Renal 3 Flashcards
What is the mechanism of action of acetazolamide?
Inhibits carbonic anhydrase –> increased excretion Na HCO3 + diuresis + decreased total body stores of HCO3
What are the clinical uses for acetazolamide? (5)
- glaucoma
- metabolic alkalosis
- altitude sickness
- urine alkalization
- pseudotumor cerebri
What are the toxicities of acetazolamide?
–hyperchloremic metabolic acidosis
–NH3 toxicity
–paresthesias
–sulfa allergy
LM: segmental sclerosis and hyalinosis
IF: negative
EM: effacement of podocyte foot processes
diagnosis?
Focal segmental glomerulosclerosis
LM: segmental sclerosis and hyalinosis
IF: negative
EM: effacement of podocyte foot processes
diagnosis?
Focal segmental glomerulosclerosis
LM: diffuse capillary and GBM thickening
IF: granular
EM: spike and dome appearance with subepithelial deposits
Diagnosis?
Membranous nephropathy
Focal segmental glomerulosclerosis
What would we see on LM, IF, and EM?
LM: segmental sclerosis and hyalinosis
IF: negative
EM: effacement of podocyte foot processes
diagnosis?
What is the treatment for membranous nephropathy? What is the response to this treatment?
Steroids.
Poor response; my progress to chronic renal disease
LM: normal glomeruli; lipid seen in PCT cells
IF: negative
EM: effacement of podocyte foot processes
Diagnosis?
Minimal change disease
What are the possible causes/triggers of minimal change disease?
- recent infection
- immunization
- immune stimulus
- may be associated with Hodgkin lymphoma
What disease process is the nephrotic presentation of SLE?
membranous nephropathy
What is the cause of the granular IF and “spike and dome” on EM for membranous nephropathy?
subepithelial immune complex deposition
LM: congo red stain shows apple-green birefringence under polarized light
Diagnosis?
amyloidosis
Briefly describe the pathophysiology of how systemic amyloidosis causes nephrotic syndrome.
amyloid deposition in the mesangium
LM: tram-track appearance
IF: granular, subendothelial immune complex deposits
Diagnosis?
membranoproliferative glomerulonephritis
Type 1
With what co-morbidities/disease is membranoproliferative glomerulonephritis Type 1 associated?
Hep b
Hep C
May also be idiopathic
With what co-morbidities/disease is membranoproliferative glomerulonephritis Type 2 associated?
Associated with C3 nephritic factor
(stabilizes C3 convertase –> decreased serum C3 levels)
Why do we see “tram-tracking” in membranoproliferative glomerulonephritis Type 1?
GBM splitting caused by mesangial growth.
LM: mesangial expansion, GBM thickening, eosinophilic glomerulosclerosis (Kimmelstiel-Wilson lesion)
Diagnosis?
Diabetic glomerulonephropathy
Membranous nephropathy
What would you see on LM, IF, and EM?
LM: diffuse capillary and GBM thickening
IF: granular
EM: spike and dome appearance with subepithelial deposits
Diagnosis?
Minimal change disease
What would you see on LM, IF, and EM?
LM: normal glomeruli; lipid seen in PCT cells
IF: negative
EM: effacement of podocyte foot processes
Diagnosis?
- recent infection
- immunization
- immune stimulus
- may be associated with Hodgkin lymphoma
These are the potential triggers for which nephrotic syndrome?
What are the possible causes/triggers of minimal change disease?
amyloidosis
What would you see on LM?
LM: congo red stain shows apple-green birefringence under polarized light
Diagnosis?
membranoproliferative glomerulonephritis
Type 1
What would you see on LM and F?
LM: tram-track appearance
IF: granular, subendothelial immune complex deposits
Diagnosis?
Diabetic glomerulonephropathy
What would you see on LM?
LM: mesangial expansion, GBM thickening, eosinophilic glomerulosclerosis (Kimmelstiel-Wilson lesion)
Diagnosis?
How does diabetes lead to glomerulonephropathy?
nonenzymatic glycosylation of the GBM –> increased permeability and GBM thickening
nonenzymatic glycosylation of efferent arterioles –> increased GFR –> mesangial expansion
LM: mesangial proliferation
EM: mesangial immune complex deposits
IF: IgA immune complex deposits in mesangium
Diagnosis?
Ig A nephropathy
(Berger disease)
How does IgA nephropathy usually present?
Often presents with URI or acute gastroenteritis
Episodic hematuria with RBC casts
What is Alport syndrome?
