Intermediate Antibody Identification Flashcards
When should selected cell panels be performed?
use when more cells are needed to prove an antibody (3 pos cells and 3 neg cells) or when a specific antibody has not been excluded or ruled out. Proving cells can be homo or heterozygous; excluding cells must be negative for the suspected antibody but homozygously positive for the antigen you are excluding
When should pre-warm testing be used?
use when a suspected cold auto or allo antibody (IgM) has been identified and you want to eliminate its reactivity so it doesnt interfere with other testing; can be used during ABID or compatibility testing. REMEMBER; you must identify it and prove it is clinically insignificant before you can eliminate it
How do you preform the prewarm technique?
prewarm serum and cells in separate tubes then add serum to cells. incubate at 37C for 30-60 minutes and wash with warm saline three times. add AHG. all possible IgM will get washed out. dont use liss or peg because you dont want to enhance IgMs.
if you then get a negative result report as ‘cold aut/alloantibody; give XM compatible blood using prewarm technique
When would you use an enzyme treated panel?
use when you suspect multiple antibodies and you want to eliminate some reactivity so you can see what other reactivity is is still present; or can be used to enhance weak reactivity (like anti-Jka showing dosage)
When should neutralization be used?
use when working with either a Lewis, P1, or Chido antibodies. these highish frequency antibodies may mask underlying reactivity of other clinically significant antibodies. can also be used to prove the Lewis. P1, or Chido antibodies.
must run with a saline control
When should adsorptions be preformed ?
When needed to remove a cold or warm autoantibody to see if there are underlying allantibodies present. Can also be used to remove high frequency alloantibodies like anti-k or Kpb. All panel cells and AC will be positive.
Antibodies are removed by adding RBCs with the target Ag, and allowing Ab to bind to the Ag during incubation.
What are three types of adsorption?
Auto- remove autoantibody by incubating patients serum with patients own cells. Cannot be done if patient was recently transfused or HCT is too low
Homologous - use of donor cells whose phenotype is same as patient - performed when HCT of patient is too low. Can also be used to remove a high frequency antibody to detect underlying allos.
Differential - used when patient has been recently transfused or a positive DAT (both would prevent patient being phenotyped)
When should you use an elution technique?
to investigate a positive DAT. this procedure allows you to remove the antibody coating the cells and identify that antibody.
wash cells to remove unbound Ab. dissociate antibody from cell surface. techniques release, concentrate, and purify antibody by changing attractive forces between antigen-antibody or structure of RBC surface.
Antibody is freed into supernatant (eluate) and tested against panel of cells.
When should a titration be performed?
used during prenatal testing when the mother has a significant Ab. Titrations can monitor the progression of HDFN by observation of a rise in titer. this procedure is also used to prove/identify HTLA Ab.
procedure endpoint is with a 1+ reaction
When should DTT/2ME/AET be used?
this procedure is a treatment to the test cells to help identify HTLA antibodies and any underlying alloantibodies in the serum. these chemicals destroy many HTLA antigens and Kell and Lutheran. By eliminating the reactivity to these ag, underlying antibodies can be detected.
When would a cell separation be used?
Performed when patient has been recently transfused. Separation of donor cells from patient reticulocytes. prevents false typing results.
When would EGA/CDP be used?
its used when a patient needs to be antigen typed but their cells have a positive DAT. the procedure removes the Ab coating the cells, leaving the cells clean and capable of being ag-typed at the ahg phase. the positive DAT will otherwise cause false AHG typings if not treated first.
