What is amyloidosis?
The term amyloid means “starch-like” and amyloidosis represents a group diseases in which abnormal proteins, called amyloids, accumulate in the body and cause problems with bodily functions. Doctors back in the 19th century believed that an abnormal material similar to starchy plant cellulose was the culprit – hence its name. Amyloidosis occurs with some types of cancer, but amyloid itself is not a form of cancer. Nevertheless, amyloidosis can be a serious, life-threatening condition.
Nearly every tissue in the human body can be affected. Amyloidosis is classified as either localized or systemic. Localized amyloidosis occurs when amyloid builds up in only one place or organ, such as the brain or heart, and impair their function. Systemic amyloidosis occurs when amyloids build up throughout the entire body.
There are two major classifications of localized amyloidosis:
Ab (amyloid beta) protein amyloidosis is the accumulation of beta amyloid protein and is associated with Alzheimer’s disease.
AIAPP amyloidosis is the accumulation of islet amyloid polypeptide (IAPP) in the pancreas of people with type 2 diabetes.
Systemic amyloidosis is further classified or described by the cause: primary, secondary or hereditary amyloidosis. The cause of primary amyloidosis is not known, but it is thought to be related to the immune system. Secondary amyloidosis is caused by other diseases, disorders and conditions, including certain cancers, chronic (long-term) inflammatory disorders, and chronic infections. Hereditary amyloidosis is a genetic condition that is passed down through families, from parent to child, and is the most rare form of the disease.
Amyloidosis is also classified by the type of abnormal protein being produced. This classification system uses letters to represent the abnormal protein. Systemic amyloidosis is generally classified as AL, AA or ATTR:
AL (amyloid light chain) amyloids are typically associated with primary systemic amyloidosis. AL amyloids tend to accumulate in skin, nerves, heart, digestive system, kidneys, liver, spleen, and blood vessels. AL or primary amyloidosis is the most common form of the disease in the United States. However, it is still a relatively rare disease.
AA (amyloid A) amyloids are usually associated with chronic diseases (secondary systemic amyloidosis) and tend to accumulate in the spleen, liver, kidneys, adrenal glands, and lymph nodes.
ATTR (transthyretin) amyloids are produced in the hereditary form of amyloidosis and accumulate in nearly every tissue and organ in the body.
A variety of other forms of amyloidosis can also occur, such as dialysis-related amyloidosis caused by long-term dialysis.
The symptoms of amyloidosis vary widely and depend on the specific type of amyloidosis and the organs it affects. General symptoms of amyloidosis include fatigue, joint pain, unexplained weight loss, skin changes, and weakness. Because the symptoms of amyloidosis are common to a wide variety of other diseases, disorders and conditions, a correct diagnosis is very important. Contact your health care provider for a physical exam for symptoms that are persistent or recurrent. Early diagnosis offers the best chance for a hopeful outlook.
The treatment of amyloidosis will depend on the specific type of amyloidosis and the affected organs. You can help minimize your symptoms and your risk of complications by following the treatment plan you and your health care professional design specifically for you.
Amyloidosis is a serious and potentially life-threatening condition. Complications, multiple organ failure, and death are possible. Seek immediate medical care (call 911) if you have amyloidosis and develop any serious symptoms, such as difficulty breathing, shortness of breath, persistent swelling of the ankles or other body parts, no urine output, palpitations, or uncontrolled bleeding.
What are the symptoms of amyloidosis?
Specific symptoms of amyloidosis will depend on which organs are affected by the disease. This can make diagnosis particularly challenging in secondary amyloidosis because the underlying disease, disorder or condition may have similar symptoms.
General symptoms of amyloidosis include:
Anemia (low red blood cell count)
Numbness or tingling in the arms or legs
Serious symptoms that might indicate a life-threatening condition
Amyloidosis can lead to serious and potentially life-threatening complications. Seek immediate medical care (call 911) if you, or someone you are with, have amyloidosis and any of the following symptoms:
Decreased or no urine output
Difficulty breathing or shortness of breath
Irregular heartbeat or palpitations
Persistent swelling of the ankles or other body parts
Unusual or sudden weakness or numbness
What causes amyloidosis?
The specific types of amyloidosis and the underlying cause are listed below.
