C3 and systemic lupus erythematosus: Due to the presence of leukopenia, pericardial and pleural effusions, proteinuria, and hematuria SLE work-up was sent with results showing the following: +ANA titers of 1 : 2560 4+ speckled, Anti-ds-DNA positive titer 1 : 80, and AntiSmith ab positive >8, low C3 and C4 levels at <40 mg/dL and <10 mg/dL, respectively.