Struggling to understand the difference between adsorptions and elutions? Ruth Evans from NHS Blood and Transplant talks Suzy through investigating the patient with a panreactive antibody.
The direct antiglobulin test ascertains whether the patient has antibodies on their red cells in vivo. A positive test may be due to autoantibody or less frequently exogenous antibody (e.g. intravenous immunoglobulin, haemolytic disease of the newborn) or alloantibody on transfused cells.
In the context of transfusion, autoantibodies are considered a nuisance! Adsorption studies are done in patients with autoantibodies in order to remove the antibody and establish whether there are any additional clinically significant alloantibodies present.
Blood in people with autoantibodies is issued as “suitable for” as strictly it is not cross match compatible. “Least incompatible” blood is only used when there is insufficient time for testing to be completed. No patient should die from lack of blood.
As we record we try to ensure we are as clear as possible. The following clarifications may be useful particularly for those revising for exams:-
2:10 “c and e” refer to anti-c and anti-e
23:19 “homozygously negative for different antigens” (rather than “cells”)