Nephritic and nephrotic sydnromes Flashcards
Enlarged, hypercellular glomeruli on light microscopy. Granular immune deposits of IgG, IgM, and C3 in the mesangium and along GBM on immunofluorescence. Electron microscopy shows subepithelial lumps.
Acute proliferative glomerulonephritis (post-strep or post-infectious)
Possible complication of acute proliferative glomerulonephritis
Rapid progressive glomerulonephritis
Glomeruli may appear normal or have mesangial widening on light microscopy. Mesangial deposits of IgA and C3 on immunofluorescence. Electron dense deposits in mesangium on electron microscopy. Young male pt with history of similar episodes in the past.
IgA nephropathy/Berger disease
Disease characterized by anti-GBM antibody with or without lung involvement. Linear IgG and C3 deposits on immunofluorescence.
Type 1 rapidly progressive glomerulonephritis
Disease characterizes by post-infectious glomerulonephritis. Granular Ag+Ab complexes in immunofluorescence.
Type II rapidly progressive glomerulonephritis
Disease characterized by pauci-immune and ANCA-associated glomerulonephritis. No immune deposits on immunofluorescence. Most have circulating c-ANCAs or p-ANCAs.
Type III rapidly progressive glomerulonephritis
Diseases associated with type III RPGN
Wegener
Microscopic polyangiitis
Disease associated with type II RPGN
Post-infectious glomerulonephropathy
Is RPGN nephritic or nephrotic?
Nephritic
Pathogenetic type of type I RPGN
Anti-GBM
Pathogenetic type of type II RPGN
Immune-complex
Pathogenetic type of type III RPGN
Pauci-immune
RPGN type with normal serum C3, positive for anti-GBM antibody, and negative for ANCAs.
Type I RPGN
RPGN type with low to normal C3 and negative for anti-GBM antibody and ANCA.
Type II RPGN
RPGN type with normal C3, negative for anti-GBM antibody, and positive for ANCA.
Type III RPGN
Diseases associated with type I RPGN
Goodpasture’s syndrome
SLE
Vasculitis
Wegener’s granulomatosis
Henoch-Schonlein purpura
Treatment for nephritic syndrome
Plasmapheresis
Steroids
Cytotoxic agents in Goodpasture’s syndrome
Light microscopy shows renal changes dominated by crescents. Parietal epithelium with monocytes, macrophages, and fibrin strands. Obliteration of Bowman’s space and compression of glomeruli.
Nephritic syndrome
Features of nephritic syndrome
Hematuria
RBC casts
Moderate proteinuria
Variable HTN and edema
Constant finding on electron microscopy in nephritic syndrome
Rupture of GBM
Another name for hereditary nephritis
Alport syndrome
Features of Alport syndrome
Hematuria with RBC casts
Nerve deafness (cochlea)
Lens dislocation, cataracts, corneal dystrophy
Proteinuria may develop later
What is the mutation in Alport syndrome?
Abnormal type IV collagen
Irregular thickening of basement membrane alternating with thinning producing splitting and lamination of lamina densa (basket-weave) on electron microscopy. Leads to focal segmental GN and global glomerulosclerosis.
Alport syndrome - hereditary nephritis
Features of nephrotic syndrome
Massive proteinuria
Hypoalbuminemia
Anasarca
Hyperlipidemia and lipiduria
Generalized edema 2/2 increased capillary hydrostatic pressure
Nephrotic syndrome
Why are those with nephrotic syndrome susceptible to thromboembolic phenomena
Loss of antithrombin III and renal V thrombosis
Primary causes of nephrotic syndrome in children
Minimal change disease (lipoid nephrosis)
FSGS
Drugs that can cause secondary nephrotic syndrome
Penicillamine
NSAIDs
Infections that can cause secondary nephrotic syndrome
Malaria
Syphilis
HBV and HCV
HIV
Miscellaneous causes of secondary nephrotic syndrome
Bee sting
Hereditary nephritis/Alport
Autoimmune thyroiditis
Primary causes of nephrotic syndrome in adults
Membranous glomerulopathy
FSGS
Autoimmune kidney disease characterized by M-type phospholipase A-2 receptor resulting in immune complexes along subepithelial aspect of the basement membrane
Primary membranous nephropathy
Disease characterized by slow loss of GFR, normal serum creatinine, nonselective proteinuria, edema, hypoalbuminemia, and hyperlipidemia. Urine shows oval fat bodies and fatty casts. C3 and C4 are normal.
Membranous nephropathy
Light microscopy of glomerulus shows diffuse, thickened capillary walls without an increase in the number of cells. Spikes on silver methenamine stain.
Membranous nephropathy
Mechanism of light microscopy changes in membranous nephropaty
Direct action of C5b-C9 on epithelial and mesangial cells leads to capillary wall injury and protein leakage.
Accumulation of dense IgG containing deposits along subepithelial side of GBM
Electron microscopy findings in membranous nephropathy
Electron dense deposits along the epithelial side of the basement membrane and effaced foot processes
Progression of membranous nephropathy
Sclerosis of glomeruli
Rising serum creatinine
HTN
Systemic T cell dysfunction results in the production of a glomerular permeability factor that directly affect the glomerular capillary wall resulting in marked proteinuria and foot process fusion
Minimal change disease
Nephrotic syndrome associated with respiratory infections, immunizations, and atopic disorders.
Minimal change disease
Treatment for minimal change disease
Steroid
Microscopy finding in minimal change disease
Diffuse effacement of foot processes of the podocytes.
Normal light microscopy and immunofluorescence.
Nephrotic syndrome type with proximal tubule cells laden with lipid and protein.
Minimal change disease
Slit diaphragm protein genes identified as possible sites of mutation in FSGS
NPHS1 - nephrin
NPHS2 - podocin
TRPC6 - Ca channel
Focal and segmental sclerosis of glomeruli on PAS stain. Higher incidence of hematuria, decreased GFR, and HTN with massive proteinuria, non-selective
Focal segmental glomerulosclerosis
Tubular changes in HIV associated nephropathy
Striking focal dilatation of tubules filled with proteinaceous material –> tubulo-reticular inclusions within endothelial cells on EM
Microscopy with silver stain shows retraction of glomerular tuft, narrowing capillary lumens, proliferation and swelling of visceral epithelial cells, and accumulation of IC protein adsorption droplets in visceral epithelial cells.
HIV associated nephropathy (FSGS)
Alteration of GBM with proliferation of mesangial and endothelial cells with leukocyte infiltration. Can be nephrotic, combined, or non-nephrotic.
Membranoproliferative glomerulo-nephropathy
Secondary causes of MPGN
SLE
HBV and HCV
CCL
Lymphoma
General pathogenesis of type I MPGN
Both classical and alternate complement pathways
General pathogenesis of type II MPGN
Alternate complement pathway only
Light microscopy shows enlarged, hypercellular glomeruli, lobular accentuation, tram track appearance of thickened GBM, and possibly crescents.
MPGN, both type I and II
Electron microscopy findings in type I MPGN
Subendothelial electron dense deposits
Immunofluorescence findings in type I MPGN
Granular IgG and C3 deposits
Serum findings in type II MPGN
Low serum C3, factor B, and properdin
Electron microscopy findings in type II MPGN
Deposition of dense material in the lamina densa of GBM