RH GROUP PPT 1 Flashcards
_________ is described as a highly complex blood group system
Rh blood group system
_______ is a critical component of pre transfusion and prenatal testing.
RhD typing
(history of RH group)
1939 _________ - described a hemolytic transfusion reaction in an obstetrical patient.
Levine and Stetson
(history of RH group)
An antibody was isolated from the mother’s serum that reacted at both _____ and _____ with the father’s RBCs.
37°C and 20°C
(history of RH group)
Antibody specificity was not identified, but it was found to react with 80% of cells tested and was suspected to be a ________ to a factor on the fetal cells
maternal antibody
(history of RH group)
______ and _________- described an antibody made by guinea pigs and rabbits when they were transfused with rhesus macaque monkey RBCs.
Landsteiner and Wiener
(history of RH group)
Agglutinated 85% of human RBCs and was named anti-Rh after the _________
Later named as _________
rhesus monkey ; “anti LW”
Terminologies
__________ : DCE Terminology
_________: Rh-Hr Terminology
_________ : Alphanumeric Terminology
______________: Updated Numeric Terminology
Fisher-Race
Wiener
Rosenfield and Coworkers
International Society of Blood Transfusion Committee
(Fisher-Race: DCE Terminology)
Mid-1940s ________ - postulated that the antigens of the system were produced by three closely linked genes.
Fisher and Race
(Fisher-Race: DCE Terminology)
Each gene was responsible for producing one antigen on the _______
RBC surface.
(Fisher-Race: DCE Terminology)
Fisher and Race named the antigens of the system _____________. Now it is known that “____” represents the absence of D antigen; however, the term continues to be utilized with Fisher-Race terminology as a placeholder
D, d, C, c, and E, e ; “d”
According to the Fisher-Race theory, an individual inherits
a set of ______ from each parent (i.e., one D or d, one C or
c, and one E or e).
The combination of genes inherited from one parent is called a _______
For example, if one parent
has the genes D, C, and e, then the haplotype is written as
_____
RH genes ; haplotype ; DCe.
The pairing of maternal and paternal haplotypes determines the offspring’s ________ (the RH genes inherited from
each parent).
The genotype is written as two haplotypes separated by a / (i.e., DCe/Dce).
genotype
(Wiener: Rh-Hr Terminology)
Wiener believed there was one _____ responsible for defining Rh that produced an agglutinogen containing three Rh factors.
gene
(Wiener: Rh-Hr Terminology)
Each _____ is an antigen recognized by an antibody.
factor
(Wiener: Rh-Hr Terminology)
The original Wiener nomenclature named the five
common Rh antigens as _____________ but these
terms are no longer used in favor of a modified form of
Wiener notation.
Rho, rh’, rh”, hr’, and hr”
(Wiener: Rh-Hr Terminology)
In the modified Wiener nomenclature, an agglutinogen is
described by a letter and symbol assigned based on the factors present.
The uppercase __ denotes the presence of the D antigen.
The lowercase __ indicates the absence of D antigen.
The presence of the C antigen is indicated by a ___ or a single
prime (__).
The c antigen is implied when there is ___ 1 or ‘ indicated.
The E antigen is indicated by a __ or double prime (__)
The e antigen is implied when __ 2 or “ is indicated.
That is,
- __ is the same as DCe;
- __ denotes Ce; and
- ___ is equivalent to Dce.
The presence of E is indicated by the Arabic number 2 or double prime (“).
Lowercase e is implied when
there is no 2 or “ indicated—that is,
- R2 is the same as DcE;
- r” denotes cE, and
- r is equivalent to ce (again, it is assumed that a c antigen is present).
When both C and E are present, the letter ___ or ___ is used.
Rz denotes DCE, whereas ry represents CE.
- R
- r
- 1 or ‘
- no (walang 1 or ‘)
- 2 or “
- no (walang 2 or “)
- R1
- r′
- Ro
- z or y
(Wiener: Rh-Hr Terminology)
Phenotypes of less common Rh types such as ____ and ____ are written as stated.
The genotype for the Rhnull that arises from an amorphic gene at both Rh loci is written
as and pronounced “little r double bar.”
