Amyloidosis

Question 1

What is amyloid?

Answer 1

Misfolded protein that deposits in the extracellular space and damaging tissue; Deposition can be systemic or localized

Question 2

What are the common features of amyloid?

Answer 2

Beta-pleated sheet configuration, Congo red staining, apple-green birefringence

Question 3

What is primary amyloidosis? What condition is it associated with?

Answer 3

Systemic deposition of AL amyloid which is derived from Ig light chain. Plasma cell dyscrasias.

Question 4

What is Familial Mediteranean Fever and how does it contribute to amyloidosis?

Answer 4

FMF causes an increase in serum SAA (also increases in chronic inflamm and malignancy) with concurrent fever and serosal inflammation. SAA deposits as AA amyloid in tissues

Question 5

Clinical findings of systemic amyloidosis

Answer 5

Nephrotic syndrome (organ most commonly involved), Restrictive cardiomyopathy/arrythmia, Tongue enlargement, malabsorption because of thickened bowel and hepatosplenomegaly

Question 6

How do you get a Dx for amyloidosis?

Answer 6

Biopsy. Abdominal fat pad or rectum are good targets

Question 7

Tx for amyloidosis

Answer 7

Organ transplant

Question 8

What is senile cardiac amyloidosis? What are the Syx? Population?

Answer 8

Non-mutated serum transthyretin deposited in the heart; Usually asymptomatic; 25% of individuals >80 yo

Question 9

What is familial amyloid cardiomyopathy? Population?

Answer 9

Mutated serum transthyretin deposits in heart leading to restrictive cardiomyopathy; 5% of African Americans carry the mutated gene

Question 10

What is non-insulin-dependent diabetes mellitus (type II)?

Answer 10

Amylin (derived from insulin) deposits in the islets of the pancreas

Question 11

What is the amyloid associated with Alzheimer disease?

Answer 11

ABeta amyloid (derived from Beta-amyloid prrecursor protein) deposits in the brain forming amyloid plaques

Question 12

What is the association between Down syndrome and Alzheimer disease?

Answer 12

Gene for Beta-Amyloid Precursor Protein present on chromosome 21. People with Down syndrome have trisomy 21 and develop Alzheimer disease by age of 40

Question 13

What is dialysis-associated amyloidosis?

Answer 13

Beta2-microglobulin deposits in joints because it is not filtered well in dialysis

Question 14

How are medullary carcinoma of the thyroid and amyloidosis related?

Answer 14

Tumor cells produce calcitonin which deposits within tumor and causes amyloidosis