Amyloidosis is a rare and potentially fatal disease that occurs when amyloid proteins build up in the body's tissues and organs. The abnormal protein is produced by cells in the bone marrow.
Amyloidosis affects different organs in different individuals. However, it usually occurs in the heart, kidneys, liver, spleen, nervous system and gastrointestinal tract.
There are several different types of amyloidosis. The disease is classified based on where the protein is produced. The most common type of the disease, primary systemic amyloidosis, is a bone marrow disorder. Other types, which originate in the liver, are considered to be familial or inherited. Amyloidosis may also be the result of kidney disease in people who have undergone long-term dialysis.
The exact cause of amyloidosis is unknown, and currently there is no cure for the disease. However, medications and special diets may help relieve symptoms and reduce the production of the amyloid protein.
Although amyloid is an abnormal protein, the amount of protein consumed plays no role in the development of the disease. Also, there appears to be no link between amyloidosis and stress or occupation.
Primary amyloidosis: Primary amyloidosis is the most common form of the disease. This form primarily affects the heart, kidneys, tongue, nerves and intestines. For the most part, it is not associated with other diseases. However, in rare occasions, it may be linked to myeloma (type of bone marrow cancer).
The cause of primary amyloidosis is unknown. However, researchers have discovered that it begins in the bone marrow. In addition to producing blood cells and platelets, the bone marrow also makes antibodies, which help fight against disease and infection. After the antibodies destroy the infection or disease, the body breaks them down and recycles them. Amyloidosis occurs when the antibodies cannot be broken down, which subsequently leads to build of the antibodies in the blood stream. Eventually the antibodies leave the bloodstream and can deposit in tissues as amyloid and cause damage.
Secondary amyloidosis: This form occurs in association with chronic infectious or inflammatory diseases, such as tuberculosis, rheumatoid arthritis or osteomyelitis (bone infection). It primarily affects your kidneys, spleen, liver and lymph nodes, though other organs may be involved. Treatment of the underlying disease may help stop this form of amyloidosis.
Hereditary amyloidosis: This form of amyloidosis is inherited. This type often affects the nerves, heart and kidneys.
Hemodialysis-associated amyloidosis: Hemodialysis-associated amyloidosis occurs in individuals who have undergone long-term (more than five years) kidney dialysis. Symptoms of this form include bone lesions and chronic arthritis.
Most people are diagnosed with amyloidosis after the age of 40.
Men are much more likely (60-65%) than women to develop the disorder, according to the American Society of Hematology. The reason for this is unknown.
Individuals who have a chronic infectious or inflammatory disease may be more likely to develop the disorder. For instance, 10-15% of people who have multiple myeloma (type of bone marrow cancer) develop amyloidosis.
Since some forms of amyloidosis are inherited, individuals who have a family history of the disorder are often at an increased risk.
Individuals who have kidney diseases that require kidney dialysis (especially if treatment lasts longer than five years) may be at increased risk for dialysis-associated amyloidosis. This is because dialysis cannot remove large proteins from the blood. Therefore, abnormal proteins may build up and deposit in surrounding tissues. However, this condition is rare with modern dialysis techniques.
Symptoms vary depending on the organs that are affected. Some individuals may be asymptomatic. If left untreated, amyloidosis can result in death.
Common symptoms include: swollen legs/ankles, weakness, weight loss, shortness of breath, numbness, tingling in hands and feet, diarrhea, abnormal hair loss, severe fatigue, macroglossia (enlarged tongue), skin changes, chronic arthritis, nerve damage, heart damage, kidney damage, respiratory failure, bone lesions, arrhythmia (irregular heartbeat) and difficulty swallowing.
Kidney damage: When amyloidosis affects the kidneys, the body's filtering system is damaged. Consequently, protein may leak from the blood into the urine. If a significant amount of protein is lost from the blood, fluid may leak out of the blood vessels. This, as well as salt-retention, may cause inflammation of the feet, ankles and calves (edema). If the kidney's filtering system becomes severely damaged and is unable to adequately remove waste from the body, the condition may progress to kidney failure.
Heart damage: The most common symptom when amyloidosis affects the heart is shortness of breath. When the protein builds up in the heart, the heart is unable to adequately fill with blood in between heartbeats. As a result, less blood is pumped throughout the body with each beat, and the muscles and organs receive less oxygen. Individuals may also experience arrhythmia.
Nervous system damage: Another complication of amyloidosis is disruption of the nervous system. About 50% of amyloidosis patients experience carpal tunnel syndrome, which causes pain, numbness and tingling of the fingers. Other patients may experience numbness in the feet or a burning sensation due to nerve irritation.
If the disorder affects the nerves that control bowel function, individuals may also experience periods of constipation or diarrhea.
