UNCOMMON BLOOD GROUPS P2 Flashcards
Named after the first two antibody producers, Ch for Chido and Rg for Rodgers.
These two antibodies were described in 1967 and 1976.
The Chido/Rodgers (017) System
Serologically, they were both (The Chido/Rodgers (017) System) characterized as _______ because antigen strength on different samples of RBCs was variable.
NEBULOUS
It was also appreciated that both anti-Ch and anti-Rg could be neutralized by
_______
plasma
Ch and Rg antigens are not ______ to the RBC membrane.
Rather, they are on the _____ component of complement (C4), and are adsorbed onto RBCs from plasma
intrinsic ; fourth
C4 glycoprotein has two isoforms:
- C4B carries the Ch antigens
- C4A expresses Rg antigens.
The genes C4A and C4B at two closely linked loci located on chromosome __ at position 6p21.3 encode these isoforms.
6
The Chido/Rodgers system consists of nine antigens: ___ to ___, ____ and ___ are all high prevalence; ___ has a prevalence of about 15%.
Ch1 to Ch6, Rg1, and Rg2 ; WH
___ is present in 96% to 98% of most populations.
___ is present in 97% to 98% of most populations.
The antigens are destroyed by ficin and papain but are resistant to treatment with DTT and glycine-acid EDTA.
Ch; Rg
Anti-Ch and anti-Rg are usually ___ and react weakly, often to moderate or high titration endpoints.
IgG
Neutralization of anti-Ch and anti-Rg with pooled plasma is often used as part of the identification of these antibodies in a patient’s serum. ____ and ______ are clinically insignificant for transfusion.
Anti-Ch and anti-Rg
Was named in 1960 after Mrs. Gerbich, the first antibody producer.
The Gerbich (020) System
There are currently six high-prevalence Gerbich antigens (…….) and five low-prevalence antigens (…….)
Ge2, Ge3, Ge4, GEPL, GEAT, and GETI
Wb, Lsa, Ana, Dha and GEIS
- The antigen are carried on sialoglycoprotein structures GPC and GPD.
- There are about ______ copies of GPC, and ______ copies of GPD per RBC.
Gerbich Antigen ; 135,000 ; 50,000
- _____ and ____ = encoded by the GYPC gene, located on chromosome 2
at position 2q14.3. - ______ = Gerbich null phenotype
- All were English or North American.
- Ge null Phenotype are elliptocytic
GPC and GPD ; Leach type
Gerbich Negative Phenotypes:
Ge: -2, 3, 4
Type: Yus
Antibody: Anti-Ge2
Gerbich Negative Phenotypes:
Ge: -2, -3, 4
Type: Gerbich
Antibody: Anti-Ge2 or anti-Ge3
Gerbich Negative Phenotypes:
Ge: -2, -3, -4
Type: Leach Type
Antibody: Anti-Ge2 or anti-Ge3
___ phenotype has been found in Mexicans, Israelis, Mediterraneans.
Yus
The Gerbich phenotype is _______ in certain areas of Papua, New
Guinea, and has also been found among Europeans, Africans, Native
Americans, Japanese, and Polynesians.
- Expressed at birth.
- Are resistant to treatment with _____ and _______;
- ____ and ____ are ficin and papain sensitive,
- but ____ is ficin resistant.
polymorphic ; DTT and glycine-acid EDTA ; Ge2 and Ge4 ; Ge3
Gerbich Antibodies
- May be IgM, but most are ___.
- are sometimes clinically significant for transfusion and sometimes not.
- can be eluted from DAT+ cord bloods, but only 3 cases of serious HDFN due to anti-Ge3, and two were children of the same mother.
- babies born to mothers with anti-Ge3 should be monitored for several weeks after birth for anemia.
- _______ most common of the Gerbich antibodies. The antibody made by the Ge:-2,3,4 phenotype individuals
- but it is also more common antibody made by the Ge:-2,-3,4 phenotype and Ge:-2,-3,-4 phenotype individuals.
- ____ is less frequently made by the Ge;-2,-3,4 and Ge:-2,-3,-4
- ______ is a very rare antibody.
IgG ; Anti-Ge2 ; Anti-Ge3 ; Anti-Ge4
In 1965, an antibody was found in a black prenatal patient, Mrs. Cromer, that reacted with all RBCs except her own and two siblings.
- originally thought her antibody recognized an antigen antithetical to ____ of the Rh blood group system.
- the antibody was named ____ in 1975.
The Cromer (021) System ; Goa ; anti-Cra
- The antigens of the Cromer system are carried on __________ (DAF, CD55), a complement-regulator protein.
- The gene ____ is located on chromosome 1 at position 1q32.
- The glycoprotein encoded by the gene is attached to the RBC
membrane through a GPI linkage. - _______ are deficient in DAF so they also lack Cromer antigens.
- The Cromer system has ___ antigens.
- ___ have been classified as high-prevalence antigens and ___ low-prevalence antigens.
- All these antigens are absent from Inab phenotype RBCs, the Cromer null phenotype, which is very rare.
decayaccelerating factor ;
CD55 ;
PNHIII RBCs;
19 ; 15 ; 3
- ______ appears to be a novel Inab-like phenotype with a mutation that affects the expression of the Cromoer antigens.
- The _____ phenotype is typically found in blacks and is not found in whites.
- Three Cromer antigens, ___, ____, and ____, are antithetical;
- ___ is the high-prevalence.
- ____ (low prevalence) and ___ (high prevalence) are also antithetical.
- The ____antigen is of high prevalence
CROM (CROM19) ;
Cr(a-) ;
Tca, Tcb, and Tcc
Tca ;
WESa ; WESb;
Dra
- _____ RBCs have weakened expression of all other high-prevalence Cromer antigens
due to a markedly reduced copy number of DAF. - The Dr(a-) phenotype has been found only among jews from Bakhara and in Japanese.
- Cromer system antigens are resistant to treatment with ______ and ____ but are destroyed by _______, which is used to distinguish specificities in this from other blood group antibodies.
- Cromer antigens are weakened with ____ treatment and are resistant to ______
Dr(a-) ;
ficin and papain ; a-chymotrypsin
DTT ; glycine-acid EDTA.
(cromer antibodies)
- are usually ____, but do not cause HDFN.
- ____ is strongly expressed on placental tissue and will adsorb Cromer antibodies.
- _____ and _____ have been implicated in HTRs, but other examples of these
specificities have not been caused clinical reactions after transfusion of
incompatibilities units. - ______ is the antibody made by individuals with the Cromer null Inab phenotype.
IgG ;
DAF ;
Anti-Cra and Anti-Tca ;
Anti-IFC
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The Knops (022) System
- There are ____ antigens in knop blood group system.
- The system was established when the antigens were shown to be
located on _________ and was named after Mrs. Knops, the first antibody maker. - The gene CR1 is located on ________ at position 1q32.2.
nine ;
complement receptor 1 (CR1) ;
chromosome 1