Harvey's Garden

Immunofluorescence

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Nephrotic syndrome

Membranous nephropathy

  • Subepithelial (aka on basement membrane) deposits of IgG and C3 (dense deposits) → spike and dome appearance

Minimal change disease

  • EM: effacement of podocyte foot processes (微不足道)

Renal amyloidosis

Nephritic syndrome

Poststreptococcal glomerulonephritis

Characteristic by granular (​lumpy-bumpy​) pattern of staining of the GBM

Membranoproliferative glomerulonephritis

Type I MPGN:

  • Electron microscopy: Characterized by the presence of discrete subendothelial electron dense deposits
  • Mesangial and occasional subepithelial deposits may also be present
  • Immunofluorescence shows IgG, IgM and C3 deposited in a granular pattern and every complement components (C1Q and C4) are often also present indicating are immune complexes pathogenesis

Type II MPGN (more diverse, more dense!)

  • Is characterised by deposition of dark, ribbon like electron dense material in the central layer of (Lamina Densa) of glomerular basement membrane
  • Immunofluorescence – C3 deposition on both sides of the basement membrane in irregular granular or linear pattern
  • C3 can also be identified in mesangium in the ring shaped aggregates

Diffuse proliferative glomerulonephritis

Diagnostics

  • ↓ Serum C3 complement levels
  • ANA, anti-dsDNA antibodies
  • LM
    • Thickening of glomerular capillaries (appear as wire loops)
    • Characterized by increased glomerular cellularity in more than half of the glomeruli
  • EM
    • An immunofluorescence pattern containing IgG, IgM, IgA and C3, C1q is highly characteristic of lupus nephritis and is referred to as a full-house (三带一对, ie, a poker hand with three of a kind 3 immunoglobulin classes and two of a kind 2 complement components).
    • The full-house pattern reflects the pathogenesis of lupus: loss of immune tolerance to self-antigens (eg, double-stranded DNA) leads to generation of polyclonal autoantibodies that form circulating immune complexes; these deposit in the glomeruli, where they cause local injury by activating the classical complement cascade.
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IgA nephropathy

Note that the pattern is that of mesangial deposition in the glomerulus.

Goodpasture syndrome

This immunofluorescence pattern shows positivity with antibody to IgG and has a smooth, diffuse, linear pattern that is characteristic for deposition of glomerular basement membrane antibody with Goodpasture syndrome. Serologic testing for anti-GBM in patient serum is often positive.

Tip

Only this one has linear appearance.

Graph View