OTHER BLOOD GROUPS P2 Flashcards
found in glycophorin A (GPA) (major RBC sialic acid- rich glycoprotein)
M & N Antigens
(M & N Antigens)
antithetical and differ in their amino acid residues at positions 1 and 5
___: serine at position 1
___: glycine at position 5
M ; N
(M & N Antigens)
antigens are well developed at birth
yes
(M & N Antigens)
easily destroyed by _____, ____, ___ and by the less common enzymes ______ and _____
ficin, papain, and bromelin ; trypsin and pronase
also destroyed by ZZAP (combination of DTT and papain or ficin) BUT not affected by DTT alone,
2-aminoethyliso-thiouronium bromide (AET), α-chymotrypsin, chloroquine, or glycineacid EDTA
treatment.
(M & N Antigens)
M and N antibodies are _________
heterogeneous
found in glycophorin B (GPB)
differentiated by the amino acid at position 29
S & s Antigens
________ defines S, whereas ______ defines s
Methionine ; threonine
S and s also are well developed at birth.
yes
(S & s Antigens)
easily degraded by _____
enzymes
(S & s Antigens)
destroyed by ____, ______. ______, ______, and _______ ( amount of degradation may depend on the strength of the enzyme solution, the length of treatment, and the enzyme-to-cell ratio)
Ficin, papain, bromelin, pronase, and α-chymotrypsin
(S & s Antigens)
_________ by Trypsin , DTT, AET, chloroquine, or glycine-acid EDTA treatment
NOT destroyed
____: associates with protein band 3, which affects the expression of the antigen Wr(b) of the Diego blood
group system (located on protein band 3)
GPA
_____: associated with the Rh protein and Rh-associated glycoprotein complex as evidenced by the greatly
reduced S and s expression on Rhnull RBCs.
GPB
-naturally occurring saline agglutinins that react below 37°C
- 50% to 80% are IgG or have an IgG component
Anti- M
Anti- M do not bind _________ & do not react with ___________
complement ; enzyme-treated RBC
more common in children (especially patients with bacterial infections)
Anti- M
(Anti- M) Exhibits dosage: anti-M may react better with ______ RBCs (genotype MM) than with ______ RBCs
(genotype MN).
M+N– ; M+N+
(Anti- M)
Antibody reactivity can be enhanced by increasing the ________ or ________, or both, by decreasing incubation temperature or by adding a potentiating medium.
serum-to-cell ratio or incubation time
(Anti- M)
pH-dependent, reacting best at pH _____
6.5.
Anti-M does not react at ____ it is not clinically significant for transfusion
37°C,
- Anti-M rarely causes ____, decreased red blood cell survival, or ____
HTRs ; HDFN
(Anti- M)
Some: react only with _____ exposed to glucose solutions
RBCs
made by individuals whose RBCs type M+N– and S+ or s+
Anti- N
(Anti- N)
- cold-reactive IgM or IgG saline agglutinin
YES
not clinically significant unless it reacts at 37°C. (does not bind complement or react with enzyme-
treated RBCs.)
Anti- N
(Anti-N)
reacting better with _______ RBCs than with _______ RBCs
M–N+ (NN) ; M+N+ (MN)
Anti-N is seen in rare cases of ______
mild HDFN
less common than anti-M.
Anti- N
Also seen in renal patients who were dialyzed on equipment sterilized with formaldehyde.
Anti-N
(Anti-N)
Dialysis-associated anti-N reacts with any _______ RBCs treated with ________ (called anti-Nf )
anti-Nf does not react at ____, it is clinically insignificant for transfusion
N+ or N– ; formaldehyde ; 37°C
IgG, reactive at 37°C and the antiglobulin phase of testing
Anti- S & Anti- s
(Anti- S & Anti- s)
optimal reactivity between _____ and ______ by saline indirect antiglobulin test.
10°C and 22°C
may or may not react with enzyme-treated RBCs, depending on the extent of treatment and the
efficiency of the enzyme
Anti- S & Anti- s
seen less often than anti-M
Anti- S & Anti- s
(Anti- S & Anti- s)
clinically significant:
may bind _______
seen in severe HTRs with ______
also caused _____
complement ; hemoglobinuria ; HDFN
RBCs of three rare phenotypes lack GPA or GPB or both GPA and GPB; consequently, they lack all _______
MNS antigens
3 MNS PHENOTYPES
- U- Phenotype
- En(a-) Phenotype
- M(k) Phenotype
- located on GPB very close to the RBC membrane between amino acids 33 and 39
- have type S–s–U–
- can make anti-U in response to transfusion or pregnancy
U- Phenotype
found on RBCs of all individuals except about 1% of African Americans (and 1% to35% of
Africans) who lack GPB because of a partial or complete deletion of GYPB
U antigen
IgG ; reported to cause severe and fatal HTRs and HDFN.
