Fig. 2.
Overlap of C3G and MPGN. A cause of uncontrolled complement activation should be suspected in cases of C3 glomerulopathy (bold circle). Specific forms of C3G include C3GN, DDD, and CFHR5 nephropathy. Light microscopy identifies a diverse pattern of glomerular injury that includes MPGN. Uncontrolled complement activation has also been identified in cases of immune-complex MPGN (shaded)—these are cases of MPGN that do not fulfill current criteria for C3G. Causes of uncontrolled complement activation should be considered in an overlapping group of C3G and MPGN