A mutation in Type IV collagen –> thinning and splitting of the GBM.
Most commonly X-linked
With what symptoms is Alport syndrome associated?
glomerulonephritis
deafness
less commonly, eye problems
LM: wire-looping of capillaries
IF: granular
EM: subendothelial and sometimes intramembranous IgG immune complexes, often with C3 deposition
Diffuse proliferative glomerulonephritis
What is the most common cause of death in patients with SLE?
diffuse proliferative glomerulonephritis
What are the two most common causes of diffuse proliferative glomerulonephritis?
SLE
membranoproliferative glomerulonephritis
Cresent formation in the Bowman’s space/glomerulus on H&E/LM is indicative of what disease process?
rapidly progressive glomerulonephritis
There are multiple causes of RPGN; the clinical picture and IF can help make the specific diagnosis
H&E: cresent formation in the Bowman’s space
IF: linear
Diagnosis?
Goodpasture’s Syndrome
What is the classic presentation of Goodpasture syndrome? What is the disease process?
In Goodpasture syndrome, antibodies are made against the collagen (type IV) in the glomerular and alveolar basement membranes
presents as hematuria and hemoptysis, classically in young, adult males.
H&E: cresent formation in the Bowman’s space
IF: granular
Diagnosis?
post-streptococcal glomerulonephritis
diffuse proliferative glomerulonephritis
H&E: cresent formation in the Bowman’s space
IF: negative (pauci-immune)
Diagnosis?
Wegener granulomatosis
microscopic polyangiitis
Churg-Strauss syndrome
H&E: cresent formation in the Bowman’s space
IF: negative (pauci-immune)
c-ANCA positive
Diagnosis?
Wegener granulomatosis
H&E: cresent formation in the Bowman’s space
IF: negative (pauci-immune)
p-ANCA positive
granulomatous inflammation, eosinophilia, asthma
Diagnosis?
Churg-Strauss syndrome
H&E: cresent formation in the Bowman’s space
IF: negative (pauci-immune)
p-ANCA positive
No granulomatous inflammation, eosinophilia, or asthma
Diagnosis?
microscopic polyangiitis
LM: glomeruli enlarged and hypercellular
IF: granular, lumpy-bumpy appearance (IgG, IGM, C3 deposition along GBM and mesangium)
EM: subepithelial humps (IC)
Diagnosis?
post-streptococcal glomerulonephritis
What is the classic hx for post-streptococcal glomerulonephritis?
Peripheral and periorbital edema, dark urine, and hypertension approximately two weeks after group A ß-hemolytic streptococcal infection of the pharynx or skin (impetigo).
increased anti-DNase B titers and decreased complement levels.
What are the classic symptoms in nephritic syndromes?
azotemia
oliguria
hypertension (due to salt retention)
proteinuria (<3.5g/day)
hematuria and RBC casts in the urine
What are the symptoms of nephrolithiasis (kidney stones)?
Colicky pain that radiates to the groin
unilateral flank tenderness
hematuria
Ig A nephropathy
(Berger disease)
What would we see on LM, IF, and EM?
LM: mesangial proliferation
EM: mesangial immune complex deposits
IF: IgA immune complex deposits in mesangium
Diagnosis?
Diffuse proliferative glomerulonephritis
What would we see on LM, IF, and EM?
LM: wire-looping of capillaries
IF: granular
EM: subendothelial and sometimes intramembranous IgG immune complexes, often with C3 deposition
Goodpasture’s Syndrome
What would we see on LM and IF?
H&E: cresent formation in the Bowman’s space
IF: linear
Diagnosis?
Wegener granulomatosis
microscopic polyangiitis
Churg-Strauss syndrome
What would we see on LM and IF?
H&E: cresent formation in the Bowman’s space
IF: negative (pauci-immune)
Diagnosis?
Wegener granulomatosis
What would we see on LM and IF? How would you distinguish this diagnosis from microscopic polyangiitis or Churg-Strauss syndrome?
H&E: cresent formation in the Bowman’s space
IF: negative (pauci-immune)
c-ANCA positive
Diagnosis?
Churg-Strauss syndrome
What would you see on LM and IF?
How would you distninguish this from Wegener granulomatosis? How would you distninguish this from microscopic polyangiitis?
H&E: cresent formation in the Bowman’s space
IF: negative (pauci-immune)
p-ANCA positive
granulomatous inflammation, eosinophilia, asthma
Diagnosis?
