Pathoma - Renal Flashcards
Waterhouse-Friderichsen syndrome
“Adrenal insufficiency and vascular collapse due to hemorrhagic necrosis of the adrenal gland
Often associated with disseminated intravascular coagulation due to Neisseria
Nephrotic Syndrome (characteristics and names of different types)
Characteristics:
3+ protein
Hypoalbuminemia (loss of protein leads to decreased oncotic pressure in blood = edema)
Hypercoagulable state (loss of antithrombin III)
Hyperlipidemia and hypercholesterolemia (liver is trying to bulk up the blood)
Types:
- Minimal change disease
- Focal Segmental Glomerulosclerosis
- Membranous Nephropathy
- Membranoproliferative Glomerulonephritis
- Diabetes Mellitus
- Systemic Amyloidosis
Minimal Change Disease
- H&E
- Electron microscopy
- Immunofluorescence
- Immune response
Most common cause of nephrotic syndrome in kids
- Normal glomeruli on H&E
- Effacement of foot processes on EM
- Negative immunofluorescence
- Damage mediated by cytokines from T-cells
- Good response to steroids
Loss of heparin sulfate (negative charge) in the basement membrane allowing negatively charged molecules (such as albumin) to leak through and be lost in urine
Focal Segmental Glomerulosclerosis
- H&E
- Electron microscopy
- Immunofluorescence
Most common cause of nephrotic syndrome in Hispanics and African Americans
Focal (some glomeruli) segmental (involving only part of glomerulus) sclerosis on H&E
Foot process effacement on EM
Negative immunofluorescence
Poor response to steroids
Membranous Nephropathy
- H&E
- Electron microscopy
- Immunofluorescence
- Associated diseases
Most common cause of nephrotic syndrome in Caucasians
Thick glomerular basement membrane on H&E
Immune complex deposition (granular IF)
‘Spike and dome’ (subepithelial deposits) on EM
Associated with Hep B or C, solid tumors, SLE, or drugs (NSAIDs or penicillamine)
Membranoproliferative Glomerulonephritis
- H&E
- Electron microscopy
- Immunofluorescence
- Types
Can cause both nephrotic and nephritic syndrome
Proliferation of mesangial cells (‘tram track apperance’ due to proliferation separating immune complexes) on H&E
Immune complex deposition (granular IF)
Electron microscopy:
(1) Type 1 - subendothelial deposits
(2) Type 2 - intramembranous deposits
What diseases are Type I membranoproliferative glomerulonephritis associated with?
Type I - subendothelial deposits on EM
Associated with HBV and HCV
What diseases are Type II membranoproliferative glomerulonephritis associated with?
Type II - intramembranous deposits on EM
Associated with C3 nephritic factor - autoantibody that stabilizes C3 convertase, leading to over-activation of complement, inflammation, and low levels of circulating C3 (because it was all converted to C3a)
Diabetic glomerulonephropathy
- Mechanism
- H&E
High serum glucose leads to non-enzymatic glycosylation of vascular membrane resulting in hyaline arteriolosclerosis, especially affecting efferent arteriole leading to high glomerular filtration pressure.
Hyperfiltration damage leads to leaky filtration barrier and thus microalbuminuria
Progression to nephrotic syndrome characterized by Kimmelstiel-Wilson nodules on H&E (nodules of sclerosis)
Amyloidosis as a cause of nephrotic syndrome
Amyloid deposits in the mesangium
Apple-green birefringence on Congo red stain
Nephritic syndrome:
- Characteristics
- Immune reaction
- Types
Characteristics: Glomerular inflammation and bleeding Limited proteinuria (<3.5) Oliguria and azotemia Periorbital edema and HTN RBC casts
Immune-complex deposition activates complement (C5a attracts neutrophils, which mediates damage)
Types:
- Post-streptococcal glomerulonephritis
- Rapidly Progressive
- IgA nephropathy (Berger Disease)
- Alport Syndrome
Post-streptococcal glomerulonephritis
- Cause
- Presentation
- IF
- Treatment
Occurs after Group A Strep impetigo or pharyngitis (occurs with M protein virulence factor)
Presents 2-3 weeks after infection as hematuria (cola-colored urin), oliguria, hypertension, and periorbital edema
Subepithelial immune complex deposition (‘humps’)
Treatment is supportive (the deposits will usually just push their way out and self-resolve)
H&E of Rapidly progressive glomerulonephritis
Characterized by crescents in Bowman’s space (comprised of fibrin and macrophages)
Causes of Rapidly Progressive Glomerulonephritis with Linear IF
Linear IF (anti-basement antibody):
- Goodpasture’s (antibody agains type IV collagen - in lung and kidney)
Causes of Rapidly Progressive Glomerulonephritis with Granular IF
Granular IF (immune complex deposition)
- PSGN
- Diffuse proliferative glomerulonephritis (in SLE patients - ‘wire-loop’ IF appearance - usually subendothelial deposits)
