Powerful tools for resolving antibody problems

Background Identifying the specificity of antibodies in a patient's plasma can be as straightforward as testing selected reagent red cells on the basis of the antibody detection results. Many investigations, however, require the use of additional methods or supplemental tests for resolution. Aims Specifics related to performance of these procedures, their interpretations and their limitations were reviewed. Discussion Gel microcolumn or solid phase methods, polyethylene glycol or low-ionic strength saline enhancement media or unenhanced tests have appropriate uses for detecting or avoiding antibody reactivity. Useful red cell treatments include enzymes or thiol compounds to destroy antigens or enhance the antigen–antibody interaction and EDTA–glycine acid or chloroquine diphosphate to remove bound IgG from autologous cells. Separating autologous red cells from transfused donor cells for phenotyping or testing with plasma or eluate is critical. Alloantibodies or autoantibodies can be removed or separated by appropriate adsorption tests. Inhibition of antibody reactivity by a known soluble blood group substance confirms specificity or neutralizes interfering reactivity. Conclusion Combined into a logical investigation, these additional tests will aid in resolution of most antibody-containing samples.