P/GLOB,Rh Flashcards
- P Blood group Antigen.
- GLOB collection Antigens.
- P1 Ag - P blood group
- Pk and P Ags - GLOB collection
The P1 antigen is the receptor for what?
Parvovirus B19 (5th disease)
*entry point into RBCs
What antigen is the target of antibodies in paroxysmal cold hemoglobinuria (PCH).
P antigen
-Auto-anti-P antibody
The P group phenoytes are defined by reactivity with what antibodies?
- Anti-P1
- Anti-P
- Anti-Pk
- Anti-PP1Pk
What is the P1 phenotype?
P1+, P+, Pk-, PP1Pk+
*80% of white; 95% of blacks
Individuals with p phenotype (P1-, P-, Pk-, PP1Pk-) make a potent ____ antibody.
Anti-PP1Pk
Anti-PP1Pk antibodies may be associated with what?
- Delayed Hemolytic transfusion reaction
- HDFN
- 1st trimester spontaneous abortion
Anti-P1 is agglutinated by what? (3)
- Hydatid cyst fluid
- Pigeon egg whites
- Turtledove egg whites
Anti-P1 titers may be elevated in what conditions/situations?
- Echinococcal infection (Hydatid cyst)
- Bird Handlers
P(k) antigen is the receptor for binding what in renal epithelium?
- Shiga toxin
- E. coli toxins
Individuals with P2 phenotype make an Anti-P1 25% of the time, describe the antibodies:
- Warm/Cold
- IgG/IgM
- Clinical signficance
- Cold
- IgM
- Insignificant
Auto-anti-P antibody characteristics. (4)
- Paroxysmal cold hemoglobinuria
- Biphasic IgG
- Binds in cold temps, hemolyzes at 37
- “Donath-Landsteiner biphasic hemolysin”
- Seen following viral infection in children (syphilis historically)
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-R1
DCe
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-R2
DcE
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-R0
Dce
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-r’
dCe
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-r’’
dcE
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-r
dce
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-Rz
DCE
Wiener’s “Haplotype” - Fisher-Race Equivalents:
-r(y)
dCE
What are the frequency of the different Rh combinations in WHITES?
R1>r>R2>R0
What are the frequency of the different Rh combinations in BLACKS?
R0>r>R1>R2
Rh antigens are polypeptide antigens encoded by what two closely linked gene loci? (chromosome?)
RHD & RHCE
-Chr1
What additional proteins associate with the Rh complex?
- LW
- Duffy (Fy)
What helps explain the possibility of “partial D” phenotypes?
Multitude of extracellular domains
*size and intricacy result in multitude of epitopes and antigens
What is the most common Rh- genotype?
r/r (dce/dce)
*Whites 40%; Blacks 30%
Rh null individuals have no Rh antigens, they also have diminished expression of what other antigens? (5)
- LW
- Fy5
- S/s
- U
Rh null individuals have no Rh antigens, what clinical manifestations are they associated with? (3)
- Osmotic fragility
- Chronic hemolysis
- Stomatocytosis
What antibody will form in a Rh null patient who received Rh- RBCs?
Anti-Rh29
-Anti-total Rh antibody
Weak D is what type of defect?
Quantitative defect in D antigen
-Less D than normal
T/F: Persons with weak D do NOT form an anti-D antibody.
True
Weak D is defined historically by weak reactivity with anti-D reagent, typified by the following reactions:
- Negative at IS with anti-D reagent
- Negative after 37 incubation with anti-D reagent
- Positive at AHG phase with anti-D (IAT)
What are the possible reasons for weak D?
Mutated form of RHD (MC)
-point mutation in membrane or inner part of RHD leading to alteration in antigen expression
RHCe on opposite chromosome to RHD (“C in trans”) inhibits D expression
When do you perform weak D test?
All D-negative DONORS
*Weak D RBCs could induce anti-D in a D(-) recipient
What non-donor group needs weak D testing?
D(-) babies born to D(-) mothers
T/F: Weak D moms do NOT need RhIG prophylaxis.
True
What is the definition of partial D?
Alteration in 1 of the epitope sequences of the D gene
What is the result of partial D?
D antigen with some, but not all, epitopes
*Persons with partial D may form anti-D antibody
T/F: Transufusion of partial D cells into a D Negative recipient may cause sensitization.
True
Partial D women and pregnancy.
-At risk for forming anti-D antibodies with D+ preganancy
How should partial D recipient women be treated?
D Negative
How is partial D frequently identified?
Coexistence of D expression and anti-D antibodies
Rh antibodies are __ antibodies that are _______.
IgG
acquired through exposure
What is the most immunogenic of all the non-ABO antigens?
D antigen
What is the rate of sensitization, when Rh+ blood is transfused to Rh- recipients in the ER setting?
20-30%
All Rh antibodies except what, display dosage?
Anti-D
T/F: All Rh antigens are enhanced by enzymes.
True
If anti-E is detected in the serum, the additional presence of what antibody should be suspected?
-Why?
anti-c
-Anti E individuals have R1R1 phenotype (DCe/DCe), and have likely been transfused with R2 blood (DcE)
anti-c may be undetectable, but is a common cause of what?
Delayed hemolytic transfusion reaction
G antigen is found on ALL __ RBCs and most __ RBCs.
G antigen is found on all D+ RBCs and most C+ RBCs
Serologically anti-G antibodies can mimic what?
anti-D and anti-C
*multiple absorption/elution studies can distinguish anti-G from anti-D and anti-C
Anti-f is an antibody against what?
compound antigen ce
T/F: Anti-f is the most common alloantibody directed against compound Rh antigens.
True
Anti-f is primarily found in persons with what Rh phenotype?
DCe/DcE (R1R2)
