Patients with musculoskeletal and cutaneous manifestations displayed lower MBL levels compared to those with neuropsychiatric SLE (NPSLE) (P = 0.002), carditis (P = 0.002), serositis (P = 0.005), nephritis (P = 0.0009) and pneumonitis (P = 0.001). Here, MBL2 is linked to nephritis.