C3 and systemic lupus erythematosus: Demographic data and levels of lupus immune markers including ANA titers, anti-double-stranded deoxyribonucleic acid antibodies (anti-dsDNA), complements C3 and C4, anticardiolipin (aCL) immunoglobulin (Ig) G and IgM, anti-β2 glycoprotein (β2-IgM and β2-IgG), and lupus anticoagulant (LA) antibodies were collected.