A RAPID ELISA TEST FOR DETECTION OF HUMAN PARAPROTEINS

A rapid ELISA test for detection, characterization and quantification of human paraproteins was developed. The proposed method is a sandwich ELISA, where the capture antibody is specific for a given heavy chain (gamma, alpha or mu) and the labelled antibody is specific either for kappa or for lambda light chain. Both standard and patient sera are t ested with all six possible antibody combinations. Each paraprotein pr oduces a significant increase in titre (as compared with standard) onl y when tested with the relevant pair of antibodies. This enables the d etermination of the isotype and light chain type of the paraprotein an d the evaluation of its relative quantity in patient serum. The accura cy of the assay (relative deviation) varies from 0.04 for gamma lambda to 0.19 for alpha kappa. The cut-off values for each type of polyclon al immunoglobulin were determined with 200 healthy donor sera. 103 pat ient sera were analysed. ELISA data are in good agreement with M-compo nent and other clinical data.