How is morphology of C3 glomerulopathy?

➢ Glomerular changes in dense deposit disease and C3 GN vary from relatively subtle to severe ➢ The classic light microscopic presentation is similar to that seen in MPGN, type 1 : hypercellular glomeruli, duplicated basement membranes in capillary walls , Increased mesangial matrix. ➢ By IF microscopy : bright mesangial and glomerular capillary wall staining for C3 in both dense deposit disease and C3 GN. ➢ In dense deposit disease, C3 staining also may be seen along the tubular basement membranes ➢IgG and the early components of the classical complement pathway (C1q and C4) are usually absent in both conditions. ➢By electron microscopy, C3 GN features mesangial and subendothelial electron-dense “waxy” deposits; similar deposits also may be seen along the tubular basement membranes. ➢By contrast, in the dense deposit disease, the lamina densa and the subendothelial space of the GBM are transformed into an irregular, ribbonlike, extremely electrondense structure, resulting from the deposition of C3-containing material