amyloidosis

Question 1

definition of amyloidosis

Answer 1

Any histological tissue specimen that binds the cotton wool dye, Congo red, and demonstrates green birefringence when viewed under polarised light is, by definition, an amyloid deposit. The patient with this deposit has amyloidosis. Deposits of amyloid may be localised in tissue or part of a systemic process. Progressive deposition of amyloid is disruptive to tissue and organ function and manifests its clinical sequelae by the dysfunction of those organs in which it deposits

Question 2

types of amyloidosis

Answer 2

1. primary
   (Patients with AL produce immunoglobulin light chains that are inherently prone to misfolding from a native alpha-helical state into an insoluble beta-pleated sheet configuration.)
2. secondary
   (related to long-standing infections such as bronchiectasis (cystic fibrosis), osteomyelitis, chronic mycobacterial infections, inflammatory bowel disease, familial periodic fever syndromes (e.g., familial Mediterranean fever, tumour necrosis factor receptor-associated periodic fever syndromes, muckle-Wells syndrome, hyper-IgD syndrome), and Castleman’s disease.)
3. inherited amyloidosis (familial)
4. senile (deposition exclusively in the heart, in elderly)

Question 3

investigations

Answer 3

1st line:

• serum immunofixation + urine immunofixation => presence of monoclonal antibodies
• immunoglobulin free light chain assay => abnormal kappa to lambda ratio
• bone marrow biopsy => clonal plasma cells

Question 4

symptoms

Answer 4

weight loss
fatigue
SOB on exertion (amyloid cardiomyopathy)

Question 5

signs

Answer 5

• raised JVP

- lower extremity oedema

Question 6

risk factors

Answer 6

• MGUS (monoclonal gammopathy of undetermined significance)
• inflammatory polyarthropathy
• chronic infections
• IBD
• familial periodic fever syndromes
• castleman’s disease