KELL,MNS

MNS Blood Group System

ISBT System Number

002

MNS Blood Group System

Effect of Enzymes

DESTROYED

How many antigens are included in the MNS system

46 antigens

Discovered the anti-M and anti-N ab

Landsteiner and Levine

discovered S

Walsh and Montgomery:

M+ N+ →

weaker reaction/agglutination

M+ N- →

Higher reaction

consists of 131 amino acids, with 72 outside the cell membrane

GPA

M and N antigens are antithetical and differ in their amino acids at

positions 1 and 5

The major RBC sialic

Glycophorin A (GPA): M and N Antigens

Glycophorin B (GPB):

S, s and U antigens

S and s antigens differ at

position 29

is located near the membrane and is always present when S or s is inherited

U antigen

- less easily degraded by enzymes because the antigens are located farther down the glycoprotein

S and s antigens

● They do not bind complement regardless of their immunoglobulin class, and they do not react with enzyme treated RBCs.

● It rarely causes HTRs, decreased red cell survival, or HDFN.

● More common in children than in adults

Anti-M

Particularly common in patients with bacterial infections

Anti-M

have been found more frequently in dialysis patients exposed to formaldehyd esterilized dialyzer membranes

Anti-N

● Clinically significant IgG antibodies that can cause decreased red cell survival and HDFN.

● They may bind complement, and they have been implicated in severe HTRs with hemoglobinuria

Anti-S, Anti-s, and Anti-U

● Typically IgG

● Has been reported to cause severe and fatal HTRs and HDFN.

U phenotype

is resistant to enzyme treatment

U antigen

● may serve as the receptor by which certain pyelonephrogenic strains of E.coli gain entry to the urinary tract

GPAM

CA that uses GPA and GPB for cell invasion.

Plasmodium falciparum

Anti-K is Identified in

1964 in the serum of Mrs. Kelleher

Kx ISBT number

019 and symbol XK

Kx antigen is found in

Erythroid tissues or RBCs (as well as other tissues like brain, lymphoid organs, heart, skeletal muscle)

Kell Blood Group Antigens are found only on

RBCs

- detected on fetal RBCs as early as 10 weeks

● Well developed at birth

K-antigen

- detected at 7 weeks

k antigen

(aka Cellano)

k antigen

Other Antigens

● Kpa, Kpb, and Kpc, Jsa, Jsb Antigens

Depressed reactivity of anti-K is observed in some

LISS reagents

● It is a separate blood group, but it is related to the Kell blood group

The Kx Antigen

Kx is present on all RBCs except those of the rare

McLeod phenotype

phenotype RBCs have increased Kx antigen

K0 and Kmod

RBCs lack expression of a Kell antigens

Ko

Immunized individuals with Ko phenotype typically make an antibody called

Anti-Ku (K5)

RBCs lack Kx and another high-prevalence antigen, Km and have marked depression of all Kell antigens

McLeod phenotype

Decreased deformability and reduced in vivo survival. Instead of flexibly entering the small vessels they disintegrate

Acanthocytic

McLeod phenotype is Associated with

Chronic Granulomatous Disease (CDG

is characterized by the inability of phagocytes to make NADH

(nicotinamide adenine dinucleotide oxidase), an enzyme important in generating H2,O2, which is used to kill ingested bacteria.

CGD

Develop a slow, progressive form of muscular dystrophy (muscle will shrink) between ages 40 and 50 years

McLeod individuals