Fogo, Ch. 4 - Minimal change disease & FSGS

Question 1

What patients are most often affected by MCD and FSGS?

Answer 1

MCD: Children

FSGS: African americans and hispanics

Question 2

What are the LM findings in MCD?

Answer 2

Nothing; glomeruli appear normal.

Question 3

What are the LM findings in FSGS NOS? How can this be distinguished from normal age-related glomerulosclerosis?

Answer 3

Segmental sclerosis (even 1 glom coutns). Global glomerulosclerosis is normla with age, up to (age/2 - 10)%.

Question 4

Recall the morphology of FSGS variants.

Answer 4

Collapsing: Collapse of capillary loops with overlying podocyte proliferation

Tip: Glomerular sclerosis at the tubular pole with adhesion to the urinary outlet

Cellular: Foam cells, segmental proliferative podocytosis

Hilar: Hyalinosis in most of the sclerotic glomeruli.

Question 5

What does the presence of AIN indicate in FSGS?

Answer 5

Favors a drug etiology.

Question 6

What are the IF findings in MCD/FSGS?

Answer 6

Usually nothing. FSGS can have nonspecific IgM/C3.

Question 7

What are the EM findings in MCD?

Answer 7

Podocyte foot effacement

Question 8

What are the EM findings in FSGS?

Answer 8

Some podocyte foot effacement, vacuolization and microvillous transformation. Reticular aggregates in collapsing-variant.

Question 9

What is the etiology of MCD?

Answer 9

Unknown, probably has to do with abnormal cytokines, increased CD80. Associated with drugs, toxins, and Hodgkin disease.

Question 10

What is the etiology of FSGS?

Answer 10

Extremely multifactorial, probably all have circulating abnormal factors and dysregulated podocytes. Also many familial forms.

Question 11

What genes are implicated in familial forms of FSGS?

Answer 11

Those that are involved in the podocyte slit diaphragm: Nephrin, alpha-actinin…

Question 12

What is the outlook for MCD?

Answer 12

Great; good prognosis and response to steroids.

Question 13

What is the outlook for FSGS? Its variants?

Answer 13

Generally poor/progressive.

Cellular is abruptly bad.

Tip lesion has good prognosis.

Question 14

What drugs, viruses, and genetic linkages are associated with FSGS?

Answer 14

Pamidronate

Parvovirus

ApoA1 (L1?)

Question 15

Summarize the clinical significance and management of C1q nephropathy.

Answer 15

Young patients present with nephrotic syndrome. Poor prognosis, no known etiology or pathogenesis.

Question 16

Summarize the LM, IF, and EM findings of C1q nephropathy.

Answer 16

LM: Can have segmental sclerosis or be totally normal.

IF: Prominent mesangial C1q.

EM: Mesangial deposits, foot process effacement.

Question 17

What conditions are associated with hilar-type secondary FSGS?

Answer 17

DM, HIV, obesity, IVDU, interferon treatment.

Question 18

What morphologic features are seen with obesity in FSGS?

Answer 18

Marked glomerulomegaly with GBM thickening and mild mesangial expansion.

Question 19

What morphologic features are seen with reflux in FSGS?

Answer 19

Periglomerular fibrosis and interstitial scarring.

Question 20

What morphologic features are seen with HIV in FSGS?

Answer 20

Cystic dilatation and injury out of proportion to scarring.