Assay for the soluble interleukin-2 receptor by sandwich enzyme linked immunosorbent assay

A system for the detection of soluble IL-2R by sandwich enzyme linked immunosorbent assay (ELISA) was established. This assay system has good reproducibility, and was found to be specific for soluble IL-2R by examination of the binding of anti-IgM antibody or anti-IL-2R monoclonal antibody (mAb) with IgM or soluble IL-2R and inhibition by IL-2 of the binding of anti-IL-2R mAb to soluble IL-2R. The IL-2R molecules in supernatant of phytohemagglutinin-stimulated peripheral blood mononuclear cells were of 44,000-61,000 molecular weight as estimated by size of exclusion high performance liquid chromatography. The results of determinations for soluble IL-2R with a Eurogenetics kit (sandwich enzyme linked immunosorbent assay) were significantly correlated with those by the our method.