ABO/Rh/Genetics Flashcards
What naturally occurring antibody always appears in the serum of an Rh positive individual?
None
very rarely anti-E or anti-Cw
Purpose of washing red blood cells
Eliminates serum proteins
What happens when a patient receives multiple units of compatible blood type different from their own?
Patient may show mixed cell populations
May temporarily type as Rh negative
What other reaction is interpreted as a positive reaction if using serum (not plasma)?
Hemolysis
Where are the red cell antigens found?
Surface of the red cell
Homozygous
Identical alleles are inherited at a given locus
Ex. cc
Genotype
The actual genes on the chromosome
Ex. AO
Phenotype
The expression of the genotype
Ex. A
Prozone
Excess antibody which discourages or stops the bridging between antibody-antigen complex to form agglutination
Dominant
A trait or characteristic that will be expressed even though it is on only one of a chromosome pair
Ex. A
Recessive
A gene that will not be expressed if its dominant allele is present, it will be expressed in homozygous state only
Ex. O
Cis
Alleles on the same chromosome
Ex. DCe/dce
Trans
Alleles on different chromosomes
Dce/DCe
Heterozygous
Two different alleles - one on each individual chromosomes
Ex. Fya and Fyb
Paragloboside
Precursor for H antigen
Paragloboside + fucose
H antigen (precursor for A and B)
4+ agglutination reaction
One large agglutinant
3+ agglutination reaction
Several large agglutinants
2+ agglutination reaction
small agglutination with clear backround
1+ agglutination reaction
fine agglutination with red background
Causative agent of intravascular transfusion reaction
IgM antibody that has a broad thermal range of activity
Consequence of intravascular transfusion reaction
Complement proceeding to lysis of donor RBCs (intravascular hemolysis)
Causative agent of extravascular transfusion reaction
IgG antibody
Consequence of extravascular transfusion reaction
Antigen (RBC) and antibody complex removed slowly in spleen
What is the first thing you do if you find an ABO/Rh typing discrepancy?
Repeat testing
Order of decreased in H substances
O > A2 > B > A2B > A1 >A1B > >Oh
Which blood type would be most likely to make anti-H?
A1B because it has the least H on surface. Seen as foreign
Antigen: patient RBCs
Antibody: purchased reagent
Front testing
Antigen: purchased RBCs
Antibody: patient serum
Reverse testing
Antigen: patient RBCs
Antibody: purchased reagent + potentiator
D tube testing
Antigen: patient RBCs
Antibody: none + same potentiator as D tube
Rh control tube
What antibody class is naturally occuring ABO antibodies?
IgM