C3 and systemic lupus erythematosus: On univariate analyses, presence of disease damage (SDI ≥ 1)was significantly associated with older age, longer disease duration, neuropsychiatry lupus (NPSLE), APLS, positive LA,use oral prednisolone more than 1mg/kg daily over more than 2 weeks, and lower cumulative C3 levels (p<0.05).