UNCOMMON BLOOD GROUPS P1 Flashcards by Sharmaine Madjid

Composed of 22 antigens: three sets of high and low pairs of antithetical
antigens- Dia/Dib, Wra/Wrb, and Wu/Disk – and 16 low-prevalence antigens.

The Diego (010) System

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The Diego (010) System was named after the first antibody maker in a __________ during an investigation of _____

Venezuelan family ; HDFN.

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The Diego antigens are carried on _______ (RBC anion exchanger (AE1) or solute carrier family-4 anion exchanger, member 1 (SLC4A1)), a major integral RBC membrane glycoprotein with about 1 million copies per RBC.

band 3

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The protein crosses the membrane multiple times, and both the amino- and carboxyl-terminal domains are in the cytoplasm.

The Diego (010) System

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A large N-glycan on the fourth external loop carries over half the RBC A,
B, H, and I blood group Antigens.

The Diego (010) System

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The Diego (010) System Reported in 1955, ______ had caused HDFN in a Venezuelan baby.

______ was described 2 years later.

anti-Dia ; Anti-Dib

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______ is rare in most populations but is polymorphic in people of Mongoloid ancestry.

Dia

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In South American Indians, the prevalence of Dia can be as high as _____

54%

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____ is also present in the North and Central American native populations but is surprisingly rare in Canada and among the Alaskan Inuit.

Dia

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The prevalence of Dib is generally greater than 99% but is ____ in Native Americans.

96%

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The Dia/Dib polymorphism is located on the last (seventh) __________ of the protein.

extracellular loop

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___, a low-prevalence antigen, and the antithetical, high-prevalence ____ are
associated with an amino acid substitution on the fourth external loop.

Wra ; Wrb

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Expression of Wrb requires the interaction of band and normal GPA of the MNS blood group system. GPA-deficient RBCs are ______

Wr(a-b-).

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_________ are expressed on RBCs of newborns.

Diego Antigens

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the antigens are resistent to treatment with ficin and papain, DTT, and glycine-
acid EDTA, with exception of Bpa, which is sensitive to papain.

DIEGO ANTIGENS

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Diego system antibodies are sometimes ____, but are usually ____, reactive in the antiglobulin phase of testing.

IgM ; IgG

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Anti-Dia and Anti-Dib = Hemolytic Transfusion Reactions and HDFN

YES

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_______ is a relatively common antibody in donors and patients; some are directly agglutinating, but most require the antiglobulin phase of testing to be detected.

anti-Wra

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anti-Wra =

severe HTRs

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________ in individuals with Wr(a-b-) RBCs have been described,
so information about clinical significance is insufficient.

Alloanti-Wrb

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Autoanti-Wrb is relatively common in the serum of patients with ________

warm autoimmune hemolytic anemia.

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Which was named in 1956 for the first antibody maker and used the
last letter “t” in the patient’s last name, which was Cartwright.

The Yt (011) System

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____ is the high-prevalence antigen in all populations;

Yta

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_____ is the low-prevalence antigen found in about 8% of whites and 21% to 26% of Israelis, but is not found in Japanese.

Ytb

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Three phenotypes are observed in Yt System

The common Yt(a+b-) and Yt(a+b+) and the rare Yt(a-b+).

The Yt antigens are ______ and present an amino acid substitution on the glycosylphosphatidylinositol (GPI)- linked RBC glycoprotein acetylcholinesterase (AChE).

antithetical

______ is an important enzyme participating in neurotransmission, but the function of RBC- bound AChE is not known. Chromosome 7

AChE

Yt antigens are variably sensitive to _____ and _____, are sensititive to ____, and are resistant to ________ treatment.

ficin and papain ; DTT ; glycine-acid EDTA

the antigens are developed at birth but are expressed weaker on cord RBCs than on adult RBCs and are absent from RBCs of people with _________________

paroxysmal nocturnal hemoglobinuria (PNH) III.

Anti-Yta and Anti-Ytb are ____ and are stimulated by _______ or ________

IgG ; pregnancy or transfusion.

_______ is not an uncommon antibody, so it appears that Yta is reasonably immunogenic.

Anti-Yta

____ appears to be a poor immunogen, as the antibody is rare.

Ytb

Yt antibodies have not caused ______

HDFN

______________ may be helpful in determining clinical significance of anti-Yta.

Monocyte phagocytosis (MMA)

_____ was discovered in 1962 in the serum of a multiply transfused man.

anti-Xga

the antibody detected an antigen with a higher prevalence in females than in males.

The Xg(012) System

antigen Xga expression was controlled by an _______

X-linked gene

was named after the ______ and g for “_______” where the patient was treated.

