P/GLOB,Rh

Question 1

• P Blood group Antigen.

- GLOB collection Antigens.

Answer 1

• P1 Ag - P blood group

- Pk and P Ags - GLOB collection

Question 2

The P1 antigen is the receptor for what?

Answer 2

Parvovirus B19 (5th disease)

*entry point into RBCs

Question 3

What antigen is the target of antibodies in paroxysmal cold hemoglobinuria (PCH).

Answer 3

P antigen

-Auto-anti-P antibody

Question 4

The P group phenoytes are defined by reactivity with what antibodies?

Answer 4

• Anti-P1
• Anti-P
• Anti-Pk
• Anti-PP1Pk

Question 5

What is the P1 phenotype?

Answer 5

P1+, P+, Pk-, PP1Pk+

*80% of white; 95% of blacks

Question 6

Individuals with p phenotype (P1-, P-, Pk-, PP1Pk-) make a potent ____ antibody.

Answer 6

Anti-PP1Pk

Question 7

Anti-PP1Pk antibodies may be associated with what?

Answer 7

• Delayed Hemolytic transfusion reaction
• HDFN
• 1st trimester spontaneous abortion

Question 8

Anti-P1 is agglutinated by what? (3)

Answer 8

• Hydatid cyst fluid
• Pigeon egg whites
• Turtledove egg whites

Question 9

Anti-P1 titers may be elevated in what conditions/situations?

Answer 9

• Echinococcal infection (Hydatid cyst)

- Bird Handlers

Question 10

P(k) antigen is the receptor for binding what in renal epithelium?

Answer 10

• Shiga toxin

- E. coli toxins

Question 11

Individuals with P2 phenotype make an Anti-P1 25% of the time, describe the antibodies:

• Warm/Cold
• IgG/IgM
• Clinical signficance

Answer 11

• Cold
• IgM
• Insignificant

Question 12

Auto-anti-P antibody characteristics. (4)

Answer 12

• Paroxysmal cold hemoglobinuria
• Biphasic IgG
• Binds in cold temps, hemolyzes at 37
• “Donath-Landsteiner biphasic hemolysin”
• Seen following viral infection in children (syphilis historically)

Question 13

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-R1

Answer 13

DCe

Question 14

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-R2

Answer 14

DcE

Question 15

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-R0

Answer 15

Dce

Question 16

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-r’

Answer 16

dCe

Question 17

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-r’’

Answer 17

dcE

Question 18

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-r

Answer 18

dce

Question 19

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-Rz

Answer 19

DCE

Question 20

Wiener’s “Haplotype” - Fisher-Race Equivalents:

-r(y)

Answer 20

dCE

Question 21

What are the frequency of the different Rh combinations in WHITES?

Answer 21

R1>r>R2>R0

Question 22

What are the frequency of the different Rh combinations in BLACKS?

Answer 22

R0>r>R1>R2

Question 23

Rh antigens are polypeptide antigens encoded by what two closely linked gene loci? (chromosome?)

Answer 23

RHD & RHCE

-Chr1

Question 24

What additional proteins associate with the Rh complex?

Answer 24

• LW

- Duffy (Fy)

Question 25

What helps explain the possibility of "partial D" phenotypes?

Answer 25

Multitude of extracellular domains *size and intricacy result in multitude of epitopes and antigens

Question 26

What is the most common Rh- genotype?

Answer 26

r/r (dce/dce) *Whites 40%; Blacks 30%

Question 27

Rh null individuals have no Rh antigens, they also have diminished expression of what other antigens? (5)

Answer 27

- LW - Fy5 - S/s - U

Question 28

Rh null individuals have no Rh antigens, what clinical manifestations are they associated with? (3)

Answer 28

- Osmotic fragility - Chronic hemolysis - Stomatocytosis

Question 29

What antibody will form in a Rh null patient who received Rh- RBCs?

Answer 29

Anti-Rh29 | -Anti-total Rh antibody

Question 30

Weak D is what type of defect?

Answer 30

Quantitative defect in D antigen | -Less D than normal

Question 31

T/F: Persons with weak D do NOT form an anti-D antibody.

Answer 31

True

Question 32

Weak D is defined historically by weak reactivity with anti-D reagent, typified by the following reactions:

Answer 32

- Negative at IS with anti-D reagent - Negative after 37 incubation with anti-D reagent - Positive at AHG phase with anti-D (IAT)

Question 33

What are the possible reasons for weak D?

Answer 33

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

Question 34

When do you perform weak D test?

Answer 34

All D-negative DONORS *Weak D RBCs could induce anti-D in a D(-) recipient

Question 35

What non-donor group needs weak D testing?

Answer 35

D(-) babies born to D(-) mothers

Question 36

T/F: Weak D moms do NOT need RhIG prophylaxis.

Answer 36

True

Question 37

What is the definition of partial D?

Answer 37

Alteration in 1 of the epitope sequences of the D gene

Question 38

What is the result of partial D?

Answer 38

D antigen with some, but not all, epitopes *Persons with partial D may form anti-D antibody

Question 39

T/F: Transufusion of partial D cells into a D Negative recipient may cause sensitization.

Answer 39

True

Question 40

Partial D women and pregnancy.

Answer 40

-At risk for forming anti-D antibodies with D+ preganancy

Question 41

How should partial D recipient women be treated?

Answer 41

D Negative

Question 42

How is partial D frequently identified?

Answer 42

Coexistence of D expression and anti-D antibodies

Question 43

Rh antibodies are __ antibodies that are _______.

Answer 43

IgG | acquired through exposure

Question 44

What is the most immunogenic of all the non-ABO antigens?

Answer 44

D antigen

Question 45

What is the rate of sensitization, when Rh+ blood is transfused to Rh- recipients in the ER setting?

Answer 45

20-30%

Question 46

All Rh antibodies except what, display dosage?

Answer 46

Anti-D

Question 47

T/F: All Rh antigens are enhanced by enzymes.

Answer 47

True

Question 48

If anti-E is detected in the serum, the additional presence of what antibody should be suspected? -Why?

Answer 48

anti-c | -Anti E individuals have R1R1 phenotype (DCe/DCe), and have likely been transfused with R2 blood (DcE)

Question 49

anti-c may be undetectable, but is a common cause of what?

Answer 49

Delayed hemolytic transfusion reaction

Question 50

G antigen is found on ALL __ RBCs and most __ RBCs.

Answer 50

G antigen is found on all D+ RBCs and most C+ RBCs

Question 51

Serologically anti-G antibodies can mimic what?

Answer 51

anti-D and anti-C *multiple absorption/elution studies can distinguish anti-G from anti-D and anti-C

Question 52

Anti-f is an antibody against what?

Answer 52

compound antigen ce

Question 53

T/F: Anti-f is the most common alloantibody directed against compound Rh antigens.

Answer 53

True

Question 54

Anti-f is primarily found in persons with what Rh phenotype?

Answer 54

DCe/DcE (R1R2)