AL (amyloid light chain) or primary amyloidosis
The cause of primary amyloidosis is not known, but it is related to the abnormal production of antibodies by cells called plasma cells. Plasma cells are found mainly in your bone marrow. Antibodies are made of proteins and help your body fight infections and diseases. Normally, your body can break down antibodies and recycle them. In amyloidosis, plasma cells produce antibodies that your body cannot break down. Instead, they accumulate in tissues and organs and cause complications.
AA (amyloid A) or secondary amyloidosis
Secondary amyloidosis is caused by other diseases, disorders and conditions. These are usually chronic infections, chronic inflammatory disorders, and certain cancers including:
Ankylosing spondylitis (inflammatory disease of the spine and pelvis)
Bronchiectasis (destruction of the large airways)
Familial Mediterranean fever (FMF)
Hairy cell leukemia
Juvenile idiopathic arthritis
Osteomyelitis (bone infection)
Renal cell carcinoma
Rheumatoid arthritis (chronic autoimmune disease characterized by joint inflammation)
Sjogren’s syndrome (autoimmune disease characterized by the destruction of moisture-producing glands)
Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)
Tuberculosis (serious infection affecting the lungs and other organs)
ATTR (transthyretin) or hereditary amyloidosis
Hereditary amyloidosis is a condition caused by a defective gene that is passed down from parent to child. The most common form of hereditary amyloidosis is caused by a defect in the TTR gene. In this form of amyloidosis, your liver produces most of the abnormal protein that accumulates throughout the body.
Localized amyloidosis is caused by the accumulation of abnormal amyloid proteins in a specific area or organ of the body. The two most common types of protein that accumulate are A beta (Aβ) amyloid and islet amyloid polypeptide (IAPP). Localized amyloidosis is usually associated with another condition, such as diabetes, chronic dialysis, or Alzheimer’s disease.
A number of factors may increase your chances of developing amyloidosis, although not all people with risk factors will develop the condition. Common risk factors include:
Age older than 40 years
Family history of hereditary amyloidosis
Other diseases, such as chronic infections, chronic inflammatory disorders, and certain cancers
Reducing your risk of amyloidosis
The primary and hereditary forms of amyloidosis have no known prevention. However, you may be able to prevent or delay secondary amyloidosis by seeking treatment and following your treatment plan for diseases known to cause it.
How is amyloidosis treated?
Amyloidosis is a chronic condition. Treatment depends on the type of amyloidosis, your overall health, your treatment preferences, and the presence of any underlying diseases, disorders or conditions. All treatments have risks and benefits. Your health care provider is best able to guide your treatment decisions based on your specific circumstances.
Treatment of AL (amyloid light chain) or primary amyloidosis
Specific treatment of primary amyloidosis may include:
Chemotherapy to eliminate the plasma cells that are producing abnormal antibodies. While amyloidosis is not cancer, chemotherapy may effectively control plasma cells.
Corticosteroids such as prednisone to suppress plasma cell activity
Stem cell or bone marrow transplantation to replace bone marrow cells destroyed by high-dose chemotherapy
Treatment of AA (amyloid A) or secondary amyloidosis
Treatment of secondary amyloidosis focuses on aggressively treating the underlying disease, disorder or condition. There is no specific treatment for the amyloidosis itself, but bone marrow or stem cell transplantation may help certain people.
Treatment of ATTR (transthyretin) or hereditary amyloidosis
Because the liver is the site of abnormal protein production in this form of amyloidosis, liver transplantation is sometimes used to treat this disorder. Liver transplantation has been very effective when used in people who are proper candidates for this procedure.
Other treatments for amyloidosis
Other methods for controlling amyloidosis include:
Dietary therapy to decrease the production of amyloids and ease the work of affected tissues and organs. However, there is no link between amyloidosis and a protein-rich diet. Your health care provider can help you with a specific diet plan that meets your needs.
Organ transplantation, such as kidney or heart transplantation, in properly selected patients
Symptomatic treatment, which generally uses medications and other supportive treatments to relieve the symptoms caused by amyloidosis. This type of treatment is not aimed at treating the amyloidosis itself.
Complications of amyloidosis can be serious and even life threatening. Left untreated, amyloidosis can be fatal. Early diagnosis and treatment of amyloidosis offers the best chance for a hopeful prognosis and for effectively managing the disease. You can best treat amyloidosis and lower your risk of complications, or delay the development of complications, by following the treatment plan you and your health care professional design specifically for you.
Over time, amyloidosis can lead to serious complications including: