MMP9 and systemic lupus erythematosus: Among the nine analytes measured (IL-6, IL-10, IFN-γ, NGAL, MMP-9, S100A8/A9, S100B, TNF-α, and TWEAK) we found that compared with non-CI SLE patients, those with CI had significantly higher serum levels of S100A8/A9, and to a lesser extent MMP-9.