Kidney nontumor
Membranoproliferative glomerulonephritis (MPGN) and complement related diseases
C1q nephropathy

Topic Completed: 2 April 2012

Minor changes: 6 February 2020

Copyright: 2002-2020,, Inc.

PubMed Search: C1q nephropathy [title]

Nikhil Sangle, M.D.
Page views in 2019: 493
Page views in 2020 to date: 179
Cite this page: Sangle N. C1q nephropathy. website. Accessed May 24th, 2020.
Definition / general
  • Heterogeneous disease (J Am Soc Nephrol 2008;19:2237) first described in 1985 (Am J Kidney Dis 1985;6:103)
  • Considered by some an independent disorder, by others a subgroup of primary focal segmental glomerular sclerosis (Clin Exp Nephrol 2009;13:263)
  • Rare; causes proteinuria that may progress to end stage renal failure; rarely presents with gross hematuria (Pediatr Nephrol 2010;25:165)
  • Teenagers and young adults, higher incidence among blacks and females
  • Presents as nephrotic syndrome, renal insufficiency or hematuria
  • Collapsing C1q nephropathy with rapid progression to end stage renal disease appears to reside in the MYH9 associated disease spectrum (Am J Kidney Dis 2010;55:e21)
  • Laboratory testing for lupus and HIV negative, normal complement levels and no evidence of infectious or autoimmune disease
Case reports
Microscopic (histologic) description
  • Focal and segmental glomerulosclerosis and minimal change disease patterns most common
  • Variable mesangial hypercellularity with increase in mesangial matrix
  • Variable segmental glomerulopathy
Microscopic (histologic) images

Images hosted on other servers:

Various images: H&E, global granular mesangial staining for C1q, EM

Increase in mesangial cellularity

Segmental sclerosis and hypercellularity

Immunofluorescence description
  • Prominent mesangial C1q deposition; also co-deposition of IgG, IgM, IgA or C3
  • Some cases overlap with IgG nephropathy (Clin Nephrol 2009;72:360)
Electron microscopy description
  • Paramesangial electron dense immune complex deposits
Differential diagnosis
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