X chromosome ; Grand Rapids

there are two antigens in Xg system: _____ and _____

Xga and CD99.

the gene XG encoding Xga is located on the X chromosome at _______

Xp22.32

the gene responsible CD99, MIC2, is located on the X chromosome at ______ and on the Y chromosome ______

Xp22.2 ; Yp11

_____ became part of the Xg system because the MIC2 and XG genes are adjacent and homologous and two CD99- Japanese individuals were found with ______

CD99 ; anti-CD99

* Xga has a phenotypic relationship to Cd99: - all Xg(a+) individuals have a ____ expression of CD99 on their RBCs, - all Xg(a- ) females have _____ expression of CD99; however, 68% of Xg(a-) males have a expression and 32% have low expression of CD99.

high ; low

* The prevalence of Xga is ____ in males and ___ in females. - because male have only 1 X chromosome, Xg(a+) males are hemizygotes. - females, having 2 X chromosomes, can be homozygote or heterozygotes.

66% ; 89%

Weak expression of Xga is seen on RBCs from some adult ____, but weak expression on RBCs from adult males is _____

females ; rare

The antigen is sensitive to ____ and _____ but resistant to _____ treatment.

ficin and papain ; DTT

Xg Antibodies: * Anti-Xga is usually _____; * Some examples are ________ * Anti-Xga has not been implicated in _____ or as a cause of _____.

IgG; ; naturally occurring. ; HDFN or HTRs

* Named after the first antibody maker. * In 1962, high prevalence antigen was named Sm; 1 year later, a new low prevalence antigen, Bua, was found. After it was confirmed that these two antigens were antithetical, the Scianna blood group was established in 1974, and the two antigens were renamed Sc1 and Sc2, respectively. * The prevalence of Sc2 in Northern Europeans is 1% but is higher in the Mennonite population.

The Scianna(013) System

The product of the gene is a protein called _______________ which is an RBC adhesion protein.

erythroid membrane-associated protein (ERMAP),

The Scianna(013) System Antigen * In 1980, an individual in the Marshall Islands in the South Pacific was found with the ______ * The very rare Sc:-1,-2,-3 phenotype is the ________ * The Sc gene ERMAP is located on chromosome 1 at position ______

Sc;-1,-2. ; Scianna null type ; 1p34.2.

The low-prevalence antigen Rd became ____

Sc4.

_______, ______, and ______ are all high-prevalence.

Sc5 (STAR), Sc6 (SCER), and Sc7 (SCAN)

The Scianna antigens are resistant to _____ and _______

ficin and papain.

The antigen are also resistant to ________. except for Sc2, which has variable reactivity after DDT-treatment.

DTT treatment

The Scianna antigens are expressed on _______

cord RBCs

(Scianna Antibodies) * Alloantibodies to Scianna antigens are _____, and little is known about their clinical significance.

rare

(Scianna Antibodies) * They are usually ____ and reactive in the ________ phase of testing.

IgG ; antiglobulin

(Scianna Antibodies) * None have been reported to cause a severe ____

HTR

(Scianna Antibodies) * Only mild HDFN has been reported, except for one severe case for anti-Rd, for which the baby required _________

exchange transfusion.

(Scianna Antibodies) * autoantibodies to ____ and ____ have been reported.

Sc1 and Sc3

Was named for the first antibody maker, Mrs. Dombrock (anti-Doa), found in 1965.

The Dombrock (014) System

______, which recognizes the antithetical antigen, was identified in 1973.

Anti-Dob

The prevalence of the three resulting phenotypes, Do(a+b-), Do(a+b+), and Do(a-b+), varies in different populations. In whites, they are _____, _____, and ____ respectively.

18%, 49%, and 33%,

The high-prevalence antigens ____ and ____ were both described in 1967.

Gya and Hy

RBCs from whites who are Gy(a-) were found to be ____, but Hy- RBCs from blacks were weakly _____.

Hy- ; Gy(a+)

The high-prevalence antigen Joa was described in 1972, and the phenotypic relationship to Gya and Hy was later shown: Gy(a-) RBCs or Hy- RBCs were also _____

Jo(a-).

In 1995, it was reported that Gy(a-) RBCs were also _____

Do(a-b-).

The Gy(a-) phenotype is the _______

Dombrock null

The Dombrock system currently has five additional high-prevalence antigens:

DOYA, DOMR, DOLG, DOLC, AND DODE.

