Renal Pathology - Nephrotic Syndromes Flashcards
Nephrotic syndrome pathology (2):
- Increased GBM permeability
- Urinary loss of plasma protein
Nephrotic syndrome clinical findings (4):
- Proteinuria (> 3.5 gm/day)
- Hypoalbuminemia
- Edema
- Hyperlipidemia and lipiduria
Diseases primarily nephrotic (4):
- Membranous nephropathy
- Minimal-change disease
- Focal segmental glomerulosclerosis (FSGS)
- Membranoproliferative glomerulonephritis (MPGN)
Membranous nephropathy - pathogenesis:
Chronic, immune-complex mediated
Membranous nephropathy - light microscopy:
Diffuse thickening of glomerular capillary wall
Membranous nephropathy - IF:
Granular, IgG and C3
Membranous nephropathy - EM (3):
- Irregular dense immune-complex deposits between GBM and epithelial cells
- “Spikes and domes”
- Effaced foot processes on epithelial cells
Membranous nephropathy - clinical features (4):
- Mild proteinuria, not selective
- Hematuria
- Mild HTN
- Course is indolent
Most common cause of nephrotic disease in children:
Minimal-change disease
Minimal-change disease - light microscopy:
No change
MInimal-change disease - IF:
No Ig or complement deposits
Minimal-change disease - EM (2):
- No electron-dense deposits
- Effacement of foot processes of visceral epithelial cells
Minimal-change disease - clinical feature:
Highly selective, massive proteinuria (mostly albumin)
Minimal-change disease - treatment:
Corticosteroids
Most common cause of nephrotic syndrome:
Focal segmental glomerulosclerosis (FSGS)
FSGS is associated with (4):
- HIV
- Heroin addiction
- Sickle-cell disease
- Morbid obesity
FSGS - pathogenesis of visceral epithelial damage (3):
- Cytokines
- Genetically determined factors
- Affect components of slit diaphragm complex
FSGS - pathogenesis of hyalinosis and sclerosis:
Plasma proteins exuding through hyperpermeable areas
FSGS - light microscopy (4):
- Sclerosing of some but not all glomeruli (focal)
- Partial glomerular scarring/sclerosis (segmental)
- Affected capillary loops collapse
- Segmental hyalinosis in affected capillary walls
FSGS - IF:
IgM and C3 in sclerotic areas +/- mesangium
FSGS - EM (2):
- Diffuse effacement of foot processes in both sclerotic and nonsclerotic areas
- Focal detachment of epithelial cells and denudation of GBM
Difference from minimal-change disease (3):
- Higher incidence of hematuria, reduced GFR and HTN
- Proteinuria more often nonselective
- Poor response to corticosteroid treatment
MPGN type I - pathogenesis (2):
- Immune complexes in the glomerulus (Ags unknown)
- Activation of classical and alternative complement pathways
MPGN type II - pathogenesis:
Activation of alternative complement pathway
