C3 and hydronephrosis: Multivariate logistic regression showed that ascites (odds ratio [OR]: 9.961, 95%CI: 2.215–44.802, P = 0.003), hydronephrosis (OR: 28.060, 95%CI: 2.303–341.962, P = 0.009), leukopenia (OR: 5.890, 95%CI: 1.813–19.135, P = 0.003), reduced complement C3 level (OR: 4.791, 95%CI: 1.605–14.300, P = 0.005), and elevated immunoglobin (Ig)A level (OR: 4.040, 95%CI: 1.307–12.487, P = 0.015) were independently associated with LEn.