AL amyloidosis Flashcards
1
Q
what is it?
A
- Rare disorder
- Small plasma cell clone like in MGUS
- Mutation in the light chain > altered structure
- Precipitates in tissues as an insoluble beta pleated sheet
2
Q
pathophysiology
A
- Accumulation in tissues causes organ damage
- Slowly progressive
- Multisystem disease
- Different protein to SAA amyloidosis (chronic inflammation) and familial amyloidosis
3
Q
how does it present?
A
- Kidney – nephrotic syndrome
- Heart – cardiomyopathy
- Liver – organomegaly, deranged LFTs
- Neuropathy – autonomic, peripheral
- GI tract – malabsorption
4
Q
how is it investigated and staged?
A
Organ biopsy confirming AL amyloid deposition
o Congo red stain
o Rectal or fat biopsy maybe be done if high clinical suspicion (less invasive)
Evidence of deposition in other organs
o ‘SAP scan’
- Indium123-labelled serum amyloid P (SAP) scintigraphy used to monitor disease burden and response
- I123-labelled SAP localises rapidly and specifically to amyloid deposits in proportion to the quantity of amyloid present
o Echocardiogram/cardiac MRI
o Nephrotic range proteinuria
5
Q
how is it treated?
A
similar treatment to myeloma - chemo to switch off light chain supply
poor prognosis especially if cardiac amyloid
