Amyloidosis

Question 1

What are the various stains that can be used for amyloid proteins? What colours do they give?

Answer 1

H&E - pink, hyaline
Methyl violet/crystal violet - metachromasia (rose -pink)
Congo red - Pink-red (under light microscopy); red-green birefringence (under polarising light)
Thioflavin-T/Thioflavin-S - fluorescent under UV light
Immunohistochemistry - amyloid protein reacts with antibody

Question 2

What is the difference between AA and AL proteins?

Answer 2

Both are amyloid proteins, however-

• AL is made of light chain Igs in plasma cells
• AL is non-Ig derived but is synthesised in liver, in responses to secretion of IL-1, IL-6

Question 3

What is transthryetin?

Answer 3

• normal serum protein (transports retinol and thyroxine)
• mutated foms typical of familial congenital disease
• normal form found in hearts of aged patients (senile cardiac amyloidosis)

Question 4

What disease cause secondary amylodosis?

Answer 4

(Previously)

• bronchiecstasis
• TB
• osteomyelitis

(Nowadays)

• rheumatoid arthritis
• ankylosing spondylosis
• inflammatory bowel diseases
• chronic skin infections (drug abuse)
• solid tumours

Question 5

What are the features of famililal mediterranean fever?

Answer 5

• autosomal recessive
• systemic amyloidosis (widespread)
• xs IL-1 synthesis
• fever attacks + serous inflammation
• AA proteins

Question 6

What are the features of familial idiopathic neuropathy?

Answer 6

• autosomal dominant
• amyloid deposits in peripheral and autonomic nerves
• made of mutant transthyretin

Question 7

What are the features of familial idiopathic neuropathy?

Answer 7

• autosomal dominant
• amyloid deposits in peripheral and autonomic nerves
• made of mutant transthyretin