1.5 Amyloid Flashcards
What, generally, is amyloid? Where in tissues does it deposit?
A misfolded protein that deposits in the extracellular space, and damages tissues
What is the usual secondary structure of amyloid?
Beta-pleated sheet configuratio
What is the stain that is used to highlight amyloid? What technique is used to help visualize the stain?
Congo red
Polarized light causes it to show apple green birefringence
What is the type of amyloid that is depositied with primary amyloidosis?
AL amyloid, derived from Ig light chain
What are plasma cell dyscrasias?
Abnormalities of the plasma cells that produces systemic amyloid deposition
What is the amyloid that is deposited with secondary amyloidosis? What protein is this derived from?
AA amyloid
SAA protein, which is an acute phase reactant increased in chronic inflammatory states
What is the function of SAA? What, then, is secondary amyloidosis associated with?
Acute phase reactant that is increased in chronic inflammatory states
Associated with autoimmune diseases, malignancy
What is familial mediterranean fever? How does it present?
- AR Dysfunction of PMNs that causes them to be activated in the absence of infection
- Presents with episodes of fever and acute serosal infection
What is the relation between familial Mediterranean fever and amyloidosis?
Causes an increase in amyloid deposition
What is the most commonly involved organ with amyloidosis? What does this usually cause?
Kidney
-Nephrotic syndrome
What type of heart problems occur with amyloidosis?
Restrictive cardiomyopathy
What are the GI consequences of amyloid deposition?
- tongue enlargement
- Malabsorption
- HSM
How do you diagnose amyloidosis?
Tissue bx
Where are biopsies usually taken to diagnose amyloidosis?
Fat pad and rectum
What is the treatment for damage organs 2/2 amyloidosis?
Must be transplanted–amyloid cannot be removed
What is the type of amyloid that is deposited in senile cardiac amyloidosis?
Non-mutated serum transthyretin
What is the usual presentation of senile cardiac amyloidosis?
Asymptomatic
How common is senile cardiac amyloidosis?
Common–25% of people over 80 yo
What is the disease that has non-mutated amyloid deposition in the heart?
Senile cardiac amyloidosis
What is familial amyloid cardiomyopathy? What is the protein that is deposited here?
Mutated serum transthyretin is deposited, leading to a restrictive cardiomyopathy
What type of heart cardiomyopathy is had with deposition of mutated transthyretin?
Restrictive (familial amyloid cardiomyopathy)
Which ethnicity is affected with familial amyloid cardiomyopathy?
African americans
What type of amyloid is deposited in the beta cells of the pancreas with DM II? What is this derived from?
Amylin–derived from insulin
What type of amyloid is deposited with AD? What does this form in the brain?
Abeta–amyloid plaques
What is the A-beta amyloid that is deposited in AD derived from? What chromosome is this found on?
Beta-amyloid precursor protein on chromosome 21
What type of amyloid is deposited with dialysis-associated amyloidosis? Where is this usually deposited?
Beta-2 microglobulin
Joints and carpal tunnel
What is beta 2 microglobulin derived from?
MHC class I receptor
Why is it that patients on dialysis get amyloidosis?
Beta-2 microglobulin is not filtered well by dialysis
What is the function of the C cells of the thyroid?
Produce calcitonin
What type of amyloid is found with medullary carcinoma of the thyroid?
Calcitonin