In some cases, the disorder may affect the nerves that control blood pressure, which may result in dizziness, light-headedness or a drop in blood pressure.
Other complications may include endocrine failure, respiratory failure or death.
During a physical examination, the healthcare provider may detect an enlarged liver or spleen. The physician may conduct several tests, to confirm the diagnosis.
Blood and urine tests could possibly detect amyloidosis. However a tissue biopsy is the only definitive test for the diagnosis of this disorder. During a biopsy, the patient is given a local anesthetic, and the physician removes a small sample of tissue with a needle. If it is suspected that the individual has systemic amyloidosis (occurring in several areas throughout the body), the biopsy may be taken from the abdominal fat, bone marrow or rectum, depending on where symptoms arise. The sample is then examined under a microscope for signs of the protein.
In some cases, tissue samples may be taken from other areas of the body, like the liver or kidney. These procedures may require hospitalization.
An echocardiogram may show signs of cardiomyopathy if amyloidosis is affecting the heart.
While there is currently no cure for amyloidosis, some medical therapies may help relieve symptoms and reduce production of the amyloid protein. The disease is typically treated with medications and diet.
Since amyloidosis can potentially cause several complications, individuals may need to follow a special diet. For instance, if amyloidosis affects the heart or kidneys, it may be recommended that the patient follow a low-salt diet to control fluid retention.
For individuals who have secondary amyloidosis, the primary goal is to treat the underlying condition. For instance, some individuals may take anti-inflammatories to treat rheumatoid arthritis.
Peripheral blood stem cell transplantation: During peripheral blood stem cell transplantation, high-dose chemotherapy is administered along with transfusion of stem cells (immature blood cells) to replace damaged bone marrow. These stem cells may come from the patient (autologous transplant) or from a donor (allogeneic transplant). Autologous transplant is the preferred method.
Anti-cancer medication ("antineoplastics"): Melphalan (Alkeran©), an agent used to treat certain types of cancer, has been prescribed to amyloidosis patients as well. Other types of chemotherapy treatments, like melphalan with high-dose dexamethasone or VAD (vincristine, adriamycin and dexamethasone), are being tested for safety and efficacy in the treatment of amyloidosis. Other medications, including thalidomide, a drug used to treat multiple myeloma, are also being tested for their ability to inhibit the disease.
Corticosteroids: Corticosteroids like prednisone have been prescribed to amyloidosis patients because of their anti-inflammatory effects.
Liver transplantation: For hereditary amyloidosis, one possible therapy may be liver transplantation because the protein that causes this form of amyloidosis is produced in the liver.
Unclear or conflicting scientific evidence :
DMSO (dimethyl sulfoxide) : DMSO may change the course of amyloidosis if treatment is started early. However, there is not much scientific support for this claim.
Use caution with urinary tract cancer or liver or kidney dysfunction. Avoid if allergic to DMSO or if pregnant or breastfeeding.
Traditional or theoretical uses lacking sufficient evidence :
Germanium : Animal study suggests that germanium compounds may prevent amyloidosis. Results can only be considered preliminary at this time. Additional research is needed to make a conclusion.
Avoid if allergic or hypersensitive to germanium, its compounds or germanium-containing plants. Avoid if pregnant or breastfeeding.
Resveratrol : Preliminary data suggests that resveratrol may play a role in the prevention of amyloidosis. High quality clinical research is needed to better understand this relationship.
Avoid if allergic or hypersensitive to resveratrol, grapes, red wine, or polyphenols. Resveratrol is generally considered safe and is commonly found in food and beverages. Use cautiously with bleeding disorders or abnormal blood pressure. Use cautiously with drugs that are broken down by the body's cytochrome P450 system. Avoid if pregnant or breastfeeding.
Currently, there is no known method to prevent amyloidosis.
This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
- American Society of Hematology. www.hematology.org. Accessed May 11, 2009.
- Amyloidosis Support Network. www.amyloidosis.org. Accessed May 11, 2009.
- Kuga, N., Oboshi, S., Sato, H., and Sato, R. Inhibition of senile amyloidosis of mice by biscarboxyethyl germanium sesqui-oxide. Acta Pathol.Jpn. 1976;26(1):63-71. View abstract
- National Kidney and Urological Diseases Information Clearinghouse. Amyloidosis and Kidney Disease. http://kidney.niddk.nih.gov. Accessed May 11, 2009.
- Natural Standard: The Authority on Integrative Medicine. www.naturalstandard.com. Copyright © 2009. Accessed May 11, 2009.
- The Cleveland Clinic Health Information Center. Amyloidosis. www.clevelandclinic.org. Accessed May 11, 2009.
Copyright © 2011 Natural Standard (www.naturalstandard.com)