Amyloidosis is a rare disorder resulting from the buildup of a waxy substance known as amyloid in various organs and tissues. The substance is comprised of certain types of protein that, when present in excess amounts in the bloodstream, may seep out into the tissues and solidify.
The most common sites for amyloid deposition are the kidneys, liver, spleen, heart, skin, gastrointestinal tract, and nervous system. Interference with function of the involved organs, symptoms, and prognosis depend upon the location and the amount of accumulated amyloid protein. In most cases, however, outlook is poor. Kidney failure, congestive heart failure, cardiac arrhythmias, and gastrointestinal bleeding are the major life-threatening complications of amyloidosis.
What Causes Amyloidosis?
- In most cases, amyloidosis is caused by an abnormal protein (beta-amyloid), which is similar to the antibodies normally found in the blood; this condition is known as primary (idiopathic) amyloidosis.
- Familial (hereditary) amyloidosis results from genetic changes that cause the body to produce abnormal proteins.
- Secondary amyloidosis, which is much more rare, may occur as a complication of certain long-standing inflammatory or infectious diseases, including rheumatoid arthritis, ankylosing, spondylitis, osteomyelitis, leprosy and tuberculosis. Again, the culprit is an abnormal protein in the blood that is deposited in the tissues.
- Some forms of amyloidosis, affecting primarily the nerves, are inherited.
- Long-term hemodialysis therapy may lead to amyloidosis.
- Alzheimer’s disease is thought to be related to a certain form of amyloidosis.
- Amyloidosis of the heart may develop as a result of old age.
Symptoms of Amyloidosis
- Weight loss and fatigue are common
- If the heart is affected: congestive heart failure with excessive accumulation of fluid in the tissues (edema); breathing difficulty; fatigue; heart rhythm disturbances with palpitations
- If the kidneys are affected: symptoms of kidney failure
- If the skin is affected: slightly raised, waxy nodules clustered in the armpits, groin, face, neck, or ears; purple discoloration of the skin, bleeding into the skin (purpura) around the eyes and easy bruising
- Swelling of the tongue often occurs and may interfere with swallowing
- Sleep apnea
- If the gastrointestinal tract is affected: diarrhea; abdominal pain; blood in stool; perforated bowel, GI bleeding or blockage and slow movement of matter through the GI tract
- Enlarged liver
- Impaired function of the spleen, adrenal gland and other endocrine glands
- Lung problems
- If the nervous system is affected: dizziness upon standing; numbness or tingling in the hands or feet; inability to sweat; hoarseness
- If the joints are affected: arthritic pain; morning stiffness, swelling in the shoulders
- Memory loss
- There are no known ways to prevent most forms of amyloidosis.
- Effective treatment of conditions such as tuberculosis or rheumatoid arthritis can prevent chronic inflammation that causes secondary amyloidosis.
- People with hereditary amyloidosis should receive genetic counseling to learn about the risks of passing the illness to their children.
- Patient history and physical examination are needed.
- Protein levels in the blood and urine are measured.
- Needle biopsy (removal of a tissue sample for microscopic examination) of abdominal fat is usually performed. Sometimes it is necessary to biopsy the kidney, rectum, or other parts of the body.
- In hereditary amyloidosis, DNA tests are performed to detect the genetic cause for the condition.
- Special x-rays of tissue may show the structure of amyloid deposits.
How to Treat Amyloidosis
- For primary amyloidosis, chemotherapeutic drugs are often given.
- The underlying disorder is treated in secondary amyloidosis.
- Colchicine may be of benefit in treating both primary and secondary amyloidosis.
- Medications may be given to treat the organs affected by amyloidosis.
- Dialysis or kidney transplantation may be needed for patients with renal failure.
When to Call a Doctor
Amyloidosis can manifest itself in a myriad of ways. See a doctor if you develop unexplained weight loss, severe fatigue, or other symptoms of amyloidosis.
Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference
Simeon Margolis, M.D., Ph.D., Medical Editor
Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50
Updated by Remedy Health Media