HLA Antibodies Flashcards
where do HLA antibodies result from?
exposure to non-self HLA antigens (not naturally occurring such as ABO antibodies)
the most common exposures to HLA antigens are through:
blood transfusion
pregnancy
previous transplant/tissue
Bw4 frequency in Canadian popl’n
73%
Bw6 frequency in Canadian popl’n
83%
why are HLA Abs important
- need to detect them and define so crossmatch results can be interpreted and predicted
- antibody screening performed on all potential transplant recipients and repeated while they are waiting for transplant
=> must be repeated following any potential immunizing event like transfusions
parts of an antigen molecule which contact the Ag binding site of Ab or T-cell receptor
epitope
define allo-epitopes
epitopes that differ among individual members of the same species
cross-reactive epitopes
HLA Abs that react with more than one gene/allele have shaed cross-reactive epitopes
CREG
as a result of this, pts can make multiple Abs from an exposure to one mis-matched antigen
cross-reactivity
two types of epitopes relevant to HLA antigens
public - CREG
privae - on one single gene product
an example of a public epitope
Bw4/Bw6
Bw4 freq in Canadian popln
73%
Bw6 freq in Canadian popln
83%
shared ____ _____ sequences between antigens can offe protection between mismatches
amino acids
T or F. When a donor has HLA-A2 and pt does not, the recipient can only make anti-A2
F! can also make antibodies to antigens that share the same epitope as A2
