Fogo, Ch. 19 - Other organized deposits

Question 1

How do fibrillary GNitis and immunotactoid glomerulopathy present?

Answer 1

Proteinuria/hematuria, renal insufficiency, hypertension.

Question 2

What is a key association of immunotactoid glomerulopathy?

Answer 2

Half of patients have a lymphoproliferative disease.

Question 3

What are the LM findings in fibrillary GNitis?

Answer 3

Mesangial hypercellularity, thickened capillary walls. May or may not have crescents.

Question 4

What are the IF findings in fibrillary GNitis?

Answer 4

Coarse linear (or confluent granular) IgG, C3, and light chain.

Question 5

What are the (defining) EM features of fibrillary GNitis?

Answer 5

18-20nm fibrils in the mesangium and basement membrane. Unlike amyloid, congo red negative.

Question 6

What are some clinical associations of fibrillary GNitis?

What is the outlook?

Answer 6

Carcinomas, dysproteinemia, and autoimmune disease.

Poor outlook; chronic course with most suffering renal failure.

Question 7

What are fibrillary deposits composed of?

Answer 7

Unknown; seems to contain some mixture of immunoglobulins, light chains, and fibronectin.

Question 8

What are the LM findings in immunotactoid glomerulopathy?

Answer 8

Membranoproliferative glomerulonephritis. Sometimes membranous pattern.

Question 9

What are the IF findings in immunotactoid glomerulopathy?

Answer 9

Non-specific IgG, C3, and light chain.

Question 10

What are the (defining) EM features in immunotactoid glomerulopathy?

Answer 10

Numerous coarse hollow-cored fibrils measuring 20-80nm. Resembles microtubules.