IgM blood systems (P)

P1PK system includes

P1, Pk, and NOR

Globoside blood group system includes

P

Globoside blood group collection includes

LKE, PX2

NOR is

A low prevalence antigen that results from a single nucleotide change in A2GALT

P group synthesis

Glycosyltransferase adds sugars to precursor substances

Enzyme responsible for encoding Pk synthesis

P1Pk (A4GALT)

Globoside responsible for converting Pk to P

B3GALT

Precursor to P1 can be

Glycosylated to type 2H chains that carry ABH antigens

Common P phenotypes

P1 and P2

P1, Pk, or P can be found on what cells

Red and white

P antigen can be found on

Platelets, epithelial cells, and fibroblasts

P and Pk antigens have been found

In plasma as glycosphingolipids or in hydrated cysts as glycoproteins

P1 antigen characteristics

Takes up to 7 years to be expressed, strength depends on race, deteriorates quickly, and exists as glycosphingolipids in blood

Anti-P1 can be seen as

Naturally occurring IgM or unnaturally occurring in a P1 individual

Recommended test to confirm anti-p1

Inhibition

Anti-p1 reacts best at

4° (cold reactive saline agglutinin)

Do you need to cross match including P1?

No;rarely causes HTR, doesn’t cause HDFN

People with hydrated cyst disease may

Form potent anti-P1 if P1 is negative

Anti-PP1Pk characteristics

IgM and IgG, reacts over wide thermal range, can be separated, causes severe HTR and HDFN

What is anti-PP1Pk associated with and why

Increase incidence of miscarriage because fibroblasts have P antigen.

Alloantibodies are mainly found in

The plasma of Pk individuals

How does Allo-anti-p compare to anti-PP1Pk?

Similar activity but it doesn’t not react with auto control, p antigen, and Pk phenotype

IgG class anti-p has been associated

With early abortions

Auto anti-p is associated with

The cold reactive IgG autoantibody in patients with Paroxysmal Cold Hemoglobinuria (PCH)

The IgG autoantibody in PCH is described as

Biphasic hemolysin

Donate landsteiner test

In vitro ab binds to RBCs in cold. When warmed it binds complement and lyses the RBCs.

Donate landsteiner test for auto anti-p

Positive (only test is reacts to)

Donald lansteiner negative control

Tube kept on heat block so it does not hemolyze

Luke antibody

Found in pts w Hodgkin’s lymphoma. IgM not reported to cause transfusion reactions or HDFN

Luke antigen positive frequency

98% (14% weak rxn, 84% normal)

All individuals with p and Pk are Luke _

Negative

Anti-P1 in a P2 person can be caused by

Parasitic infections (bovine liver fluke, tapeworm)

P system is a receptor for

UTI: E. coli

Human Parvovirus

Pk antigen is a receptor for what toxins

Shiva toxins

Pk provides some protection against

HIV infection of mononuclear cells