Anti-U
altered GPB that does not express S or s.
U variant (Uvar):
RBCs, although weakly, by adsorption and elution
Anti-U react with apparent U–
1969, they described an antibody to the same high prevalence antigen, called Ena (for envelope)
Darnborough and coworkers and Furuhjelm and colleagues
1969: Darnborough and coworkers and Furuhjelm and colleagues described an antibody to the same high prevalence antigen, called Ena (for envelope)
En(a–) Phenotype
En(a–) individuals appeared to be
M–N–
produce anti-Ena
En(a–) Phenotype
En(a–) Phenotype results from homozygosity for a rare gene deletion at the _______
Cause: no ____ is produced, but ____ is not affected
GYPA locus ; GPA ; GPB
En(a–) Phenotype caused severe _____ and ______
HTRs and HDFN.
1964; they Named a rare silent gene M(k)
Metaxas and Metaxas-Buhler
single, near-complete deletion of both GYPA and GYPB
M(k) Phenotype
null phenotype in the MNS system
MkMk genotype
MkMk genotype is associated with decreased ________ content
but increased ________ of RBC membrane band 3.
RBC sialic acid ; glycosylation
- Autoantibodies to U and Ena: ________
- associated with warm-type __________
more common ; autoimmune hemolytic anemia
(Disease Associations in MNS)
- ______ may serve as the receptor by which certain pyelonephritogenic strains of E. coli gain entry to
the urinary tract - ___________ appears to use alternative receptors, including GPA and GPB for cell invasion
GPA(M) ; Plasmodium falciparum
ano na next group teh
The Kell (006) and Kx (019) Systems
- consists of 36 high-prevalence and low-prevalence antigens
- first blood group system discovered after the introduction of antiglobulin testing
Kell (006) & Kx (019) System
1946 ;
Anti-K was identified in the serum of ________
________ was described
Mrs. Kelleher ; anti-k
high-prevalence antithetical partner to K, was described
_____: was describe in 1957
Anti-K ; Kpa
Kpa was describe
discovery of the null phenotype designated Ko
1957
Kpb was describe
1958
Other antigens: ____ (described in 1958) and ____ (described in 1963)
Jsa ; Jsb
Kell blood group antigens are found only on _____
RBCs
K antigen can be detected on fetal RBCs as early as ______ ; well developed at birth
k antigen has been detected at _______
10 weeks ; 7 weeks
(Kell (006) & Kx (019) System)
- not denatured by the routine blood bank enzymes (______ & ______)
- destroyed by _______ & ________ (used in combination)
ficin & papain ; trypsin & chymotrypsin
(Kell (006) & Kx (019) System)
- Thiol-reducing agents, such as ___________, __________, ______, and ______ (which contains DTT in addition to enzyme), destroy Kell antigens but not Kx.
- _________ (an IgG-removal agent) also destroys Kell antigens.
100 to 200 mM DTT ; 2-mercaptoethanol (2-ME) ; AET ; ZZAP ; Glycine-acid EDTA
- K is rated ______ only to D in immunogenicity
second ; (ABO> D> K)
Anti-K appear to be induced by ________ and ________
pregnancy and transfusion
Alleles ____ and _____ are low-prevalence mutations of their high-prevalence partner Kpb
Kpa and Kpc
Kpa antigen found in about ___ of whites.
2%
associated with suppression of other Kell antigens on the same molecule, including k and Jsb.
Kpa gene
result from a reduced amount of the Kell glycoprotein inserted in the RBC membrane.
Kpa gene
rarer Kpa, Kpb, and Kpc antigen
Kpc antigen
_______, antithetical to the high-prevalence antigen Jsb
Jsa antigen
The prevalence of Jsa in ______ is almost 10 times greater than the prevalence of the K antigen in blacks.
blacks
Jsa and Jsb were linked to the _________ when it was discovered that Ko RBCs were Js(a–b–).
