Non-inflammatory Glomerular Disease

Question 0

4 complications of nephrotic syndromes?

Answer 0

Edema.
Hypercoagulability.
Increased incidence of infection.
Accelerated atherosclerosis.

Question 1

4 aspects that define a nephrOTIC syndrome?

Answer 1

Proteinuria (high, >3.5g/24hr) - important.
Hypoproteinemia.
Edema.
Hyperlipidemia.

Question 2

4 compartments to look at when analyzing a renal biopsy?

Answer 2

Glomeruli
Tubules
Interstitial compartment
Blood vessels

Question 3

What does segmental vs. global refer to when talking about kidney biopsy findings?

Answer 3

Within one glomerulus, how much is affected: segmental = a small amount.
Global = whole glomerulus is involved

Question 4

What does focal vs. diffuse refer to when describing renal biopsy findings?

Answer 4

Focal is < 50% of glomeruli are affected.

Diffuse is > 50% of glomeruli are affected.

Question 5

In miminal change disease, where do you see the change in renal biopsy?

Answer 5

There will be podocyte foot process effacement visible on EM.

Question 6

Etiologies of minimal change disease?

Answer 6

primary - unknown

Secondary: NSAIDs, neoplasms (eg. lymphomas)

Question 7

Treatment / natural history of minimal change disease?

Answer 7

Corticosteroids induce remission in 90-95% of cases.
Then 1/3 never relapse, 1/3 occasionally relapse, and 1/3 frequently relapse.
(often in children, if this is suspected, steroids are given without biopsy to see if that makes it better)

Question 8

Some parts of some glomeruli have too much PAS-stainable stuff.
There’s no inflammation.
This could refer to the histologic findings of what syndrome?

Answer 8

Focal segmental glomerulosclerosis (FSGS)

Question 9

What does immunofluorescence in focal segmental glomerulosclerosis (FSGS) show?

Answer 9

Some accumulation of IgM and C3… but it’s very mild compared to the immune complex-related diseases.

Question 10

What does EM of FSGS show?

Answer 10

Podocyte foot process effacement.
No electron-dense deposits.
Collapse of capillary loops with accumulation of “hyalin”… (wouldn’t worry about this last one too much)

Question 11

What cell type is particularly unhappy in FSGS?

How does this affect urinalysis of FSGS?

Answer 11

Podocytes seem to be getting injured and dying, which leads to scarring.
Urinalysis of FSGS will show podocytes in urine, and proteinuria do to decreased podocyte function.

Question 12

Lots of things can injure podocytes, but there might be underlying genetic susceptibility in patients who develop FSGS.

Answer 12

Yeah.. like age, toxins, immune complexes, metabolic factors, HTN…

Question 13

What does PAS staining of Membranous Glomerulopathy look like?

Answer 13

Thickened GBM with sclerosis and basement membrane spikes.

Question 14

What does trichrome staining of Membranous Glomerulopathy look like?

Answer 14

Subepithelial proteinaceous deposits.

Question 15

What does Membranous Glomerulopathy look like in immunofluorescence?

Answer 15

Granular staining for various things… including complement.
Surprisingly, there isn’t other evidence of inflammation.
I should emphasize that Membranous Glomerulopathy has immune complexes without inflammation.

Question 16

How will secondary Membranous Glomerulopathy look different from primary Membranous Glomerulopathy on EM?

Answer 16

Primary: only subepithelial electron-dense deposits.
Secondary: deposits in other places, such as mesangium, subendothelial.

Question 17

Etiologies of Membranous Glomerulopathy?

Answer 17

Primary = idiopathic/unknown.
Secondary... can be due to a lot of things:
	-infection (HBV, HCV, malaria, etc.)
	-neoplasms
	-drugs (gold salts, penicillamine)
	-rheumatologic diseases (SLE, etc.)

Question 18

What does the location of the (non-inflammatory…) immune-complexes in Membranous Glomerulopathy suggest about the way the complexes are formed?

Answer 18

Suggests that the complexes are formed in situ after the constituent elements cross the GBM…

Question 19

Natural history of Membranous Glomerulopathy?

Answer 19

20% have spontaneous remission.
60% have persistent proteinuria.
20% have progressive disease.