Amyloidosis is a rare and serious protein deposition disease. It is caused by an abnormal protein called amyloid that builds up in tissues or organs. As the number of amyloid protein deposits increase in a tissue or organ, they interfere with the tissue or organ’s healthy function. Eventually, amyloid protein deposits cause symptoms and organ failure. Amyloidosis is sometimes fatal.
Amyloid protein deposits, or amyloidosis, may be localized to organs, such as the lung, skin, bladder, or bowel, or they can be systemic. “Systemic” means that the deposits may be found throughout the body. Systemic amyloidosis is the most common. Although amyloidosis is not a type of cancer, it may be associated with certain blood cancers like multiple myeloma.
It is a very rare disorder. Because it is such a rare disorder, it has been difficult to study. However, doctors and researchers have begun to understand more about amyloidosis over the past few decades. Research continues to uncover more about this disorder.
Amyloidosis on skin
- The cause for amyloid to be produced and to collect in the tissues is not known. The risk of getting amyloidosis is not connected to what a person eats (including how much protein) or does for a living or to the amount of stress in one’s life
- The disease starts in the bone marrow. Bone marrow creates red and white blood cells, platelets and antibodies that protect the body against infection. After the antibodies have done their work, the body breaks them down.
- When the bone marrow cells produce antibodies that cannot be broken down, amyloidosis develops. The antibodies build up in the blood and eventually get deposited in the tissues as amyloid.
Types of Amyloidosis
There are different types includes the following:
Light chain (AL) amyloidosis
This is the most common type of amyloidosis in the United States. The amyloid proteins that build up in the tissues in this condition are known as light chains. They can either be a kappa or lambda light chains. It is a disorder of the plasma cells. Plasma cells are a type of white blood cell responsible for the production of immunoglobulins or antibodies, which are a type of protein that fights infection. In AL amyloidosis, the light chain proteins are misshapen and produced in excess. The deposit in tissues and can damage 1 or more organs. The heart, kidneys, nerves, and gastrointestinal system are the most common organs affected. Because AL amyloidosis is associated with the overproduction of plasma cell proteins, it is linked to multiple myeloma.
Autoimmune (AA) amyloidosis
AA amyloidosis is also called “secondary amyloidosis” or “inflammatory amyloidosis.” In this condition, the amyloid protein that builds up in the tissues is called the A protein. AA amyloidosis is associated with some chronic diseases, such as diabetes, tuberculosis, rheumatoid arthritis, and inflammatory bowel disease. It may also be linked to aging. AA amyloidosis can affect the spleen, liver, kidneys, adrenal glands, and lymph nodes. Lymph nodes are tiny, bean-shaped organs that fight infection.
Hereditary or familial amyloidosis
Hereditary amyloidosis is rare. It can be passed from generation to generation within a family. The proteins produced in hereditary amyloidosis may cause problems with the heart and may cause carpal tunnel syndrome and eye abnormalities. The most common subtypes involve a protein called transthyretin (TTR).
This section covers AL, AA, and hereditary amyloidosis. Other types of amyloidosis include beta-2 microglobulin amyloidosis, which occurs in some patients with chronic kidney problems, and types of amyloidosis located in specific areas of the body.
Factors that increase your risk include:
Age: Most people diagnosed with AL amyloidosis, the most common type, are between ages 60 and 70, although earlier onset occurs.
Sex: Nearly 70 percent of people with AL amyloidosis are men.
Other diseases: Having a chronic infectious or inflammatory disease increases your risk of AA amyloidosis.
Family history: Some types of amyloidosis are hereditary.
Kidney dialysis: Dialysis can’t always remove large proteins from the blood. If you’re on dialysis, abnormal proteins can build up in your blood and eventually be deposited in tissue. This condition is less common with modern dialysis techniques.
Race: People of African descent appear to be at higher risk of carrying a genetic mutation associated with the type of amyloidosis that can harm the heart.
