C4A and systemic lupus erythematosus: Currently, SLE was adequately controlled (Systemic Lupus Erythematosus Disease Activity Index, SLEDAI = 0, anti-dsDNA antibodies negative, C3 and C4 levels normal); medication included methylprednisolone 8 mg/day, azathioprine 50 mg/day, aspirin 50 mg/day and levothyroxine 150 μg/day.