Amyloidosis Flashcards
What is amyloidosis?
extracellular deposition of insoluble fibrillar protein termed “amyloid”
What does the accumulation of amyloid cause?
tissue/organ dysfunction
Name the ways in which amyloidosis can be classified
LOCATION
- systemic or localized
PRECURSOR PROTEIN
(e.g. AL in myeloma - A for Amyloid, L for Light chain)
Ix to diagnose amyloidosis
- Congo red staining: apple-green birefringence
- serum amyloid precursor (SAP) scan
- biopsy of skin, rectal mucosa, or abdominal fat
Positive amyloidosis finding on congo red staining
apple-green birefringence
Name the subtype:
Most common form
L = Light chain fragment
(Myeloma, Waldenstrom’s, MGUS)
Features:
- nephrotic syndrome
- cardiac/neuro involvement
- macroglossia
- periorbital eccymoses
AL Amyloidosis
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
AA Amyloidosis
Name the subtype
Precursor protein is beta-2 microglobulin, part of the major histocompatibility complex
Usually associated with patients on renal dialysis
Beta-2 microglobulin amyloidosis