ABO Discrepancies Disclosure Objectives Importance Recognition ...
ABO Discrepancies Disclosure Objectives Importance Recognition ...
ABO Discrepancies Disclosure Objectives Importance Recognition ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
4/12/2011<br />
Reverse Grouping Problems<br />
Weak/Missing Antibodies<br />
Newborns<br />
Antibodies are not present at birth and only develop after 3<br />
to 6 months of age.<br />
Elderly<br />
Weakened antibody activity<br />
Hypogammaglobulinemia<br />
Little or no antibody production<br />
(immuno-compromised patient)<br />
NO agglutination on reverse grouping<br />
Reverse Grouping Problems<br />
Resolving Weak/Missing Antibodies<br />
Determine patient’s age and diagnosis<br />
Incubate serum testing for 15 minutes at room<br />
temperature or 18°C to enhance antibody reactions<br />
If negative, incubate serum testing at 4°C for 15<br />
minutes<br />
Reverse Grouping Problems<br />
Extra Antibodies<br />
Result of:<br />
Cold antibodies (allo- or auto-)<br />
Cold antibodies may include anti-I, H, M, N, P, Lewis<br />
Rouleaux<br />
Anti-A 1 in an A 2 or A 2 B individual<br />
Reverse Grouping Problems<br />
Resolving Extra Antibodies: Cold Alloantibodies<br />
Perform antibody identification at IS and or RT<br />
Use the pre-warm technique<br />
Incubate the serum and red cells separately at 37°C before<br />
testing<br />
Perform a cold adsorption<br />
Incubating equal amounts of red cells and serum at 4C for 30 to<br />
60 minutes and test adsorbed serum against reverse type cells<br />
Antigen type reverse cells for the offending antigen<br />
If reverse type cells are antigen positive find reverse type cells<br />
that are antigen negative and incubate with serum to resolve<br />
discrepancy.<br />
Reverse Grouping Problems<br />
Extra Antibodies: Rouleaux<br />
Result of:<br />
Abnormal concentrations of serum proteins<br />
Altered serum/protein ratios<br />
High-molecular-weight volume expanders<br />
Associated with:<br />
‣ Multiple myeloma<br />
‣ Waldenstrom’s macroglobulinemia (WM)<br />
‣ Hydroxyethyl starch (HES), dextran, etc<br />
Reverse Grouping Problems<br />
Resolution of Extra Antibodies: Rouleaux<br />
REMOVE PROTEINS!!<br />
If the forward grouping is affected, wash cells to<br />
remove protein and repeat test<br />
If the reverse grouping is affected, perform saline<br />
replacement technique (more common)<br />
Reagent cells and patient serum are centrifuged to allow<br />
antibody attachment (if present)<br />
Serum is removed and replaced by an equal volume of salinewhich<br />
disperses cells<br />
Tube is mixed, centrifuged, and re-examined for agglutination<br />
6
Change language