P1PK and GLOB

Question 1

What antigens are in the P1PK BGS?

Answer 1

P1 - polymorphic 80% white = P1+
Pk - high freq
NOR - high freq

Question 2

What antigens are in the Globoside BGS?

Answer 2

P = high freq (99.9%)

Uses different enzyme to add sugar to chain

Question 3

What antigens are in the Globoside Collection?

Answer 3

LKE and PX2 are both high frequency

Question 4

P1 soluble antigen is found in?

Answer 4

Pigeon Egg Whites
Hydatid Cyst Fluid
liver flukes
Used in neutralization techniques

Question 5

P1 and PK antigens are located on what cells?

Answer 5

Lymphs, Granulocytes, Mono’s, and PLT’s

Question 6

What causes P2 phenotype?

Answer 6

P2 is caused by 2 amino acid change to A4GALT enzyme = unable to form P1 from paragloboside chains
P2 people lack P1 and can make anti-P1

Question 7

How do you determine if they are P2 phenotype?

Answer 7

If patient types as P1 negative must type person for P antigen. Should type as P positive, or they may be a rare P2K or p (null) phenotype

Question 8

Antigens present in P1 phenotype?

Answer 8

P1, P, and Pk (Pk may type as negative because P is formed from Pk)

Question 9

Antigens present in P2 phenotype?

Answer 9

P and Pk (Pk may type as negative because P is formed from Pk)
Make anti-P1

Question 10

P1k

Answer 10

P negative = Can make anti-P

Have P1 and Pk

Question 11

P2K

Answer 11

Pk only present

Can make anti-P1 and anti-P

Question 12

p

Answer 12

Null - no P, P1, or Pk

Can make Anti-PP1PK (Anti-Tja)

Question 13

Frequency of P1 phenotype?

Answer 13

Whites = 80%
Vietnamese/cambodians = 20%

Question 14

Frequency of P2 phenotype?

Answer 14

Whites = 20%
Vietnamese/cambodians = 80%

Question 15

Frequency of P1k, P2k. and p?

Answer 15

Extremely rare

p seen in northern Ohio amish people

Question 16

How is P1 antigen formed?

Answer 16

A4GALT adds a galactose on to paragloboside chain

Paragloboside is precursor for Type 2 H chains and PX2

Question 17

How is Pk antigen formed?

Answer 17

A4GALT enzyme adds galactose to Lactosylceramide

Question 18

How is P antigen formed?

Answer 18

P antigen is formed from Pk

B3GALNT-1 adds GalNAc to Pk > P antigen

Question 19

How is NOR antigen formed?

Answer 19

Formed from P antigen

A4GALT enzyme adds galactose to P antigen

Question 20

How is LKE antigen formed?

Answer 20

Formed from P antigen

A4GALT enzyme adds galactose and sialic acid is added to form LKE

Question 21

Characteristics of P1 antigen

Answer 21

Weaker on cord cells until 10 years of age
Antigen varies in strength and is weaker on older cells
Enzymes enhance reactivity
Not destroyed by Papain, Ficin, EGA, DTT, Chloroquine

Question 22

Allo anti-P1

Answer 22

Found in P2 people
IgM naturally occuring
Reacts best at RT or below 25C - Cold saline agglutin
Give XM compatible blood

Question 23

Characteristics of Pk antigen

Answer 23

Expressed on cord cells
Expressed on cells except p null cells 
- Weak on P1 and P2 because hidden
High frequency antigen
May provide protection against HIV

Question 24

Anti-PP1Pk

Answer 24

Seen with Anti-Pk (can adsorb out)
Formed in p null individuals
IgM and a mixture of IgG/IgM
Wide terminal range-reacts at RT, 37C and AHG
Binds complement
Naturally occurring
POTENT hemolysin
Causes abortions, TRN RXN, and HDFN

Question 25

NOR antigen

Answer 25

Low frequency part of P1PK BGS NOR+ cells are agglutinated by most adult sera so its thought to be related to polyagglutination Enzyme enhances Anti-NOR is IgM

Question 26

How is NOR antigen formed?

Answer 26

Galactose added to GLoboside or P antigen | Single amino acid change to A4GALT responsible

Question 27

Where is P antigen found?

Answer 27

Found in RBC, lymph, mono's, and placenta | Expressed on Cord cells

Question 28

What populations are P negative found in?

Answer 28

Negative found in Scandinavians, Isrealis, Amish, Finns, Arabs

Question 29

How is P antigen formed?

Answer 29

P is formed by B3GALNT adding a GalNAc to Pk

Question 30

Auto anti-P

Answer 30

Causes PCH Powerful IgG Biphasic hemolysin, complement binding Positive Donath-Landsteiner test but routine testing is negative. DAT is +/- More common in children

Question 31

What is PCH?

Answer 31

Antibody/antigen complexes auto anti-P are formed at lower temps in peripheral blood and when temp is raised complement is activated and hemolysis occurs

Question 32

Allo anti-P

Answer 32

Rare antibody Potent hemolysin with wide thermal range may cause spontaneous abortion

Question 33

Decreased P1 antigen is seen in...

Answer 33

In(Lu) phenotype = reduced expression of antigens in the Lutheran system, P1, Inb, and AnWj antigens

Question 34

LKE antigen

Answer 34

Expression decreased in Secretors LKE S+ = 80-90% LKE W+ = 10-20% 1-2% are LKE negative (P1k, P2K, p)

Question 35

How is LKE antigen formed?

Answer 35

PK > P > + sialic acid = LUKE antigen

Question 36

Anti-LKE

Answer 36

Rare IgM with some complement binding not clinically significant

Question 37

PX2 antigen

Answer 37

High freq Not found in P1k or P2k Highly expressed in p individuals

Question 38

Anti-PX2

Answer 38

IgG or mixture of IgG/IgM Naturally occurring Enhanced by enzymes

Question 39

What disease is Pk antigen associated with?

Answer 39

Receptor for shiga toxin causing shigella dysentery

Question 40

What disease is P antigen associated with?

Answer 40

Receptor for parvovirus