Amyloidosis

Question 1

What is amyloidosis?

Answer 1

extracellular deposition of insoluble fibrillar protein termed “amyloid”

Question 2

What does the accumulation of amyloid cause?

Answer 2

tissue/organ dysfunction

Question 3

Name the ways in which amyloidosis can be classified

Answer 3

LOCATION
- systemic or localized

PRECURSOR PROTEIN
(e.g. AL in myeloma - A for Amyloid, L for Light chain)

Question 4

Ix to diagnose amyloidosis

Answer 4

• Congo red staining: apple-green birefringence
• serum amyloid precursor (SAP) scan
• biopsy of skin, rectal mucosa, or abdominal fat

Question 5

Positive amyloidosis finding on congo red staining

Answer 5

apple-green birefringence

Question 6

Name the subtype:

Most common form
L = Light chain fragment
(Myeloma, Waldenstrom’s, MGUS)

Features:
- nephrotic syndrome
- cardiac/neuro involvement
- macroglossia
- periorbital eccymoses

Answer 6

AL Amyloidosis

Question 7

Name the subtype:
Precursor serum amyloid A protein (acute phase)

• Seen in chronic infection/inflammation
  e.g. TB, bronchiectasis, RA

Features:
- renal involvement most common

Answer 7

AA Amyloidosis

Question 8

Name the subtype

Precursor protein is beta-2 microglobulin, part of the major histocompatibility complex

Usually associated with patients on renal dialysis

Answer 8

Beta-2 microglobulin amyloidosis