Blood Bank unit 3.1

Kell antigen incidence

KEL1 = 9% of population Low

KEL2/cellano = 90% of population High

Kpa frequency

low 2%

Kpb frequency

high 99.9%

What is significant about the Kpa antigen

It is so low that detection is found in cross match/compatibility testing

Out of Jsb & Jsa, which is high frequency

Jsb ranges 80% to 100%

Kell antigen location

single glycoprotein integral to the red cell membrane

What reagents can be used against Kell Antigens

• 2-mercaptoethanol (2-ME)

• Dithiothreitol (DTT)

• 2-aminoethylisothiouronium bromide (AET)

K0 phenotype

lacks all Kell system antigens

What happens when K0 individuals get transfusions

they make anti-Ku (KEL 5)

K- k+ frequency

White 91% Black 98%

Kp (a- b+) frequency

White 97.7% Black 100%

Js (a- b+) Frequency

White 100% Black 80%

Kell Antibodies Characteristics

• IgG

• RBC stimulated

• Agglutinate best in IAT

• do not bind complement

• Clinically significant

Kx is often see in

males because it is inherited on the x chromosome

McLeod Syndrome

• RBC abnormalities

• Muscular and neurologic defects

• increased creatine kinase

Duffy Blood Group System Characteristics

• Antigens are developed at birth

• destroyed by enzymes

Duffy BGS Fya & Fyb

• Codominant alleles

• Fy (a+b+), Fy (a-b+), Fy (a+b-)

Anti-Fya and anti-Fyb antibodies

• IgG

• Do not hind complement

• Stimulated by transfusion or pregnancy

• Do not react with enzyme-treated RBCs

• Clinically significant

Fya or Fyb acts as a receptor for what to attach to the RBC

Malaria

Kidd Blood Group System Characteristics

• Jka, Jkb, and Jk3

• Most blacks (51.1%) are Jk(a+b-)

• Most Caucasians (50.3%) are Jk(a+b+)

What is present whenever Jka and Jkb are present

Jk3

Kidd null phenotypes: Jk (a-b-)

• Seen in Pacific Islands or Far East

• Might produce anti-Jk3 antibody

• RBCs are resistant to 2M urea

Kidd Antibodies/ Anti-Jka & Anti-Jkb antibodies

• IgG

• Dosage: Jk(a+b-) reacts but Jk(a+b+) is nonreactive

• may bind complement

• Appears with other antibodies when detected

• Clinically significant

• Detection is enhanced by enzymes: LISS and Polyethylene glycol (PEG)

Lutheran BGS

• 28 antigens

• Most are high incidence

• Not affected by enzymes

• Main antigens Lua and Lub (antithetical)

Lutheran Anti-Lua

• Can occur without RBC stimulation (naturally)

• mixture of IgM and IgG

• Reacts best at room temperature

• Not clinically significant

Lutheran Antibodies Anti-Lub

• rare due to high incidence of antigen

• IgG

• reacts best at AHG

• shows mixed field

• Clinically significant

Lewis Blood Group System

• 6 antigens

• Lewis antigens are found in secretions (glycoproteins) and plasma (glycolipids)

• lipids are absorbed onto the RBC membrane

• Not developed at birth, newborns are initially Le(a-b-)

Lewis Antigens

• Hh, Se, and Le genes

• le, h, and se do not produce products

• nonsecreters have no Leb substance

• if Le gene is inherited, Lea substance is produced

Lewis antibody characteristically

• Lewis antibodies are produced by Le(a-b-)

• IgM

• Not clinically significant

• agglutination at (IS), 37, and AHG

• rarely causes HDFN

I blood group system i antigen

• I and i are not antithetical

• they form on the precursor A, B, and H chains of RBCs

• Newborns have i antigen and Adults have I antigen

• i antigen converts to I antigen as a child matures

I antibodies characteristics

• Cold-reacting, IgM, and binds complement

• not clinically significant

• reactions are avoided by prewarming

• usually auto antibodies

I antibody as a compound antibody

it is found as anti-IH and has stronger agglutination with RBCs having many H sites

What diseases are correlated with Autoanti-I ?

• Mycoplasma pneumoniae

• Cold hemagglutinin disease

What diseases are correlated with Anti-i ?

• Infectious mononucleosis

• Lymphoproliferative disease

• Cold hemagglutinin disease (sometimes)

P1PK BGS

• P1, Pk and NOR

• P1 antigen is detected in plasma and hydatid cyst fluid

Globoside BGS

P and PX2

P1PK and GLOB antigens

• P1, P2, P1k, P2k, p

P1 antigens

• Red cells express P, P1 and Pk

• P1 is not developed at birth

• most common phenotype

• No antibodies

P2 antigens

• Lacks P1 antigen but expresses P and Pk

• second most common

• Anti-P1 antibody

P1k antigens

• Red cells express P1 and Pk antigens

• very rare

• Anti-P antibody

P2k antigens

• Red cells express only Pk antigens

• very rare

• Anti-P and anti-P1

p antigens

• Null phenotype of these systems

• Negative for P, P1, and Pk antigens

• very rare

• Anti-PP1Pk

Anti-P1 Antibody

• In P2 inviduals

• IGM, enhanced by enzymes, Non-RBC stimulated

• can be neutralized by P1

Autoanti-P antibody

• associated with cold paroxysmal hemoglobinuria

• IgG

• may appear in children after a viral infection

What is associated wiith Autoanti-P and its class

Donath- Landsteiner antibody: a biphasic hemolysin that binds with P1 and P2 cells at low temperatures before the complement is activated

Anti-PP1Pk antibody

• Occurs in individuals with null phenotype

• causes hemolysis in vitro

• Clinically significant

MNS BGS

• Antigens M/N and S,s/U

M and N Antigen characteristics

• Coded by glycophroin A

• M and N have different positions (1 and 5) on glycophorin A

• Shows dosage

S, s, and U

• Coded by glycophorin B

• S and s differ at positon 29, S has methionin; s has threonine

• U antigen is located near the membrane

• Absence of glycophorin B and would result in S-s-U-

Anti-M

• IgM and IgG

• rarely clinically significant

• Variable reactions on reagent pH

Anti-N

• IgM

• rarely clinically significant

• N-like antibodies found in dialysis patients from formaldehyde sterilized instruments

Anti-S, anti-s and Anti- U

• Clinically significant IgG

• Anti-U is rare

HLAs

• Found on leukocytes and tissue cells

• HLA antibodies are produced as a result of transfusion and/or pregnancy

In heritance of HLAs

• Genes that code for HLA are part of the MHC

• MHC genes are divided into 3 classes

• Individuals inherit one haplotypes from each parent

MHC gene classes

• Class 1: platelets, leukocytes nucleated cells

• Class 2: macrophages, dendritic cells, B cells

• Class 3: code for complement and cytokines