That is: Microplates pre-coated with anti-IL-2 antibody were matched with human IL-2R alpha biotinylated antibody, and the microplates pre-coated with anti-sIL-2Rα antibody were matched with human IL-2 biotinylated antibody, to detect sIL-2Rα/IL-2 complex in the serum of SLE patients and healthy controls (n=7). Here, IL2 is linked to systemic lupus erythematosus.