Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
22 Cards in this Set
- Front
- Back
|
What is amyloidosis?
|
A heterogenous group of diseases due to protein misfolding and characterized by deposition of amyloid in tissues
|
|
|
What is amyloid?
|
It is an abnormal insoluble material composed of protein fibrils derived from normal, soluble proteins
|
|
|
How do you identify amyloid hystologically?
|
By staining biopsy tissue with congo red dye (which will turn specimen green)
|
|
|
What are the 3 most common forms of amyloid?
|
AL, AA, and Ab
|
|
|
What is AL amyloid?
|
Amyloid light chain, derived from plasma cells and contains Ig light chains. Often assoicated with myeloma and causes death by heart disease in 40% of patients
|
|
|
What is AA amyloid?
|
Amyloid-associated, a unique non-Ig protein synthesized by the liver
|
|
|
What is Ab amyloid?
|
It is found in the cerebral lesion of Alzheimer disease
|
|
|
What is the difference between primary and secondary systemic amyloidosis?
|
Primary is from abnormal Ig production, secondary is caused by infection, inflammatory diseases, and sometimes cancer
|
|
|
What is the major cause of symptoms in secondary amyloidosis?
|
Nephrotic syndrome leading to renal failure and death
|
|
|
Which tissues are best to biopsy when looking for amyloidosis?
|
Rectal and gingival tissues will have amyloid in up to 75% of cases with generalized amyloidosis
|
|
|
What are Bence Jones proteins?
|
Light chains produced by plasma cells (AL amyloid) that are excreted in urine or found in plasma of pts with multiple myeloma
|
|
|
What is the most common form of amyloidosis?
|
Primary (AL) myeloma-associated amyloidosis. Most have benign monoclonal gammopathy
|
|
|
What is the most common cause of secondary (reactive systemic AA) amyloidosis?
|
Chronic inflammation caused by autoimmune diseases like RA, ankylosing spondylitis, and inflammatory bowel disease
|
|
|
What is transthyretin?
|
It is thyroxine and retinol binding protein. Wild type is responsible for senile systemic amyloidosis
|
|
|
What is hemodialysis-associated amyloidosis?
|
b-2 microglobulin amyloid protein not removed by dialysis. Forms deposits in bones and joints
|
|
|
What are the forms of hereditary/familial amyloidosis?
|
Familial Meditarranean fever cuased by autosomal recessive gene (AA proteins) and Familial amyloid polyneuropathies caused by autosomal dominant gene (mutant transthyretins)
|
|
|
What type of amyloid typically causes localized, organ specific amyloidosis?
|
AL, usually affects lung, larynx, skin, urinary bladder, tongue, and peri-ocular. Common to find amyloid nodules
|
|
|
How is amyloid associated with Alzheimer's disease?
|
There are plaques of Ab proteins derived from amyloid precursor proteins (APP's). Mutations in APP's are common in Alzheimer's
|
|
|
What is APP?
|
Amyloid precursor protein, cleaved by beta and gamma secretases from cell membrane. An insoluble Ab peptide is formed leading to plaques.
|
|
|
What is Presenilin-1 protein?
|
It is associated with gamma-secretase function (which is what cleaves APP's to form insoluble Ab proteins)
|
|
|
What are neurofibrillary tangles?
|
They are intracellular collections of tau, a microtubule associated protein. Found in high amounts in Alzheimer's pts
|
|
|
HSV-1 and Ab plaques
|
Viral DNA found associated with >80% of Ab plaques and changes in APP distribution.
|
