SOD1 and systemic lupus erythematosus: Increased activity of malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE), MDA-protein adduct, HNE-protein adduct, superoxide dismutase (SOD), nitric oxide synthase (INOS), anti-MDA and anti-HNE antibodies were correlated in SLE patients with SLEDAI over 6 [9,16,21].