Rhnull and Rhmod ; (rr may double bar sa taas)
(Wiener: Rh-Hr Terminology)
________ allows one to convey Rh
antigens inherited on one chromosome or haplotype and
makes it easier to discuss a genotype.
Modified Wiener terminology
(Wiener: Rh-Hr Terminology)
Fisher-Race nomenclature may be converted to ________ and vice
versa.
Wiener nomenclature
(Wiener: Rh-Hr Terminology)
It is important to remember that an agglutinogen in Wiener nomenclature actually represents the ______ of a
single haplotype expressing three different antigens.
In the Wiener nomenclature, there is no designation for the absence of D antigen. By using these designations, the laboratorian should be able to recognize immediately which
antigens are present on the RBCs.
presence
The ISBT adopted a six-digit number for each authenticated antigen belonging to a blood group system.
(International Society of Blood Transfusion Committee: Updated Numeric Terminology)
(Molecular Genetics)
_________: proposed that the Rh locus contains three distinct genes that control production of their respective antigens
FISHER and RACE
(Molecular Genetics)
______: correctly proposed two RH genes, RHD and RHCE, that control expression of Rh antigens.
TIPPETT
(RH GENES)
_____ AND _____ are two closely linked genes located on chromosome 1 that control expression of Rh proteins
RHD and RHCE
(RH GENES)
The gene _____ codes for the presence or absence of the RhD protein.
The second gene ____ codes for either RhCe, RhcE, Rhce, or RhCE proteins
RHD ; RHCE
(RH GENES)
RHD and RHCE are _______, which means that all products inherited typically produce antigens detectable on RBCs.
RHD and RHCE genes each have ____ exons and are 97% identical.
Each gene has a number of alleles, most of which have been identified through __________
codominant ; 10 ; molecular testing techniques.
(RH GENES)
Numerous ________ have been described in the RH genes.
Greater than ____ alleles have been determined in the RHD gene, and ____ alleles have been found in the RHCE allele
and the number continues to grow.
mutations ; 250 ; 50
(RHAG)
Another gene important to Rh antigen expression is RHAG,
and it resides on chromosome ___. The product of this gene is _____
6 ; RHAG
This polypeptide is very similar in structure to the Rh proteins, with the difference being that it is glycosylated (carbohydrates attached). Within the RBC membrane, it forms complexes with the Rh proteins.
(RHAG)
______ is termed a coexpressor and must be present for successful expression of the Rh antigens.
However, by itself, this glycoprotein does not express any Rh antigens.
When mutations in the RHAG gene occur, it can result in
missing or significantly altered ____ and _____ proteins,
affecting antigen expression.
RhAG ; RhD and RhCE
(Rh-Positive Phenotypes)
RH genes are inherited as __________.
Rh-positive individuals inherit one or two ________-, which result in expression of RhD antigen and are typed Rh-positive. In
addition to the RHD gene(s), two RHCE genes are inherited,
one from each parent.
codominant alleles ;RHD genes
(Rh-Positive Phenotypes)
Numerous mutations in the RHD gene have been discovered that cause weakened expression of the RhD antigen detected in routine testing. This is generally termed ________
or weak expression of D.
weak D
(Rh-Negative Phenotypes)
Rh-negative phenotypes are so called because the RBCs lack
detectable _______-
D antigen.
(Rh-Negative Phenotypes)
Rh-negative individuals can arise from several _____
pathways.
(Rh-Negative Phenotypes)
The most common Rh-negative phenotype results from the complete deletion of the RHD gene—that is, the individuals possess no ____ gene but have inherited two _____ genes.
