Immunohematology - Lecture M5: Other Blood Group Systems (P, Ii, MNSsU)

Flashcards covering the P, Ii, and MNSsU Blood Group Systems based on the lecture by Dr. Ichiro Ordaneza.

P1PK (003)

The ISBT symbol and number for the blood group system encompassing antigens $P_1$, $P$, and $P^k$.

A4GALT

The gene product of the $P1PK$ gene (located at Chromosome $22$) also known as 4-Alpha-Galactosyltransferase.

B3GALNT1

The gene product of the GLOBOSIDE gene (located at Chromosome $3$) also known as 3-Beta-N-acetylgalactosaminyltransferase.

Lactosylceramide (Gb2)

Also known as Ceramidedihexose, it is the founding substance or precursor of the P Blood Group System.

Pk antigen

The direct precursor of the Big "P" antigen, formed when Lactosylceramide is acted upon by the enzyme $A4GALT$.

P1 phenotype

The most common phenotype in adults (approx. $75\%$), consisting of $P_1$, $P$, and $P^k$ antigens.

p phenotype

A rare phenotype lacking $P$, $P_1$, and $P^k$ antigens, which can produce Anti-$PP_1P^k$.

Hydatid cyst fluid

A substance derived from Echinococcus granulosus used in the lab to neutralize Anti-$P_1$ antibodies.

Anti-PP1Pk (Anti-Tja)

A naturally occurring antibody produced by all "p" individuals, originally named after a patient (Mrs. J) with adenocarcinoma tumor cells.

Paroxysmal Cold Hemoglobinuria (PCH)

A clinical condition associated with the autoantibody Anti-$P$, where IgG attaches complement in the cold and causes lysis upon warming.

Donath-Landsteiner antibody

Often used to refer to Autoanti-$P$, as it is specifically detected by the Donath-Landsteiner Test.

Human Parvovirus B19

A virus that utilizes the "P" antigen as its receptor for entry into host cells.

I (027) and i (207)

The ISBT symbols and numbers for the Ii blood group system; these antigens are not antithetical.

IGnT

The gene product of the I gene (located at Chromosome $6$), which is N-acetyl-glucosaminyltransferase.

I antigen

The branched form of the antigen found on adult red blood cells.

i antigen

The linear form of the antigen predominant on newborns and cord blood cells.

Anti-IT

An antibody targeting the "Transition state" during the conversion of small "i" to Big "I" antigens, showing strong reactions with cord cells.

Pathologic Autoanti-I

An IgM antibody frequently produced after Mycoplasma pneumoniae infection (Walking Pneumoniae) that reacts at room temperature and below.

Cold Agglutinin Disease (CAD)

A condition where pathologic autoanti-I forms complexes with "I" antigens on RBCs in cold temperatures, potentially causing acrocyanosis.

Anti-i association

A rare antibody sometimes associated with infectious mononucleosis caused by Epstein-Barr Virus (EBV).

MNS (002)

The ISBT symbol and number for the MNSsU blood group system, with genes located on Chromosome $4$.

Glycophorin A (GPA)

The structure on which the M and N antigens are located; it is easily degraded by enzymes due to its distal position.

Glycophorin B (GPB)

The structure on which the S, s, and U antigens are located; it is less easily degraded by enzymes compared to GPA.

Dosage

The phenomenon where antibodies like Anti-M and Anti-N react more strongly with homozygous cells than heterozygous cells.

U antigen

Stands for 'Universal' antigen; it is a high-incidence antigen dependent on the inheritance of S and s.

S-s-U- phenotype

A rare phenotype found in less than $1\%$ of the Black population resulting from a deletion of the $GYPB$ gene.

En(a-) phenotype

A phenotype resulting from the deletion of the $GYPA$ gene, characterized by the absence of M and N antigens.

Mk phenotype

A 'silent gene' phenotype involving the deletion of both the $GYPA$ and $GYPB$ genes.

Anti-M

A naturally occurring antibody that is usually not clinically significant and does not bind complement; $50-80\%$ are IgG.

Anti-S and Anti-s

Clinically significant IgG antibodies that can bind complement and cause severe HTR and HDFN.