Rh G Flashcards
G antigen is present on most ___ and all ___ RBCs
most D-positive and all C-positive
G antigen results from the amino acid serine at position 103 on the __
RhD, RhCe, and RhCE
all ___ and ___ cells are G positive
C positive and D positive
G antigen are originally found in an rr person who received ____ RBCs
D+
C-
E-
c+
e+
t or f: amino acids encoded by exon 2 of RHC are identical to those encoded by exon 2 of RHCe
false, identical to those encoded by exon of RHD
t or f: there are some cases where Rh negative individual who received Rh negative blood still reacted
TRUE.
the donor was C positive and thus G+ and the antibody produced is actually anti-G not anti D and anti-C.
G antigen is important for ___ patients because production of anti-G also is a candidate for RhIG
obstetric patients
if the obstetric patient has produced anti-G and not anti-D, then she is considered a candidate for?
RhIG
ability of a particular substance (antigen or epitope) to provoke an immune response to the body of a human or animal
immunogenecity
immunogenecity of Rh
D > c > E > C > e
enumerate the Rh functions
- structural integrity of red cells
- ammonia and CO2 transporters
about 1% of D-positive individuals type as ___
weak D
weak D is formerly known as?
Du
test requirement for people with RBC that possess D antigen
indirect antiglobulin test
serologic weak D is noted when initial anti-D testing is ___
negative or less than or equal to 2+ strong
t or f: D positive RBCs fail to agglutinate directly with anti-D typing reagents
true
not a new antigen because people did not produce anti-Du but anti-D
weak D (Du type)
t or f: individuals with RBCs carrying partial D antigen cannot produce anti-D if they are missing epitopes of the D antigen
false, it can produce
enumerate the weak D types
- position effect
- quantitative
- partial-D antigen
this mechanism of D antigen is that the Rh antigen on RBC is normal (D antigen is structurally complete), but the steric arrangement of the C antigen in relationship to the D antigen appears to interfere with the expression of D antigen.
position effect - C in trans to RHD
people with this blood type can receive D positive RBCs
position effect - C in trans to RHD
in this mechanism, red cells fails to react or reacts weakly to agglutination tests (but will react in IAT)
weak D quantitative
this is from the inheritance of RHD genes that code for weakened expression of the D antigen
weak D quantitative
mutations in the RHD gene occur causing changes in ___ present in transmembrane region of the RHD protein, causing conformational changes in the protein
changes in amino acids
mutation in RHD gene causing conformation changes in the?
protein
T or F: in position effect, the changes does not alter or remove any D epitopes, therefore, production of anti-Rh is not possible
false, quantitative
production of anti-Rh is not possible in what category of weak D?
quantitative
changes of amino acids are observed “inside” the red cells, therefore, antibody production is less likely
what category/type of weak D?
quantitative
weak forms of D antigen is less immunogenic than the ___
normal D positive blood
weak D quantitative is common in?
blacks
in this mechanism/type, one or more D epitopes within the entire D protein is missing or altered
partial D / D mosaic / D variant
partial D is also called ___
D mosaic or D variant
weaker or may not react at all (but some have normal reaction)
identify the type.
partial D
T or F: in 1970s, individuals who were type D-positive but produced an anti-D that reacted with all D-positive samples except their own
false, 1950s
they postulated that the D antigen is made of antigenic subparts, genetically determined, that could be absent in rare instances
Wiener and Unger
if an individual lacks one or more epitopes, of the total D antigen, this antibody can be made to the missing epitopes if exposed to the RBCs that possess the complete D antigen
alloantibody
persons who classified the antigens
Patricia Tippett and Ruth Sanger
they tested anti-D sera from D positive people with RBCs from other D-positive people who also made anti-D
Patricia Tippett and Ruth Sanger
Patricia Tippett and Ruth Sanger used this antibodies to classify
monoclonal (MAb-D) antibodies
this type has 7 categories with assigned roman numerals
partial D
t or f: serologic typing and molecular analysis are not required to accurately categorize the partial-D types
false, required
Partial D antigens are classified and are attributed to hybrid genes resulting from portions of the __ being replaced by portions of the ___ gene
portions of the RHD gene being replaced by portions of the RHCE gene
resulting protein contains a portion of RhD and RhCE in various combinations
partial D
partial D occurs __ to the RBC membrane
external
what particular location does partial D occur in the RBC membrane?
extracellular loop or portion to the RhD protein
if an individual with hybrid RhD-RhCe-RhD protein is exposed to RBCs possessing normal RhD protein, what will they make?
antibody to the portion of the RhD protein they are missing
anti-D made by individuals expressing partial D can cause?
- hemolytic disease of the fetus and newborn
- hemolytic transfusion reactions
once anti-D is identified, what will blood will you use for transfusion?
Rh negative
RhCE protein can express ___ detected by some monoclonal anti-D
RhD epitopes
few individuals possess these unusual proteins
RhCE protein
t or f: anti-D will show negative reactivity even though the D epitope is on the RhCE protein
false, will show positive reactivity
examples of unusual phenotypes who possess these unusual proteins and will show positive reactivity even though D epitope is on the RhCE protein
- DHAR
- CeCF (Crawford)
R0Har “DHAR” results from what hybrid gene?
RHCE-RHD-RHCE
in this phenotype, only a small portion of RHD is inserted into the RHCE gene
R0Har “DHAR”
R0Har “DHAR”
if paired to a normal RHD gene, the person will have Rh?
Rh-positive
these individuals should be classified as RhD-negative since they lack RhD protein
what phenotype?
R0Har “DHAR”
what RH is the Crawford phenotype?
RH34
pero RH43 kang sir :>
this phenotype are found in individuals of African descent
Crawford antigen (ceCF)(Rh34)
Crawford antigen (ceCF)(Rh43) is due to ___
a. small portion of RHD is inserted
b. specific amino acid change
due to specific amino acid change in the RhCE sequence
results for an RhD epitope on the RhCE protein, what phenotype?
Crawford antigen (ceCF)(Rh43)
this phenotype has very low prevalence
Crawford antigen (ceCF)(Rh43)
Phenotype in individuals whose RBCs possess an extremely low number of D antigen sites that most reagent anti-D are unable to detect
Del (el is naa sa ubos)
only way to detect the D antigen in Del phenotype
adsorbing and eluting anti-D
Mutant, RHD gene that alters expression of the RhD protein
identify what phenotype
Del
Del is due to splice site mutation or deletion that results in the absence of amino acids encoded by what exon?
exon 9 of RHD in Asians (or M295I mutation in whites)
this phenotype is common in Asian (10-30% population)
Del
Del phenotype has high incidence in people?
- Hong kong
- Chinese
- Japanes
this phenotype may be typed as D negative and can be found only when they stimulate production of anti-D in D negative individuals
Del
process of gathering/pulling molecules onto the surface
employed in Del phenotype
Adsorbing
process of removing molecules from a source or cellular entity.
employed in Del phenotype
elution
in Del phenotype, the Red Cells are incubated with __ at ___.
anti-D at 37C
gives time to anti-D to bind the antigens present
Del phenotype
what is adsorbed?
what is eluted?
adsorbed = red cells
eluted = anti-D
