Membranoproliferative GN (MPGN)

- In the past, it was classified into 3 subtypes:
   (1) Type I MPGN with mesangial proliferation and basement mm duplication (MPGN [mesangial and subendothelial deposits by E/M].
   (2) Type II or DDD with varied histological pattern with/without MPGN [electron dense mesangial and intramembranous deposits by E/M.
   (3) Type III similar to type I but E/M shows mesangial, subendothelial, subepithelial and intramembranous deposits

- Recently it is classified into:
  1. MPGN type I 
  2. C3 glomerulopathy
  3. MPGN type III

- C3 glomerulopathy is an entity with glomerular deposits made mainly (or solely) from C3  
  (Predominant glomerular C3 intensity of ≥ 2 levels of  magnitude greater than any combination of IgG, IgM, IgA and C1q)

- C3 glomerulopathy include: 
  1. DDD (dense deposit disease) 
  2. C3 glomerulonephritis 
  3. Cypriot cohort (CFHR5)

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