H ABO Flashcards
BAND 3
Diego
GLYCOPHORIN A & B
(tallest rbc membrane protein)
MNSS
GLYCOLIPIDS
ABO LEWIS
POLYPEPTIDES
Rh glycoprotein
registered blood group systems up to date
36
ISBT
International Society of Blood Transfusion.
ABO blood group antigen would not exist without…
H gene
• Discovered the ABO blood groups in 1901
Paved the way for the study of immunohematology and blood transfusion medicine
• First person who performed ABO forward and reverse blood grouping
KARL LANSDSTEINER
What is the Landsteiner law?
If an antigen is present on the red blood cells, the corresponding antibody will not be present in the plasma. This prevents the body from attacking its own blood cells.
A blood type
A antigen
Anti B antibody
B blood type
B antigen
Anti A antibody
O blood type
No AB antigen
Anti A and Anti B antibody
Determines the antigens present on the red cell surface
• Make use of______ as reagent
• Sample used is______
FORWARD TYPING
Front type / shift to the right typing / Direct cell typing
ANTISERA
red blood cells
To determine what are the antibodies that could be present on the patient’s sample.
• Sample =______
Reagent=______
REVERSE TYPING
Back type / shift to the left typing / Indirect cell typing
Plasma
Make use of KNOWN RED CELLS
FREQUENCY DISTRIBUTIONS OF ABO PHENOTYPES
O>A>B>AB
_______, 1924
Multiple allele theory
Bernstein
Antibodies of O blood type
IgG
ABO cannot be expressed in the red cell if there is no_______
ABO could not be expressed in the secretion if there is a lack of_______
Hh antigen/gene.
secretor (Se) gene.
THE PRECURSOR SUBSTANCE
The inheritance of ABO gene is not actually directly going to produce an antigen but rather it is mainly going to produce a specific enzyme in which they are termed as….
GLYCOSYL TRANSFERASES.
an oligosaccharide chain attached to a protein or lipid molecule basic precursor substance of the A, B and H antigens.
PARAGLOBOSIDE
Basic precursor substance of ABH
Paragloboside
paragloboside will be converted into ABO antigen by the addition of a specific sugar made possible by the enzyme (_______) that is produced by the gene.
glycosyltransferases
enzyme produced by the gene
transfer sugar molecules on a precursor
substance in order to make it a specific ABO antigen and that precursor
substance is known as PARAGLOBOSIDE.
glycosyltransferases
TYPE 1 vs TYPE 2 PRECURSOR SUBSTANCE
seen on secretions (plasma, saliva) & body fluids
The precursor substance that is expressed on the red cell surface is type 2 precursor substance. seen on red cell membrane
Type 1: Body Fluids and Secretions
Linkage
B1 → 3 linkage
Type 2: Red Blood Cells*
Linkage
B1-4 linkage
H gene is closely linked to______, in which they are in the same loci found in Chromosome____
• The alleles of H gene is H and h
“h” - the recessive allele
“H” - dominant allele
Se gene
19
H antigen
Gene Product:
Immunodominant sugar (terminal sugar):
Alpha-2-L-fucosyltransferase
L-fucose
If you have inherited a double dose of the amorph allele of h gene(hh)= no secretion of the…
alpha-2-L-fucosyltransferase
ABO chromosome
9
A antigen
Gene Product:
Immunodominant sugar
Alpha-3-N-acetylgalactosaminyltransferase
N-acetyl-D-galactosamine
B antigen
Gene Product:
Immunodominant sugar:
Alpha-3-D-galactosyltransferase
D-galactose (Gal)
• For ABO/ABH antigens to be expressed in secretion you need to inherit the..
secretor genes
Secretor genes
Gene product:
Immunodominant sugar:
particular paragloboside:
Alpha-2-L-fucosyltransferase
L-fucose
type 1
SECRETOR GENES
SECRETOR
NON-SECRETOR
(SeSe or Sese)
(sese)
ANTIGEN LOCATION
It could also be found in other parts of the body such as:
RBCS
Endothelial cells
Platelets
Lymphocytes
Epithelial cells
Only_____ can be performed in reverse typing.
ABO
Anti-AB
IgG
Forward typing only on newborns
Why?
Titers of ABO ab at birth are very low until the baby reaches 3-6 months of age
Ab production peaks at…
5 - 10 years until adulthood
Identify antigens present on RBC
Reagent: Antibodies
Forward typing
Identify antibodies in plasma
Reagent: RBC w/ either A or B antigens
Reverse Typing
Dye
Anti A -
Anti B -
Bromthymol blue [blue Angel]
Acriflavine yellow (yellow Bird)
Gel method
Utilizes a gel card which contains 6 tubes
gels are also incorporated with the reagents
First 3 tubes - contains reagents that has;
Anti A
Anti B
RH antibodies
PRINCIPLE of gel method
If there is any agglutination reaction, the cell with the antibody that has reacted to it is going to be trapped along the gel and could not go at the bottom of the gel if there is any agglutination reaction.
2 types of precursor substances:
type 1 & type 2
TYPE 1
Found in the____
: beta 1 → 3 linkage between…
secretions
galactose and N-acetylglucosamine.
TYPE 2
Found in the…
Classified because of the linkage of terminal galactose with the preceding sugar and that is the N-acetylglucosamine.
red cell membrane
Type 2
The 1st carbon of the terminal Galactose on the precursor substance is attached to the 4th carbon of N-acetylglucosamine in a beta 1 → 4 linkage.
This is now a_____
Immunodominant sugar:_____
paragloboside/precursor substance
Galactose
