Amyloidosis

Question 1

What is amyloidosis

Answer 1

Extracellular deposits of misfolded proteins

Question 2

What is AL amyloidosis

Answer 2

Production of abnormal Ig light chains from plasma cells
Light chains enter the blood, form long fibrils & cause amyloid deposits

Question 3

Amyloidosis can cause end organ damage, describe some examples

Answer 3

Heart - cardiomyopathy
Bowel - malabsorption
Skin - cutaneous amyloidosis
Nerves - autonomic or peripheral neuropathy
Kidneys - nephrotic syndrome
Liver - organomegaly & deranged LFTs

Question 4

How would you monitor AL amyloidosis

Answer 4

Ig light chain levels in blood

Question 5

What is the screening vs diagnostic vs organ monitoring tests for amyloidosis

Answer 5

Screening
- protein electrophoresis of blood & serum free light chain
- blood inflammatory markers

Diagnostic
- organ biopsy (often renal): congo red staining gives green apple bifringence under polarised light

Organ monitoring
- Echocardiogram/cardiac MRI
- U&Es & nephrotic range proteinuria
- Radio-labelled serum amyloid P (SAP) scan: shows extent of disease

Question 6

How would you treat AL amyloidosis

Answer 6

• Similar to myeloma with chemo
• Aim is to switch off abnormal light chain supply