually delayed
What are the 6 Kell antigens and what is the most common phenotype?
K and k
Kpa and Kpb
Jsa and Jsb
K-k+, Kp(a-b+), Js(a-b+)
What percentage of the population is K+?
9%
Which Kell antigen is more common is blacks?
Jsa, 20% compared to less than .1% in whites
What are some characteristics of K?
K ags are very immunogenic
Kell antigens are destroyed by DTT, AET, and ZZAP
Ags are unaffected by enzymes
What is the McLeod phenotype?
K genes inherited but no K precursor so there is a weakened expression of all K ags
Associated with Chronic Granulamatous Disease
What are some characteristics of Kell antibodies?
Anti-K is most common antibody seen since K is 3rd most immunogenic
antibodies to other antigens rarely seen since they are so rare
clinically significant HTR and HDN. must be honored in XM
What are the Duffy Ags and phenotypes?
Fya, Fyb, Fy
Fy(a+b-)
Fy(a+b+)
Fy(a-b+)
Fy(a-b-) -> FyFy
Duffy Antigen Characteristics
Fy gene is common is AA (68%) and gives rise to Fy(a-b-) which is linked to resistance to malaria
destroyed by enzymes
not very immunogenic
strongest disparity among races
Duffy antibodies
IgG so react best at AHG
anti-Fya is more common than b
dosage is observed
CLINICALLY SIGNIFICANT - HTR HDNF
Kidd blood group antigens
Jka Jkb
fully developed at birth - HDNF
Jk(a-b-) found in polynesians
poor immunogens
Kidd antibodies
NOTORIOUS for causing HTR
Ab titer drops quickly in vivo and vitro
seen with other antibodies
only super responders make Kidd abs because the are poor immunogens
Abs might be hemolytic; require fresh cā source (serum)
SsU antigens
S and s are allelic
U is a universal antigen but AA more likely to be S-s-U-
inherited with MN as a packet
SsU antibodies
may cause HDN HTR
anti-U found only in S-s-U- people
Additional Blood Groups
Lutheran antibodies usually demonstrate MF agglutination
most antithetical pairs consist of one high incidence and one low incidence ag
high incidence antibodies; look at siblings, rare donor file or self for compatible blood
What blood group is related to the HLA system
Bga and Bgb
What blood group is sex-linked
Xga
What low frequency ag is found mostly in south american indians?
Dia
What high frequency antigen is found in urine and whose antibody is mixed field and refractile?
Sda
Which antigens are destroyed by enzymes
duffy, MNSs
Which antigens are enhanced by enzymes
ABO, Rh, Ii, P, Lewis, Kidd
Which blood group is unaffected by enzymes but destroyed by chemicals?
Kell
How does enzyme treatment affect RBC antigens
They remove the sialic acid residues and denature glycoproteins. So some ags are destroyed while others are exposed.
Which Abs can be hemolytic?
ABO, Lewis, Kidd