Kell system
most common antibody seen in the blood bank
Anti-K
Anti-K is:
- usually ___ and reactive in the ______ phase
- usually made in response to antigen exposure through ________ and ________
IgG ; antiglobulin ; pregnancy and transfusion
________________ examples of anti-K are rare and have been associated with bacterial infections.
Naturally occurring IgM
studied an IgM anti-K in an untransfused 20-day-old infant with an E. coli infection whose mother did not
make anti-K.
Marsh and colleagues
(IgM anti-K)
- react poorly in methods incorporating low-ionic media, such as ______, and in some automated systems.
- most reliable method of detection is the ____________
- Increase reactivity by _________, _____
- seen in severe _______.
- associated with severe ______.
- Fetal anemia in anti-K HDFN is associated with suppression of __________ due to destruction of erythroid precursor cells.
- LISS
- indirect antiglobulin test.
- potentiating medium, PEG
- HTRs
- HDFN
- erythropoiesis
(Antibodies to Kpa, Jsa, and Other Low-Prevalence Kell Antigens)
- _____ because so few people are exposed to these antigens.
- routine antibody detection RBCs do not carry ____________, the antibodies are most often detected through unexpected incompatible crossmatches or cases of HDFN.
rare ; low-prevalence antigens
(Antibodies to Kpa, Jsa, and Other Low-Prevalence Kell Antigens)
- The serologic characteristics and clinical significance of these antibodies parallel anti-K.
- The original anti-Kpa was naturally occurring, but most antibodies result from _______ or _______
transfusion or pregnancy.transfusion or pregnancy.
(Antibodies to k, Kpb, Jsb, and Other High-Prevalence Kell Antigens)
- rare because so few people ____ these antigens.
- They also _____ anti-K in serologic characteristics and clinical significance.
lack ; parallel
(Antibodies to k, Kpb, Jsb, and Other High-Prevalence Kell Antigens)
- ___________ are easy to detect but difficult to work with because most blood banks do not have the antigen-negative panel cells needed to exclude other alloantibodies
- Testing an unidentified high-prevalence antibody against _______ or _______-treated RBCs is a helpful
technique
High-prevalence antibodies ; DTT- or AET
(Antibodies to k, Kpb, Jsb, and Other High-Prevalence Kell Antigens)
- Caution is needed before assigning Kell system specificity until antigen-negative RBCs are tested because DTT also denatures JMH and high-prevalence antigens in the LW, Lutheran, Dombrock,
Cromer, and Knops systems. - Finding compatible units for transfusion can be difficult; siblings and rare-donor inventories are the
most likely sources.
yes
located on chromosome 7 at position 7q33
KEL gene
(KEL gene)
- Several different mutations have been found that result in the rare null phenotype ____
-People who tested _____ for two low-prevalence Kell antigens had always been found to carry the
encoding alleles on opposite chromosomes.
Ko ; positive
In 2009, report, two unrelated individuals with very weak K antigens were found to be heterozygous for _______ and ________
KKpa and kKpb
- encodes the Kx antigen
- independent of KEL
- located on the short arm of the X chromosome at position Xp21.
gene XK
present on all RBCs except those of the rare McLeod phenotype
Kx
have increased Kx antigen.
Ko and Kmod phenotype:
When Kell antigens are denatured with AET or DTT, the expression of Kx _______
increases
(Ko Phenotype & Anti-Ku)
_____ RBCs lack expression of all Kell antigens.
- no membrane abnormality and survive normally in circulation.
- phenotype is rare
ko
(Ko Phenotype & Anti-Ku)
_______: single specificity and cannot be separated into components.
- caused both HDFN and HTRs.
Anti-Ku
- described a young male medical student who initially appeared to be Kell null but who demonstrated weak
expression of k, Kpb, and Jsb detectable by adsorption-elution methods
Named after the student
1961: Allen and coworkers
- very rare. All are male, inheritance is X-linked
- RBCs lack Kx and another high prevalence antigen, Km, and have marked depressionof all other Kell antigens.
McLeod Phenotype & Syndrome
(McLeod Phenotype & Syndrome)
- __________ (having irregular shapes and protrusions) with decreased _______ and reduced in vivo
______
acanthocytic ; deformability ; survival
(McLeod Phenotype & Syndrome)
have a variety of muscle and nerve disorders that, together with the serologic and hematologic picture, are
collectively known as the __________
McLeod syndrome
(McLeod Phenotype & Syndrome)
develop a slow, progressive form of muscular _______ between ages 40 and 50 years and _________
(leading to cardiomyopathy)
dystrophy ; cardiomegaly
