Bb lec Flashcards
Found and soluble in plasma and saliva
Lewis
“Plasma
antigen”
Lewis
Expression of the Lewis antigens are influenced by
Hh and Sese antigens
is weak during pregnancy - Mothers
who are Le(a-b+), may be Le(a-b-)
Lewis
When was Lewis first discovered?
1946
Agglutinated RBCs from about 25% of English people
Lewis
When was Anti-Leb discovered?
1948
Le genes (Le/FUT3) are located at
short arm of chromosome 19p13.3
Le gene is linked to
Se and H genes
The gene does not actually code for the production of Lewis antigens but rather produce specific
L-fucosyltransferase to type 1 precursor substance
The system depends on 3 genes to produce the Lewis antigen
H, Se, Le genes
There are two alleles at the Lewis locus:
Le and le genes
There are two alleles at the secretor locus:
Se and se genes
Development of Lewis antigen structure begins in
first week after birth and may continue for six years
Also found on lymphocytes and platelets
Lewis antigens
-Lea substance is secreted regardless of secretor status
-Le gene adds “L-fucose” to the N- acetylglucosamine of the type 1 precursor substance to form the Lea antigen
Le(a+b-)
Le gene adds “L-fucose” to the N- acetylglucosamine, and H gene adds “L-fucose” to galactose of the precursor substance forming the Leb antigen
Le(a-b+)
Lewis antigens are resistant to treatment by enzymes
(Ficin and Papain), Dithiothreitol, and Glycine-acid EDTA
IgM, Naturally occuring
Lewis antibodies
Reacts at immediate spin
Lewis antibodies
Binds complement, and triggers in-vitro hemolysis
Lewis antibodies
(History) The antibody Anti-K was first identified in the serum of Mrs. Kelleher. It reacted with the RBCs of her newborn infant, her older daughter, and her husband. Discovery by Robin Coombs
1946
Kpa antigen and the null phenotype (Ko) were first described in
1957
Jsa were first described, named after the first producer
John Sutter
The low-incidence antigen of Kell
K24
The Kel gene is found on chromosome
7q33/34
The different Kell antigens are due to
single base mutations that results to amino acid substitutions
Member of Neprilysin family
Kell
The Kell antigens are located on a
type II glycoprotein with 731 amino acids
The glycoprotein is linked with XK protein by a disulfide bond at
Cys72
The glycoprotein is linked with XK glycoprotein by a disulfide bond at
Cys347
Found only on RBCs
Kell antigens
Appears on fetal red cells earlier than Rh proteins
Kell antigens
Kell glycoprotein has been characterized as a _________which is central to zinc binding and catalytic activity
Zinc endopeptidase
Very immunogenic (second only to D)
K antigen
Detected to as early as 7 weeks
k
Gene encoding for the antigen is associated with suppression of other Kell antigens
Kpa
Can be detected on fetal RBCs as early as 10 weeks gestation and is fully developed at birth
K
Found in 20% of blacks
Jsa
A patient’s red cells lacks the entire Kell glycoprotein, therefore, no Kell antigens
Kell null phenotype
Who identified Kell null phenotype
Bruce Chown, Marion Lewis, and Kiroko Kaita in 1957
The most encountered antibody next to ABO and Rh
Anti-K
Associated with severe HTRs and severe HDFN
Anti-K
Patients should receive antigen-negative blood
Anti-K
Are not commonly detected because individuals who lack these high-incidence antigens are scarce
Anti-Kpa, Anti-Kpb, Anti-Kpc, Anti-Jsa, Anti-Jsb
This antigens are only found in asians
Kpc
Found in erythroid tissues, brain, lymphoid organs, heart, skeletal muscle
Kx
The XK gene that encodes for the Xk protein is independent to KEL gene and found in the
short arm of chromosome Xp21.1
