HLA IN TRANSPLANTATIONAND TRANSFUSION Flashcards
what does HLA stand for?
human leukocytes antigen system
what is the HLA
major histocompatibility complex in humans
distinguishes between self and nonself
where are all MHC genes located?
short arm of chromosome 6
what HLA does class 1 consist of?
HLA A,B and C
what HLA does class 2 consist of?
DR, DP and DQ
HLA genes are inherited in a codominant mendelian fashion. What’s that?
you get both - no recessive or dominant
digits 1&2
serologically defined
digits 3&4
identify alleles
can lead to changes in amino acid sequence, but won’t change overall shape
digits 5&6
indicates silent nucleotide substitution
do not! change amino acid sequence but can change nucleotides
digits 7&8
account for polymorphism in non-coding region of the gene
useful for detecting where HLA genes have mutated
what resolution does 4 digits represent
high resolution
what does 2 digits mean
low resolution, serological
how do we screen for antibodies?
lymphocytotoxic test / cytotoxicity test
what is the cytotoxicity test procedure?
- isolate lymphocytes from coagulated blood.
either known lymphocyte and unknown antibody
or
unknown lymphocyte and known antibody - layer blood over lymph prep solution.
- spin and separate
- stain lymphocytes with dye that can only be fluorescent after cell modification
- put in well.
well contains antibodies, bind if antibody and antigen reaction recognise. - P iodide can enter cell, bind with DNA and fluoresce red.
- Higgins ink and EDTA are added. Visual aid and EDTA stops reaction
purpose of mineral oil in cytotoxicity test procedure
prevents evaporation