RHD ; RHCE
(BIOCHEMISTRY)
Rh antigens reside on ___________ and are an integral part of the RBC membrane.
transmembrane proteins
(BIOCHEMISTRY)
_____: both encode for proteins composed of 416 amino acids that traverse the cell membrane 12 times
- Their proteins differ by only 32 to 35 amino acids
- Amino acid position _____ is important in determining C or c expression and position 226 differentiates E from e
RHCE ; 103
(BIOCHEMISTRY)
- ___________: measured the number of D antigen sites on a variety of Rh phenotypes
- ____________: greatest number of D antigen sites
- _____ cells possess the largest number of D antigen sites among commonly encountered genotypes
HUGHES-JONES and COWORKERS ; Rare Rh phenotype D (D—) ; R2R2
(BIOCHEMISTRY)
- ___________ showed they may have a role in transporting ammonia; may be CO2 transporters
WESTHOFF and COLLEAGUES
(Weak D: Variations of D Antigen Expression)
Rh antigens are highly _________; the D antigen is the most _______.
immunogenic ; potent
(Weak D: Variations of D Antigen Expression)
Eighty-five percent of the general population is _________-, with 15% typing as _______
Rh-positive ; Rh-negative
(Weak D: Variations of D Antigen Expression)
_________ and ___________ populations have significantly higher percentages of Rh-positive individuals (92.7% and 92.9%, respectively)
Hispanic and African American
(Weak D: Variations of D Antigen Expression)
______ was the most common cause of HDFN until ______ globulin was introduced
Requires an ___________ to detect the presence of D antigen
____ – weaker expression of the rh system on the RBC.
Anti-D ; Rhimmune ; indirect antiglobulin test ; Du
(C in Trans to RHD)
_____________: FIRST mechanism that may result in weakened expression of D antigen
Position effect or gene interaction effect
(C in Trans to RHD)
Allele carrying RHD is _____ (or in the opposite haplotype) to the allele carrying C
- This interference with D expression does not occur when the C gene is inherited in the cis position to RHD, such as DCe/dce
- Molecular studies would differentiate the two types. Practically speaking, this is unnecessary because the D antigen is structurally complete
trans
(C in Trans to RHD)
It is not possible to serologically distinguish genetic weak D from the _________-
position effect weak D
(Weak D)
SECOND mechanism results from inheritance of _____ that code for a weakened expression of the ______
RHD genes ; D antigen
(Weak D)
D antigens expressed appear to be complete but fewer in _____
number
(Weak D)
_____________ described the classification of weak D RBCS based on single nucleotide polymorphisms (SNP)
WAGNER, GASSNER, and others
(Weak D)
Individuals with weak D phenotype rarely make ______, since the RhD antigens are present as expected, but protein changes occur “inside” the red blood cell
anti-D
(Weak D)
- Rarely make ____
- Type ________: most common mutations found in individuals of European ancestry
anti-D ; 1 through 3
3RD mechanism one or more D epitopes within the entire D protein is either missing or altered.
(Partial D)
(Partial D)
___________: postulated that the D antigen is made of antigenic subparts, genetically determined, that could be absent in rare instances
WIENER and UNGER
(Partial D)
__________ worked with RBCs and sera of partial-D individuals to classify these antigens
If an individual with a hybrid RhD-RhCe-RhD protein is exposed to red blood cells possessing normal RhD protein, they will make _________ to the portion of the RhD protein they are missing
TIPPETT and SANGE ; antibody
(Partial D)
_______: hemolytic disease of the fetus and newborn (HDFN) or transfusion reactions, or both
Anti-D
(Del)
Red blood cells possess an extremely ______ of D antigen sites that most reagent anti-D are unable to detect.
low number
(Del)
This procedure requires incubating anti-D with the RBCs in question at _____ followed by eluting the anti-D off the adsorbed red blood cells.
The 37°C incubation provides time for the anti-D to _____ to the few D antigen sites present on these red blood cells
37°C ; bind
(Del)
Del individuals of Southeast Asian descent have not been reported to make anti-D in response to transfusion or pregnancy, but there have been a few instances of anti-D production in _______ individuals
Caucasian
(D Epitopes on RhCE Protein)
_____ protein can express RhD epitopes
RhCE
(D Epitopes on RhCE Protein)
When typed with anti-D will show ______ reactivity even though the D epitope is on the RhCE protein
positive
(D Epitopes on RhCE Protein)
_____, also known as DHAR, classified as RhD-negative
- Results from a hybrid gene RHCE-RHD-RHCE where only a small portion of RHD is inserted into the RHCE gene
R0 Har
(D Epitopes on RhCE Protein)
___________: results from a specific amino acid change in the RHce gene, resulting in an RhD epitope on the Rhce protein
CRAWFORD (ceCF) phenotype:
