MMP9 and systemic lupus erythematosus: In a cross-sectional study evaluating SLE patients with a priori defined cognitive dysfunction, serum MMP-9 levels were higher in the following groups: (i) patients with NPSLE manifestations (73.2 ± 46.1 ng/mL) compared to patients without (42.8 ± 26.8 ng/mL); and (ii) patients with cognitive dysfunction (80.8 ± 45.8 ng/mL) compared to those without (48.6 ± 34.2 ng/mL) [64].