The Dombrock antigens are carried on a _________ attached to the RBC membrane by a GPI anchor.

mono-ADP-ribosyltransferase 4 (ART4)

The gene ART4 encoding the Dombrock glycoprotein is located on _________ at position 12p13-p12.

chromosome 12

The Dombrock antigens are resistant to ficin, papain, and glycine-acid EDTA and are sensitive to 0.2 M DTT treatment.

yes

The antigens are present on cord RBCs, but are absent from ______ RBCs

PNH III

The ____ and _____ antigens are poor immunogens and antibodies are rarely found as single specificities

Doa and Dob

_____, is highly immunogenic.

Gya

_____ and _____ have caused delayed HTRs but no Clinical HDFN.

Anti-Doa and Anti-Dob

The ________ are usually IgG, reacting optimally with enzyme-treated RBCs. These antibodies are usually weakly reactive and disappear.

Dombrock antibodies

* Consists of four antigens. * The system was named in 1967 for the first antibody maker; it should have been named “Calton”.

The Colton (015) System

The high- and low-prevalence antithetical antigens are _____ and _____

Coa and Cob

The third antigen, ____, is present on all RBCs except those of the very rare Co(a–b–) phenotype.

Co3

____, a high-prevalence antigen, has been identified on RBCs from two individuals with the Co(a–b–) phenotype.

Co4

The Colton antigens are carried on an integral membrane protein, ________

aquaporin 1 (AQP1).

The gene AQP1 is located on _______ at position 7p14

chromosome 7

The ___________ are expressed on RBCs of newborns and are resistant to treatment with ficin and papain, chloroquine, and DTT

Colton antigens

usually IgG and are enhanced with enzyme treated RBCs.

(Colton antibodies)

(Colton antibodies) ______ is often seen as a single specificity and has been reported to cause HTRs and HDFN.

Anti-Coa

(Colton antibodies) ______ appears more often with other specificities but has also caused HTRs and mild HDFN.

Anti-Cob

(Colton antibodies) _____, which reacts with all Co(a+) and Co(b+) RBCs, has been reported to cause mild HTR and severe HDFN.

Anti-Co3

* Had its origins along with the discovery of the D antigen of the Rh blood group system. * In 1940, Landsteiner and Wiener reported that an antibody produced in rabbits (and later, guinea pigs) after injection with RBCs of rhesus monkeys reacted with 85% of human RBCs.

The Landsteiner-Wiener (016) System

* The two antibodies were later shown to be different in several studies; ⚬ in the 1960s, the human anti-Rh was renamed ____ (but called anti-Rho by some workers), and the rabbit anti-Rh was called ______ in honor of Landsteiner and Wiener.

anti-D ; anti-LW

There are three LW antigens: The first two, _____ and ____, are common, high-prevalence anti?gens, and ___ is of low prevalence

LWa, LWab, and LWb. LWa and LWab ; LWb

____ was originally defined by the antibody made by an individual with an in?herited LW(a–b–) phenotype.

LWab

The ISBT has used ____, ____., and _____ as the antigen numbers for LWa, LWab, and LWb, respectively.

LW5, LW6, and LW7

The null phenotype is ________; in one individual who made anti-LWab (Mrs. Big), this phenotype resulted from a 10-base pair deletion in exon 1 of an LWa gene, which introduced a premature stop codon.

LW(a–b–)

phenotypic relationship between the D antigen and anti-LW.

yes

Anti-LW usually reacts strongly with ____ RBCs, weakly with ___ RBCs from adults, and not at all with ____ RBCs.

D+ ; D– ; Rhnull

Distinguishing anti-LW from anti-D is most easily accomplished by testing DTT-treated D+ RBCs: ⚬ the D antigen is not denatured by ____, so anti-D would still be detected; ⚬ however, LW antigen is destroyed by ____, so anti-LW would no longer react. LW antigens are resistant to treatment of RBCs with ____ and _____

DTT ; DTT ; enzymes and glycineacid EDTA.

The structure that carries the LW antigens is a glycoprotein known as ____________-

intracellular adhesion molecule 4 (ICAM-4).

The LW glycoprotein is part of the band 3/Rh macrocomplex;15 Rhnull RBCs lack the LW glycoprotein. * The LW gene ICAM4 is located on chromosome __ at position 19p13.2

LW antigens may be depressed during pregnancy and in some diseases, such as _______ and _____ Autoanti-LW made by these patients can appear to be an alloantibody; as the antigen strength returns, the antibody diminishes.

lymphoma and leukemia.

* Autoanti-LW is also common in serum from patients with ________.

warm autoimmune hemolytic anemia.

No anti-LW has been shown to cause serious HDFN or transfusion reactions. Many patients with anti-LW have successfully been transfused with D– RBCs.

yes

UNCOMMON BLOOD GROUPS P1 Flashcards

(103 cards)