Amyloidosis (Phyllis' Version)

Question 1

What is amyloidosis

Answer 1

Multisystem disorder caused by abnormal folding of proteins that are deposited as amyloid fibrils in tissues, disrupting their normal function.

• Beta-pleated sheet structure
• Resistant to enzyme degradation

Question 2

Different types of amyloid and which is most common

Answer 2

Primary (AL amyloidosis) - most common

Secondary (AA amyloidosis)

Haemodialysis associated

Familial amyloidosis

Question 3

Stain for amyloid and what happens

Answer 3

Apple green birefringence with Congo red stain under polarized light

Question 4

Tell me about AL amyloid

Answer 4

PRIMARY (AL amyloidosis)
* Most common
* Deposition of Ig light chains
* Most associated with multiple myeloma (although most don’t have multiple myeloma)
* Most have monoclonal Ig, free light chains in serum and urine (Bence Jones) and
increased bone marrow plasma cells

Question 5

Tell me about secondary amyloidosis

Answer 5

SECONDARY (AA amyloidosis)
* Amyloid formed from serum amyloid A = acute phase protein, therefore build up occurs
secondary to chronic infections / inflammation
o E.g.autoimmunediseases(60%):RA,ankylosingspondylitis,IBD o E.g.chronicinfections:TBosteomyelitis,IVDU(skininfections)
o Non-immune:renalcellcarcinoma,Hodgkin’s

Question 6

Tell me about haemodialysis associated amyloid

Answer 6

Deposition of beta2-microglobulin
* Usually occurs in someone with longstanding chronic renal failure esp. if they are on
peritoneal dialysis
* Associated with carpal tunnel syndrome

Question 7

Tell me about familial amyloidosis

Answer 7

Most common = Familial Mediterranean Fever (AR)
* AA amyloid, predominant renal deposition

Clinical features: caused by amyloid deposits in various organs:
* KIDNEY: nephrotic syndrome = most common presentation
* HEART: restrictive cardiomyopathy, conduction defects, heart failure, cardiomegaly
* LIVER/SPLEEN: hepatosplenomegaly
* TONGUE: macroglossia in 10%
* NEUROPATHIES: including carpal tunnel