exam 2 - other blood group systems Flashcards
(T/F) antigens are part of a gene sequence that codes only for the structure of the antigen
false
some genes code for enzymes that form the ag
(T/F) transfusion recipients can get a matched ABO and Rh but are not likely to receive identical cells in other blood group system
true
_____ identifies a blood group /antigen in a blood group
alloantibody
which of the ff blood group system contains the least amount of polymorphism? (clarify this)
a. Lw
b. MNS
c. Rh
d. Kell
A
(T/F) DNA analysis can detect polymorphisms/ variants that can be classified into a blood group
false
MUST be defined by an alloantibody
(T/F) type 1 single pass antigens have an intracellular C-terminal structure
true
Type 2 single pass have intracellular N-terminal
which of the ff is not a carbohydrate-type blood group?
a. ABO
b. Lewis
c. P
d. duffy
D
which of the ff is false about Secretors?
a. FUT2 secretor gene produces fucosyltransferase like the H gene
b. Secretors have ABH substance in body secretions and in plasma
c. Se fucosyltransferase acts on Type 2 chains
d. onlly 20% of the population are non-secretors
C
acts on type 1 chains (soluble precursor)
which of the ff is the gene that codes for fucosyltransferase involved in the Lewis system?
a. FUT4
b. FUT3
c. FUT2
d. FUT1
B
FUT3 = Le FUT2 = Se
(T/F) Lewis antigen is formed in plasma and subsequently adsorbed onto RBCs
true
which of the ff is false about the Lewis system?
a. Le gene is linked to Se and H genes
b. Le gene codes for enzymes that form both Le(a) and Le(b) antigens
c. only the Le(b) antigen is adsorbed in RBCs
d. Le(b) is formed thru interactions of FUT3 and FUT2 genes
B
Le gene alone = Le(a)
Le gene + Se gene = Le(b)
(T/F) type 2 chains are found in cell surface membranes
true
which of the ff is a non secretor?
a. Le (a+b-)
b. Le (a-b-)
c. Le (a+b+)
d. Le (a-b+)
A
B can also be a non secretor (LeSe but Le gene may be mutated)
(T/F) an Le(a-b+) phenotype means that only Le(b) is present in both RBCs and in plasma
false
Le(a) can also present but is not as easily absorbed into RBCs so only Le(b) is detected
(T/F) the Le gene codes for an enzyme that forms the Le(b) antigen
true
(T/F) the Le(a+b-) phenotype is most common among whites, blacks and japanese
false
Le(a-b+) is most common,
Le(a+b-) is a non secretor (found in minority)
Lewis antibodies are:
a. IgG
b. IgM
B
cold reactive
which of the ff is not true about Lewis ab?
a. are only found in Le(a-b-) phenotype
b. anti-Le(a) may react and bind compl at 37C
c. are never IgG
d. Anti-Le(a) is stronger and more common that anti-Le(b)
C
some can be IgG
which of the ff is true about P blood group?
a. D-galactose is the immunodominant sugar
b. does not add L-fucose
c. P antigens are formed on type 1 chains
d. P1 antigen are found on other blood cells
C
formed in type 2 chains
which phenotype will most likely react with anti-P?
a. P1 only
b. P2 only
c. P1 and P2
d. p (null)
C
coz P1 has P1 and P precursor
P2 = P1 neg but still has P precursor
(T/F) the P2 phenotype reacts with Anti-P1 and not with Anti-P
false
coz P2 = P1 neg + P precursor
P2 reacts with anti-P only
which of the ff is not true?
a. Anti- PP1Pk is reactive over broad thermal range
b. P1k and P2k phenotypes are rare
c. anti-P1 is a rare, severe reacting ab
d. Anti-P1 is rarely IgG
C
it is a common benign ab
(T/F) ab directed againts P and Pk ag are associated w/ higher abortion rate in women with p or P1k or P2k phenotype
true
which of the ff is false?
a. both I and i ag are low incidence ag
b. the i ag is present mostly at birth or cord blood
c. i antigen is a branched precursor for ABH antigens
d. I and i are not antithetical
A
are high incidence
so Ab against them are rare
which of the ff is not true for Anti-I?
a. a common benign ab
b. is a cold agglutinin
c. is an auto ab
d. shows strong agglutination in cord RBCs but weaker rxn with adult RBC
D
the other way around
which of the ff is not true about the MNS system?
a. ag are carried on glycophorins GPA and GPB
b. ag are encoded by M or N and S or s genes
c. genes are inherited as a haplotype
d. ab rxn is enhanced with enzyme treated cells
D
ag are cleaved by enzymes
(T/F) the sialioglyprotein GPA is a pathogen receptor in E. coli and influenza infections and can give resistance to parasitic infections
true
(T/F) the enzyme cleavage site for the MNS antigens occur just above where the antigen detection site is located
false
cleavage site is below where they sit in the glycophorin, so they are removed w/ enzyme treatment
which MN phenotype is commonly seen in both whites and blacks?
a. M+N-
b. M+N+
c. M-N+
d. M-N-
B
which Ss phenotype is commonly seen in whites?
a. S+s–U+
b. S+s+U+
c. S–s+U+
d. S–s–U–
b and c
S+s+U+ = 44% S-s+U+ = 45%
which MNS ag are found on GPB?
a. M only
b. both M and N
c. S and s
d. M, N and Ss
C
which of the ff can cleave MNS ag from its glycophorin?
a. ficin and papain
b. trypsin and pronase
c. DTT and AET
d. chloroquine
A
(T/F) linkage disequilibrium is seen between S and s, and M and N antigens
true
which is the correct order of relative frequencies of MNS haplotypes that are seen in caucasians?
a. NS>MS>Ms>Ns
b. Ms>Ns>MS>NS
c. Ns>Ms>MS>NS
d. NS>MS>Ms>NS
C
which of the ff is false about Anti-M?
a. are a mixture of IgM and IgG
b. reacts at 37C
c. reaction is stronger with M+N-
d. reacts best at pH 6.5
B
reacts at
which of the ff is false about Anti-S and s?
a. are mostly IgM
b. unlikely reacts with enzyme treated RBcs
c. may cause HDNF
d. reacts at 37C
A
are mostly IgG
which of the ff is false about Anti-U?
a. are found in ppl of African ancestry
b. are usually IgM
c. production is stimulated by transfusion or pregnancy
d. may cause HDFN
B
are usually IgG
which of the ff phenotypes are more associated with people of African descent?
a. M+N-
b. S+s+U+
c. M-N+
d. S-s-U-
D
must know this!!!
M+N+, S-s-U-