P1PK and GLOB Flashcards

1
Q

What antigens are in the P1PK BGS?

A

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

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2
Q

What antigens are in the Globoside BGS?

A

P = high freq (99.9%)

Uses different enzyme to add sugar to chain

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3
Q

What antigens are in the Globoside Collection?

A

LKE and PX2 are both high frequency

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4
Q

P1 soluble antigen is found in?

A

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

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5
Q

P1 and PK antigens are located on what cells?

A

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

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6
Q

What causes P2 phenotype?

A

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

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7
Q

How do you determine if they are P2 phenotype?

A

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

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8
Q

Antigens present in P1 phenotype?

A

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

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9
Q

Antigens present in P2 phenotype?

A

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

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10
Q

P1k

A

P negative = Can make anti-P

Have P1 and Pk

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11
Q

P2K

A

Pk only present

Can make anti-P1 and anti-P

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12
Q

p

A

Null - no P, P1, or Pk

Can make Anti-PP1PK (Anti-Tja)

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13
Q

Frequency of P1 phenotype?

A
Whites = 80%
Vietnamese/cambodians = 20%
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14
Q

Frequency of P2 phenotype?

A
Whites = 20%
Vietnamese/cambodians = 80%
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15
Q

Frequency of P1k, P2k. and p?

A

Extremely rare

p seen in northern Ohio amish people

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16
Q

How is P1 antigen formed?

A

A4GALT adds a galactose on to paragloboside chain

Paragloboside is precursor for Type 2 H chains and PX2

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17
Q

How is Pk antigen formed?

A

A4GALT enzyme adds galactose to Lactosylceramide

18
Q

How is P antigen formed?

A

P antigen is formed from Pk

B3GALNT-1 adds GalNAc to Pk > P antigen

19
Q

How is NOR antigen formed?

A

Formed from P antigen

A4GALT enzyme adds galactose to P antigen

20
Q

How is LKE antigen formed?

A

Formed from P antigen

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

21
Q

Characteristics of P1 antigen

A

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

22
Q

Allo anti-P1

A

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

23
Q

Characteristics of Pk antigen

A
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
24
Q

Anti-PP1Pk

A
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
25
Q

NOR antigen

A

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

26
Q

How is NOR antigen formed?

A

Galactose added to GLoboside or P antigen

Single amino acid change to A4GALT responsible

27
Q

Where is P antigen found?

A

Found in RBC, lymph, mono’s, and placenta

Expressed on Cord cells

28
Q

What populations are P negative found in?

A

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

29
Q

How is P antigen formed?

A

P is formed by B3GALNT adding a GalNAc to Pk

30
Q

Auto anti-P

A

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

31
Q

What is PCH?

A

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

32
Q

Allo anti-P

A

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

33
Q

Decreased P1 antigen is seen in…

A

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

34
Q

LKE antigen

A

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

35
Q

How is LKE antigen formed?

A

PK > P > + sialic acid = LUKE antigen

36
Q

Anti-LKE

A

Rare
IgM with some complement binding
not clinically significant

37
Q

PX2 antigen

A

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

38
Q

Anti-PX2

A

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

39
Q

What disease is Pk antigen associated with?

A

Receptor for shiga toxin causing shigella dysentery

40
Q

What disease is P antigen associated with?

A

Receptor for parvovirus