Blood transfusion Flashcards
How many allelic forms are present in blood cells?
3
What are the three allelic forms?
Ia, Ib, Io
Which blood group allele is recessive?
Io,
Which blood groups are present?
A, B, AB, O
Which type of antibodies is present within the blood that detects self-blood antigens?
The antibodies have immunoglobulin variable regions specific to antibodies that are not present on the self-erythrocyte.
Which type of antibody activates complement?
IgM
How are A and B antigens?
Formed by the addition of one or other sugar residue onto a common glycoprotein and fucose stem (H antigen)
What is the structure of Group O erythrocytes?
Contains neither A or B sugars- H stem is only present
Which molecule is added to the H antigen? (A group)
N-acetyl galactosamine
Which molecule is added to the H antigen? (B group)
Galactose
What is the genotype for the A antigen?
AA, OA
What is the genotype for the B antigen?
BB, OB
What are anti-antibodies?
Associate and bind onto the respective immunoglobulin molecules within the cell surface membrane, resulting in cellular agglutination
What is Rh factor?
Rhesus factor is an inherited protein located on the cell surface membrane of erythrocytes.
What Rh positive?
Presence of protein
What is Rh-negative?
Lack of protein
What is the most common Rh protein?
D
What does the D gene encode?
Encodes for the D antigen on the erythrocyte surface
What does the d gene encode?
d gene encodes for no antigens
What is the genotype of RhD negative?
dd
What is the genotype of RhD positive?
Dd DD
What are anti-D antibodies?
Synthesized by individuals unable to present RhD antigen, only after they are exposed to the antigen.
What circumstance are anti-D antibodies present?
Upon exposure to the D antigen, transfusion of RhD positive blood
RhD positive fetus
What type of antibody is anti-D?
IgG class antibodies