C3 and systemic lupus erythematosus: Nevertheless, it is common practice to monitor complement levels to discriminate between nephritis and pre-eclampsia in SLE expecting mothers presenting new-onset proteinuria: the serum C3 and C4 levels rise in patients with pre-eclampsia, while disease flares are classically characterized by consumed C3 and C4 and raise of anti-dsDNA titres (Mok, 2001).