C3 and Atrophy: As shown in Table 3, there were no significant differences in the pathological characteristics of the Oxford classification of renal pathological changes between the serum C3 decreased group and the normal C3 group: mesangial proliferation, endothelial-cell proliferation, segmental glomerulosclerosis, tubular atrophy, and/or interstitial fibrosis, and crescent body proportion (P ≥ 0.05).