C5 and lobular neoplasia: The level of plasma C5a was significantly higher in patients with AAV in the active phase than that in patients with AAV in remission, patients with LN, and normal controls (75.67 ± 11.93 ng/ml versus 8.78 ± 1.12 ng/ml; P < 0.001; 75.67 ± 11.93 ng/ml versus 30.42 ± 4.07 ng/ml; P < 0.001; 75.67 ± 11.93 ng/ml versus 7.37 ± 0.90 ng/ml; P < 0.001, respectively).