EUH Krakow Conference: What causes glomerulonephritis?

The Bottom Line: Membranoproliferative glomerulonephritis (MPGN) is diagnosed on the basis of a glomerular-injury pattern that is common to a heterogeneous group of diseases. Two major pathophysiological factors — the deposition of immunoglobulin and the deposition of complement in the glomerular mesangium and capillary walls — may lead to MPGN (Sethi and Fervenza, 2012).

  • The presence of immune-complex–mediated MPGN necessitates evaluation for infections, autoimmune diseases, and monoclonal gammopathy.
  • Complement-mediated MPGN is further subdivided into dense-deposit disease and C3GN, depending on the electron-microscopical findings; the presence of complement-mediated MPGN necessitates evaluation of the alternative pathway.

References: DynaMed Plus [Internet]. Ipswich (MA): EBSCO Information Services. 1995 – . Record No. 116535, “Membranoproliferative glomerulonephritis (MPGN)“; [updated 2017 Jan 25, cited 2017 June 13]; [about 15 screens].

Sethi S and Fervenza FC. “Membranoproliferative glomerulonephritis – a new look at an old entity.” New England Journal of Medicine. 2012 Mar 22; 366:1119-1131. doi: 10.1056/NEJMra1108178.

Summary: MPGN can present with any of the following (DyanMed Plus, 2017):

  • nephrotic syndrome (reported in 40%-70%)
  • nephritic syndrome (reported in 20%-30%)
  • asymptomatic proteinuria and hematuria detected incidentally (reported in 20%-30%)
  • recurrent gross hematuria (reported in 10%-20%)

Glomerulonephritis suspected in children based on urinalysis showing hematuria, cellular casts, or other evidence of nephritis

Diagnosis of MPGN requires:

  • kidney biopsy showing typical pattern on light microscopy of diffuse mesangial cell proliferation with capillary wall thickening due to deposits of immune complexes or complement factors
  • immunofluorescence and electron microscopy exam of biopsy specimen are done to determine type of MPGN
    • immunofluorescence determines if deposits are due to immune complexes and/or complement factors
    • electron microscopy determines location of the deposits (subendothelial, intramembranous, or both subendothelial and subepithelial
  • diagnosis of primary (idiopathic) MPGN made by excluding secondary causes

Differential Diagnosis:

  • C3 glomerulopathy including dense deposit disease
  • other causes of glomerulonephritis:
    • membranous nephropathy
    • acute postinfectious glomerulonephritis
    • focal segmental glomerulosclerosis
    • minimal change disease
    • lupus nephritis
    • IgA nephropathy
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