Sethi et al1 recently described an entity called C4 glomerulopathy, which is defined as bright C4d staining with no or minimal C3 or immunoglobulin deposits on immunofuorescence analysis. C4d is representative of the lectin and classic pathways of the complement system. In the cascade, after C4d is cleaved from C4b, the covalent bond between C4d and the tissue persists for a much longer time than other parts of complement elements and antibodies.2 Espinosa et al3 reported a case of immunglobulin A nephropathy in which a kidney biopsy was repeated after 12 years; the second biopsy revealed that mesangial C4d staining was still evident.