Amyloidosis is a rare disease that involves the buildup of a specific protein called amyloid.
Unlike other proteins, amyloid does not have a supportive role in the body. Instead, the buildup of amyloid protein leads to organ damage.
Amyloidosis commonly affects organs, including the heart, kidneys, and liver.
In this article, learn more about the causes and symptoms of amyloidosis, as well as about how doctors treat it.
Amyloidosis occurs when the body produces amyloid proteins. The reason amyloids develop may vary, depending on the type of amyloidosis present.
Amyloidosis can affect just one organ or may be widespread. Widespread amyloidosis affects several organs and body systems.
Types of amyloidosis include:
- immunoglobulin light-chain amyloidosis (AL)
- secondary amyloidosis (AA)
- familial amyloidosis (ATTR)
- beta-2 microglobulin amyloidosis (Abeta2m)
- localized amyloidosis (ALoc)
- other familial amyloidoses
According to the Amyloidosis Foundation, AL occurs more often than other types of the disease. The “AL” stands for “amyloid” and “light chain.”
AL amyloidosis involves the development of abnormal antibody proteins in the plasma cells of the bone marrow.
AA amyloidosis is when a buildup of amyloid proteins happens as a reaction to another illness.
An inherited gene mutation can also cause a hereditary form of amyloidosis.
Although anyone can develop amyloidosis, certain factors increase a person’s risk of the disease. These include:
- Age: Amyloidosis can develop in young adults, but the most common form of amyloidosis occurs more often between 50 and 80 years of age.
- Family history: There is a genetic form of amyloidosis, so having a close blood relative, such as a parent, with the condition may increase a person’s risk.
- Sex: Approximately two-thirds of people with AL amyloidosis are male.
- Dialysis: People who undergo long term dialysis to treat kidney disease are at an increased risk of developing a specific form of amyloidosis.
- History of inflammatory disease: Some conditions, such as arthritis or inflammatory bowel disease, can trigger AA amyloidosis. According to the National Organization for Rare Diseases, about 50% of people with AA amyloidosis have rheumatoid arthritis.
The buildup of amyloid proteins interferes with the normal functions of the organs. Symptoms can vary, however, depending on which organs amyloidosis affects.
Common symptoms may include:
- unexplained weight loss
- edema, or swelling
- chest pain
- abnormal heart rhythm
- bruising around the eyes
Occasionally, amyloid deposits may buildup on a specific organ without widespread development in other areas. For example, amyloids may deposit on the skin, bladder, or larynx.
It is more common, however, for amyloidosis to affect more than one organ.
The symptoms of amyloidosis can mimic other diseases. For example, symptoms that affect kidney function may lead to a misdiagnosis of other renal conditions.
Since amyloidosis is a rare disease, it may take some time for doctors to make a diagnosis. Correctly diagnosing amyloidosis is essential to target the most effective treatment.
Diagnostic testing for amyloidosis may include:
- Tissue biopsy: A tissue biopsy involves removing a small sample of tissue to check for amyloid deposits. A doctor typically takes a sample from a fat pad under the skin in the abdomen or from an organ.
- Bone marrow biopsy: Removal of bone marrow involves checking for the presence of amyloid deposits. Doctors will usually take the bone marrow from the pelvic bone.
- Blood and urine tests: Various urine and blood tests can help determine which organs are involved. For example, urine tests may indicate kidney damage, whereas blood tests may measure problems with the heart.
There is currently no cure for amyloidosis, but the condition is treatable.
Treatment involves slowing the progression of the disease, decreasing symptoms, and improving a person’s quality of life.
Treatment depends on the severity of symptoms and the type of amyloidosis.
Possible therapies to decrease amyloid protein development include:
Chemotherapy is the use of various drugs to kill the abnormal blood cells that help form amyloids.
A doctor may recommend the following chemotherapy drugs:
The type of chemotherapy a person receives will depend on the extent of their symptoms, their age, and which organs symptoms affect.
Stem cell transplant
In some instances, a doctor may recommend stem cell transplantation after chemotherapy.
After destroying the abnormal cells that produce amyloids with chemotherapy, stem cell transplants can help develop healthy bone marrow.
Receiving a stem cell transplantation is a complex process, and not every person with amyloidosis qualifies.
Controlling underlying diseases
Treatment for people with AA amyloidosis often includes controlling the underling inflammatory disease that led to the buildup of amyloids.
Once a person treats the underlying condition, such as rheumatoid arthritis, they may experience fewer symptoms of amyloidosis.
A person may also need to treat complications of the disease or make changes in their diet or lifestyle to make managing the disease easier.
Supportive treatment can include a wide variety of medications and therapies, including:
Because amyloid proteins can damage the organs, complications are frequent.
Possible complications of amyloidosis include:
- Kidney damage: Amyloidosis often affects the kidneys. If the kidneys are unable to remove waste products effectively, it can lead to kidney damage or failure.
- Heart failure: Amyloid buildup may adversely affect heart function. It can lead to an abnormal heart rhythm and the inability of the heart to pump efficiently.
- Nervous system complications: The nervous system may not function as it should, which can lead to dizziness, numbness, digestive issues, and pain in the joints.
Although ongoing research continues, there is currently no cure for amyloidosis. The outcome of the disease often depends on the organs involved.
Treatment for amyloidosis may slow the development of abnormal proteins and the progression of the disease. Many treatment options also help people manage their symptoms.
Amyloidosis usually affects more than one organ, which makes it advantageous to work with a team of specialists to develop an individualized treatment plan.
As amyloidosis is uncommon, people may find it helpful to speak to others with the condition at a local or online support group. The Amyloidosis Foundation provides a list of these groups here.