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Definition - A disorder of unknown cause, in which insoluble
protein-fibers become deposited in tissues and organs, impairing
their function.
Causes, incidence, and risk factors - The cause of primary
amyloid is unknown. Symptoms vary widely because they are
related to the organs that become affected with the deposits.
They occur in the following organs: tongue, intestines, skeletal
and smooth muscles, nerves, skin, ligaments, heart, liver,
spleen, and kidneys. Cardiomyopathy, renal failure, carpal
tunnel syndrome, malabsorption (inadequate absorption of nutrients
from the intestinal tract), gastrointestinal reflux, and other
conditions can result. The deposits infiltrate the organs,
causing them to lose resilience and become stiff, resulting
in barriers to absorption and diffusion of metabolites. Secondary
amyloidosis can occur from an infection or existing inflammatory
disease.
The incidence of primary amyloid is estimated at 8 out of
1,000,000 people. Risk factors have not been identified.
Prevention: - There is no known prevention.
Symptoms:
- fatigue
- numbness of hand and feet
- weak hand grip
- weight loss
- shortness of breath
- swelling of the extremities
- swallowing difficulties
- irregular heart rhythm
- bleeding into the skin
- enlarged tongue
Additional symptoms that may be associated with this disease:
- wheezing
- weakness
- urine output, decreased
- other tongue problems
- stools, clay colored
- rashes
- muscle contractions
- joint pain
- hoarseness or changing voice
Signs and tests - A physical examination may show
enlarged liver or spleen. There may be signs of heart failure.
If specific organ damage is suspected, testing to confirm
amyloidosis of that organ may be performed.
- A biopsy of a tissue or organ is positive for amyloid.
- A skin biopsy that includes subcutaneous fat, a rectal
mucosa biopsy, or a bone marrow biopsy are safe, and likely
to help confirm the diagnosis.
- A cardiac evaluation may reveal arrhythmias, abnormal
heart sounds, or signs of heart failure.
- ECG shows abnormalities
- An echocardiogram shows poor wall motion because of a
stiff heart muscle (cardiomyopathy).
- A renal evaluation may reveal renal failure or nephrotic
syndrome.
- Urinalysis shows protein, casts, or fat bodies.
- Serum creatinine is increased.
- BUN is increased.
- An abdominal ultrasound may reveal enlarged liver or spleen.
- An evaluation for carpal tunnel syndrome may reveal involvement
of the nerve:
- Nerve conduction velocity shows a conduction block.
- Hand grips are weak because of weakness of the thumb.
- This disease may also alter the results of the following
tests:
- tongue biopsy
- rectal biopsy
- nerve biopsy
- myocardial biopsy
- gum biopsy
- carpal tunnel biopsy
- abdominal wall fat pad biopsy
- ACE levels
- Bence-Jones protein (quantitative)
- immunoelectrophoresis - serum
- quantitative immunoglobulins (nephelometry)
- protein, urine
Treatment - There is no specific treatment for amyloidosis.
Please refer to the Treatment Options page for more information:
Organ involvement such as heart failure, kidney failure, and
other problems are treated as appropriate.
Expectations (prognosis) - The severity of the disease
depends upon
- How soon after the onset of symptoms you start treatment
- The aggressiveness of the disease (it seems to vary for
each individual)
- Which body organs are involved and to what degree
- The age and general health of the patient
It is important to understand that it is the heart, kidney
and/or other organ involvement may lead to organ failure and
death.
Complications - heart failure, kidney failure, endocrine
failure (hormonal disorder), respiratory failure among others
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