According to subgroup analysis with SLE disease activity index (SLEDAI) score, patients with active disease (N = 34) had elevated serum levels of MASP2 as compared to that in less active (N = 27) patients (12 595.28 ± 770.33 vs 11 771.20 ± 506.43 pg/mL, P < .001). Here, MASP2 is linked to systemic lupus erythematosus.