IL2 and systemic lupus erythematosus: However, the mixed solid-phase sandwich ELISA system, both solid-phase anti-sIL-2Rα antibody matched with labeled anti-IL-2 antibody and solid-phase anti-IL-2 antibody matched with labeled anti-sIL-2Rα antibody, can detection signal of heterodimeric sIL-2Rα/IL-2 complex in the serum of SLE patients, but not in the serum from healthy volunteers.