C4A and lobular neoplasia: The patients with proliferative LN were less commonly positive for anti-U1RNP Ab (48.7% vs 77.8%, p = 0.020) and more commonly positive for anti-dsDNA Ab (88.0% vs 50.0%, p < 0.001), and more commonly had low C3 (94.0% vs 61.1%, p < 0.001) and low C4 (79.3% vs 50.0%, p = 0.015), higher creatinine level (1.13 ± 0.79 mg/dL vs 0.70 ± 0.26 mg/dL, p < 0.001), and lower GFR (83.2 ± 37.0 mL/min/1.73 m2 vs 105.1 ± 23.8 mL/min/1.73 m2, p = 0.002).