Amyloidosis

Amyloidosis is a rare condition in which abnormal proteins precipitate inside the tissues causing organ damage. These proteins are caused by either specific types of blood cancer, inflammatory process, or are hereditary.

Clumps of abnormally shaped proteins, called amyloid deposits or fibrils, either spread around the body or gather on your tissues and organs. Different types of amyloidosis affect different organs like the heart, liver, kidneys, and lungs.

Systemic amyloidosis, which is widespread, is the most common type, affecting multiple tissues or organs, and can sometimes cause organ damage which is life-threatening. Localized amyloidosis affects only one organ or part of the body. The main types of amyloidosis, categorized by the type of amyloidosis protein affected, include:

• Amyloid light chain (AL): A plasma cell disorder in which plasma cells make too many abnormal cells. These ‘light chains’ misfold, clump and form amyloid fibrils. These end up on organs, typically the heart (cardiac amyloidosis), kidneys, stomach, liver, large intestine, skin and nerves.
• Amyloid serum A protein (AA or SAA): Occurs when there is too much serum A protein, which builds up when there is abnormal inflammation in the body for a prolonged period. AA may be caused by inflammatory bowel disease, rheumatoid arthritis and chronic infections and can affect the kidneys, liver, intestines and stomach.
• Amyloid transthyretin protein (ATTR): A protein made by the liver, transthyretin carries vitamin A and thyroid hormone in the blood. In ATTR, an inherited disorder, the transthyretin protein breaks apart, which creates fibrils that go to the heart or your nerves.

What causes amyloidosis?

Amyloidosis happens when our proteins change, forming clumps of misshapen proteins, which then precipitate inside certain tissues or organs. There are many different types of amyloid proteins.

Amyloidosis can happen if you have an underlying health condition which is linked to amyloidosis, such as the blood disorder multiple myeloma[KP1].

Other things that may cause the main types of amyloidosis include:

• Amyloid serum A protein (AA): Amyloidosis may develop if you have had an inflammatory illness.
• Amyloid transthyretin protein/TRR protein (ATTR): If you inherit mutated DNA which makes your TTR proteins less stable and more likely form amyloid fibrils, you are more at risk of this type of amyloidosis.

What are the symptoms of amyloidosis?

The symptoms of amyloidosis vary depending on the proteins involved and where their fibrils form. General symptoms of amyloidosis include:

• Fatigue or extreme tiredness, a symptom of anemia due to low levels of normal red blood cells.
• Joint pain, caused by high levels of amyloid serum A protein.
• Rashes, which can be caused by amyloidosis and lead to rashes or bruising.
• Unexplained weight loss.
• Weak grip, a symptom of carpal tunnel syndrome.

Who is affected by amyloidosis?

Amyloidosis is usually diagnosed in people aged 50 to 65. It is more common in men than women.

How is amyloidosis diagnosed?

Your doctor will perform several tests if they suspect amyloidosis. A bone marrow aspiration and biopsy will be used to identify the type of mutated protein causing amyloidosis. Diagnostic tests include:

• Blood tests: To check the levels of abnormal proteins in the blood.
• Urine tests: To check for abnormal protein levels.
• Computed tomography (CT) scan: To see damage to affected organs.
• Echocardiogram: To assess the condition of the heart.

How is amyloidosis treated?

Treatment for amyloidosis addresses the symptoms, damage to organs and underlying cause.

• Combination of targeted therapy, immune therapy, and chemotherapy.
• Bone marrow or stem cell transplantation: Stem cells can help make healthy new cells, so a transplant replaces damaged stem cells with healthy ones from our own body or a donor.
• Organ transplantation: In certain types of amyloidosis, a liver, kidney or heart transplantation may be needed.

Amyloidosis can’t be prevented, but it may be possible to control how much it affects your quality of life by understanding your risk. Your doctor can then monitor you and aim to diagnose and treat the condition while it is in the early stages.

Our Multiple Myeloma and Amyloidosis Program offers advanced treatment options and specialized care and support for people diagnosed with multiple myeloma, amyloidosis and other plasma cell disorders.

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