Pathology of C3 Glomerulonephritis

ABSTRACT

C3 glomerulonephritis (C3GN) is a recently described entity that shows a glomerulonephritis on light microscopy, bright C3 staining and the absence of C1q, C4, and immunoglobulins on immunofluorescence microscopy and mesangial and/or subendothelial electron-dense deposits on electron microscopy. The term 'C3 glomerulopathy' is often used to include C3GN and dense deposit disease (DDD), CFHR5 nephropathy, those of which result from dysregulation of the alternative pathway of complement. C3GN shares some aspects of atypical hemolytic uremic syndrome, MPGN, late stage of post infectious glomerulonephritis and other glomerulonephrtis. When C3GN is considered, measurement of serum complement proteins including C3, CFH, CFI, CFB and testing for the presence of C3 nephritic factor, anti-factor H autoantibodies are necessary. To screening for mutations, genes that encode complement regulators should be evaluated. This disorder equally affected all ages, both genders, and typically presented with hematuria and proteinuria. In both the short and long term, renal function remained stable in the majority of patients.