C3 and thrombotic microangiopathy: To do so, we considered qualitative variables, mostly histopathological (acute tubular necrosis, mesangial hypercellularity, endocapillary hypercellularity, focal segmental glomerulosclerosis, crescent, interstitial fibrosis >25%, interstitial infiltrate, presence of ischemic glomeruli, arteriolar hyalinosis, fibro-intimal thickening, thrombotic microangiopathy, double contour, C3 deposit, and IgA parietal deposit) and intrinsic AKI occurrence (without confounding factor), along with clinical quantitative variables (urinary protein-to-creatinine ratio and preexisting eGFR).