TRANSFUSION MEDICINE Flashcards
The most important in transfusion and transplantation from age of 6 months: posses clinically significant anti-A and/or anti-B antibodies in serum.
ABO system
Is the precursor to the ABO blood group antigens
H-antigen
H-antigen deficiency is known an __ that do not express H antigen on their RBCs.
Bombay phenotype
Results from mutations in ABO that causes a lot of glycosyl transferase activity
Group O phenotype
Genes of the 33 blood group systems are:
- autosomal (except XG and XK which are X-borne)
- MIC2 (present on both X and Y chromosomes)
As H-antigen acts as precursor, its absence means the
absence of
Antigen A and B
second most important blood group system after ABO. Consists of 50 defined blood group antigens out of which only five are important.
Rhesus system
The status of Rhesus system is indicated as either
Rh-positive (D-antigen present) or Rh-negative (D-antigen absent).
normally not present in the blood of individuals with D-negative RBCs, unless the circulatory system of these individuals has been exposed to D-positive RBCs.
anti-Rh antibodies
is given against Rh immunization using anti-D lg for pregnant Rh- negative mothers who have given birth to Rh-positive child.
Prophylaxis
- first described by Landsteiner and Levine in 1927 is based on two genes: Glycophorin A and Glycophorin B.
- It is under control of an autosomal locus on chromosome 4 and also under control of a pair of co-dominant alleles LM and LN.
MNS antigen system
are usually IgM types and rarely, associated with transfusion reactions.
Anti-M and anti-N
Comprised of four pairs of allelic antigens representing single amino acid substitution in the Lutheran glycoprotein at chromosome 19. Antibodies against this blood group are rare and generally not considered clinically significant.
Lutheran system
- the third most potent immunogenic antigen after ABO and Rh system, and are defined by an immune antibody, anti-K.
- It was first noticed in the serum of Mrs. Kellacher. She reacted to the erythrocytes of her newborn infant resulting in hemolytic reactions. Since then 25 Kell antigens have been discovered.
Kell system
causes severe hemolytic disease of the fetus and newborn (HDFN) and haemolytic transfusion reactions (HTR).
Anti-K antibody