Kx antigens present on all RBCs except those of the
Mcleod phenotype
Who described Mcleod phenotype
Allen and his coworkers
Rare and are common in males via inheritance of X- linked through a carrier mother
Mcleod phenotype
The McLeod phenotype RBC lacks ___ and ___, with decreased expression of other Kell antigens
Kx and Km
a neuroacanthocytosis syndrome
Mcleod syndrom
Acanthocytosis, Reticulocytosis, Bilirubinemia, Low haptoglobin, and Splenomegaly
Mcleod syndrome
From a multiply transfused hemophiliac who in 1950 was found out to produce antibodies against an antigen named “Fya”
Duffy
They reported that majority of the African americans tested were Fy (a- b-). The gene responsible for such result was “Fy” - the gene is rare in whites
Sanger and colleagues in 1955
The Duffy genes is located at what chromosome
Chromosome 1
There are three alleles at the Fy locus
Fya, Fyb, Fy
a major allele in blacks
Fy
Can be detected at 6 weeks gestation and are fully developed at birth
Duffy antigens
Found in other body tissues (brain, Colon, Endothelium, Lungs, Spleen, Thyroid, Thymus, Kidneys)
Duffy antigens
Duffy Antigens reside on
Glycoprotein of 336 amino acids
a member of the superfamily of chemokine receptors
Duffy glycoproteins
Enhanced in a low ionic strength medium
Duffy antibodies
The antithetical partner of Jka was found in
1953
present on RBCs positive for Jka
or Jkb
Jk3
significant cause of Hemolytic transfusion reactions
Kidd antibodies
lacks the 3 antigens, common in Filipinos, Chinese, Japanese and Indonesians
Jk(a-b-)
Kidd resist lysis in
2M Urea
Both are well developed at birth
Jka and Jkb
___ can be detected on fetal RBCs at 11 weeks gestation while ___ can be detected at 7 weeksgestation
Jka; Jkb
The antigens are not found on other blood cells
Kidd antigens
Weak and demonstrates dosage (reacts strongly with RBCs with double dose antigen)
Kidd antibodies
Kidd antibody reactivity can be enhanced by using
LISS or PEG
Reactivity is enhanced by enzyme pretreatment of the RBCs
Anti-Jk3
Found in combination with other antibodies
Anti-Jka and Anti-Jkb
associated with both immediate and delayed HTRs and mild HDFN
Anti-Jk3
Who discovered “Ii” blood group
Weiner and his coworkers in 1956
The antigen for that agglutinin is “I” for
Individuality
A branched carbohydrate
I
Linear carbohydrate
i
I and i are both formed due to
activity of glycosyl transferase
Expressed in a reciprocal relationship
I and i
Infant RBCs are rich in
i
During the first 18 months of life, the
quantity of “i”
Decreases
adults that retains their “i” antigen
Adult-i
are precursor for the synthesis of
ABO and Lewis antigens
I and i
“i”antigen activity is defined by atleast two repeating ___________ in linear form
N-acetyllactosamine units
found on chromosome 6p24
IGnt gene (GCNT2)
Encodes the ___________ that adds N- Acetylglucosamine (G1cNAc) to form the branches
N-acetylglucosaminyltransferase
Increased “i” antigen expression is seen in
Acute Leukemia
Hypoplastic anemia
Megaloblastic anemia
Sideroblastic anemia
Thalassemia
Sickle cell disease
Paroxysmal hemoglobinuria
Chronic hemolytic anemia
Membranes of leukocytes and platelets
Ii antigens
Also found in serum, saliva, human milk, amniotic fluid, urine, and ovarian cyst fluid
Ii antigens
Common autoantibody found in virtually all sera
Anti-I
Tested at 4C and with enzyme treated RBCs
Anti-I
Reacts with adult and cord RBCs at room temperature and at 4C
Pathogenic autoanti-I
Exist as IgG or IgM in the serum of most Adult-i individuals
Alloanti-I
Production can be stimulated by microorganisms carrying I-like antigen
Anti-I
Detected by polyspecific AHG reagent