The symptoms vary widely, depending on which tissues and organs are affected. In some cases, it has no symptoms until extensive tissue damage has occurred.
Some of the symptoms may include:
- Ankle and leg swelling (oedema)
- Muscular weakness
- Unexplained weight loss
- Pins and needles or numbness in the extremities
- Memory loss
- Swollen tongue
- Dizziness when standing up suddenly (orthostatic hypotension).
The potential complications depend on which organs the amyloid deposits affect. It can seriously damage your:
Kidneys: Amyloid can harm the kidneys’ filtering system, causing the protein to leak from your blood into your urine. The kidneys’ ability to remove waste products from your body is lowered, which may eventually lead to kidney failure.
Heart: Amyloid reduces your heart’s ability to fill with blood between heartbeats. Less blood is pumped with each beat, and you may experience shortness of breath. If amyloidosis affects your heart’s electrical system, your heart rhythm may be disturbed.
Nervous system: You may experience pain, numbness or tingling of the fingers or numbness, lack of feeling or a burning sensation in your toes or the soles of your feet. If amyloid affects the nerves that control your bowel function, you may experience periods of alternating constipation and diarrhea.
If the condition affects nerves that control blood pressure, you may experience dizziness or near fainting when standing too quickly.
Your doctor will ask about your symptoms and medical history. It’s important to tell your doctor as much as you can, because amyloidosis symptoms can be similar to those of other conditions. Misdiagnosis is common.
Your doctor may use the following tests to help make a diagnosis:
Blood and urine tests: These tests can be done to assess amyloid protein levels. Blood tests can also check your thyroid and liver function.
Echocardiogram: This imaging test uses sound waves to create pictures of your heart.
Biopsy: For this test, a doctor removes a sample of tissue from your liver, nerves, kidneys, heart, abdominal fat, or other organs. Analyzing the piece of tissue can help your doctor figure out what type of amyloid deposit you have.
Bone marrow aspiration and biopsy: Bone marrow aspiration uses a needle to remove a small amount of fluid from inside your bones. A bone marrow biopsy removes some of the tissue from inside your bone. These tests may be done together or separately. The samples are sent to a lab, where they’re checked for abnormal cells.
If a diagnosis is made, your doctor will figure out which type you have. This can be done with tests like immunochemical staining and protein electrophoresis.
The treatment makes a big difference in life expectancy and quality of life for people with amyloidosis.
Based on the type you may need one or more of these treatments:
Chemotherapy: This is the backbone of the treatment strategy to control the disease in most patients with AL amyloidosis. Read more about chemotherapy.
Peripheral blood stem cell transplant: Our physicians use this procedure to treat some patients with AL amyloidosis. The new blood stem cells enable you to receive higher doses of chemotherapy.
Organ transplant: Patients with various types of amyloidosis may benefit from an organ transplant, such as heart, liver or kidney transplants. Stanford is one of the leading centers in the world for heart transplantation in people who have amyloidosis.
Clinical trials: Stanford researchers are testing new potential treatments for multiple types of amyloidosis in our clinical trials. Our physicians can determine if you are eligible to participate in one of our trials.
Because amyloidosis is such a rare disease, it is important to find an amyloid treatment center with an experienced team and specially trained physicians. At the Stanford Amyloid Center, our team is dedicated to expert care and treatment for our patients with all types of amyloidosis.
In primary amyloidosis, the disorder is sporadic and no preventive interventions are recognized.
In secondary amyloidosis, development in a chronic inflammatory state is directly related to uncontrolled inflammation and hepatic production of serum amyloid A protein. Treatment of the underlying condition to suppress the inflammation reduces the subsequent risk of secondary amyloidosis.
Patients with multiple myeloma and monoclonal gammopathy should have a regular clinical assessments. Repeat serum protein electrophoresis testing is indicated annually. Routine screening for amyloidosis is not indicated unless the patient has increasing fatigue or edema, or if urinalysis shows proteinuria.