P Blood Group System

Which are the 3 KEY antigens seen in the P blood group system?

P, Pk, P1

What are the 2 common phenotypes seen in P blood group system?

P1 and P2

What antigens are on the RBC surface in P1 phenotype?

P1, P, & Pk

What antigens are on the RBC surface in P2 phenotype?

P, Pk

P1 IS ABSENT

Which antigens are present in the little p phenotype / Tja?

LACKS P1, Pk, and P

SO NO P antigens

What antibodies are seen in P2 phenotype?

Anti-P1

What antibodies are seen in the p/Tja phenotype?

Anti-P,P1,Pk

What can neutralize Anti-P1?

Soluble P1

Where are the 3 other places that P1 antigen is associated with?

1. PIGEON DROPPINGS

2. Plasma

3. Hydatid cyst fluid

Parasites

What kind of antibodies are Anti-P1?

IgM

At what temperature do IgM’s react?

Room temp or COLD TEMP

Which P blood group phenotypes will have an ABSENT P antigen?

P1k and P2k

Which phenotype makes Alloanti-P?

P1k and P2k

What kind of antibody is Alloanti-P?

IgM

Which antibody is responsible for targeting the P antigen on a patient’s OWN RBC

Autoanti-P

What else is Autoanti-P antibody known as?

Donath-Landsteiner antibody

What kind of antibody is the Donath-Landsteiner / Autoanti-P?

IgG

What is the main characteristic seen with Autoanti-P (Donath-Landsteiner) antibody?

Biphasic Hemolysin

What is seen in Biphasic Hemolysis?

Caused by Donath Landsteiner (Autoanti-P)

1. Agglutination in the cold

2. HEMOLYSIS in the warm

Paroxysmal Cold Hemoglobinuria (PCH) is associated with which antibody?

Autoanti-P / Donath Landsteiner antibody

Which antibody is associated with the little p / Tja phenotype?

Remember they have NO P antigens

Anti-P, P1, Pk

What else is the Anti-P,P1,Pk antibody known as?

Anti-Tja

What is the clinical significance of Anti-Tja?

STRONG hemolysin

PREGNANCY LOSS in women with p phenotype

How do the antibodies of the P system typically react with Enzymes?

Mostly ENHANCED