Anti-I
a rare antibody that gives strong reactions with cord RBCs and adult-i RBCs
Autoanti-i
Is a strong IgM agglutinin with higher titers and a broad thermal range of activity (may reach 30-32C)
Pathogenic autoanti-I
not associated with in- vivo RBC destruction
A benign antibody
Some are associated with Infectious mononucleosis and lymphoproliferative disorders
Anti-i
IgG types are rare but are associated with HDFN
Anti-i
P1 and Pk are assigned to
P1PK blood group system (003)
P is assigned to
Globoside blood group system (028)
LKE and PX2 are assigned to
Globoside collection (209)
Via injection of human RBCs to rabbits to
produced new antibodies
P blood group
In 1951, Levine and colleagues described Anti-Tja which is now known as _____
anti-PP1Pk
P+ became “__” and P became __”, the rare P null became “__”
P1; P2; p
described the antigen Pk
Matson and coworker in 1959
P1 describes RBCs that react with
Anti-P1 and Anti-P
P2 describes RBCs that do not react with
Anti-P1 but reacts with Anti-P
“p” phenotypes do not react with
Anti-P1, Anti- P, or Anti-Pk
Common in Japan, North Sweden, and in Ohio
p, P1k, and P2k
P1k phenotypes reacts with
Anti-P1 and Anti-Pk but not with Anti-P
P2k phenotypes reacts with
Anti-Pk but do not react with Anti-P1 or Anti-P
located on chromosome 22q13.2 encodes the 4-a-galactosyltransferase
P1PK gene (A4GALT)
located on chromosome 3q25 encodes the 3-B-N- acetylgalactosaminyltransferase
Globoside gene (B3GALNT1)
P antigens is synthesized by
glycosyltransferases
can be found on platelets, epithelial cells, and fibroblasts
P
have been found in plasma as glycosphingolipids and glycoproteins in hydatid cyst fluid
P and Pk
Antigen strength varies: From inheritance to Race
P1 antigen
Poorly expressed at birth (may even take 7years for full expression)
P1 antigen
Deteriorates rapidly on storage
P1 antigen
infected with Echinococcus granulosus worms led to the discovery of P1 and Pk substance in hydatid cyst fluid
anti-P1
have also been found in patients with Fascioliasis (bovine liver fluke disease)
Strong antibodies to P1
The common precursor of P antigens
“Lactosylceramide” (Gb2, Ceramide dihexose, or CDH)
Pk synthesis is carried out by
4-α- galactosyltransferase (Gb3, Pk synthase)
P synthesis formation is carried out
3-β-N- acetylgalactosaminyltransferase (Gb4 synthase)
described an antibody in the serum of a Hodgkin’s lymphoma patient in 1965
Tippett and colleagues
Group under P Blood group since the antibody reacted in all RBCs except 2% of P1 and P2 phenotypes
Luke Antigens (LKE)
All p and Pk phenotypes are
Luke(-)
Common, naturally occurring IgM antibody in the serum of P1(-) individuals
Anti-P1
Formerly “Anti-Tja”
Anti-PP1Pk
A component of anti-PP1Pk in “p” individuals
Alloanti-P
IgMs that reacts at room temperature
Anti-LKE
Poorly developed on fetal RBCs
Anti-P1
May cause in-vivo RBC destruction, immediate or delayed HTRs
Anti-P1
Reaction varies especially if old RBCs are used.
Anti-P1
Reacts over a wide thermal range and bind complement
Anti-PP1Pk
The antibodies had cytotoxic properties that may have helped prevent metastatic growth post surgery
Anti-PP1Pk
Can be separated by adsorption
Anti-PP1Pk
Produced by “p” individuals early in life without RBC sensitization and reacts with all RBCs except those of the “p” phenotype
Anti-PP1Pk
Produced by “p” individuals early in life without RBC sensitization and reacts with all RBCs except those of the “p” phenotype
Anti-PP1Pk
Naturally occurring in the sera of Pk individuals
Alloanti-P
Bga antigen = ____
Bgb antigen = ____
Bgc antigen = ____
HLA-B7
HLA-B17
HLA-A28
