What is amyloidosis?

Amyloidosis (am-uh-loi-DO-sis) is the buildup of a protein called amyloid in your body's tissues or organs. Amyloid isn't normally found in the body, but it can be formed from several different types of protein.

Amyloid proteins may affect only a single organ or, often, are spread throughout the body (systemic). They can affect different organs in different people, and there are different types of amyloid proteins. Depending on the type of amyloidosis, amyloid can deposit in the heart, kidneys, nervous system, spleen, digestive tract, or other organs and tissues.

There's no cure for amyloidosis, which, when severe, can be life-threatening, but treatments can help you manage symptoms and slow production of amyloid protein. To recommend the right treatment, your doctor needs to do tests to identify which type of amyloid protein is in your body, where it's been deposited, and how it's affecting your tissues or organs.

As you learn more about what amyloidosis is, how it may affect your life and what your treatment options are, it may help to understand more about the different types of amyloidosis.

Types of amyloidosis

Many types of amyloidosis exist. Several major types are:

AL amyloidosis

This type of amyloidosis, also called immunoglobulin light chain amyloidosis, is the most common type in the United States. It can affect your heart, kidneys, skin, nerves and liver.

With AL amyloidosis, your bone marrow produces abnormal plasma cells — a type of white blood cell that makes proteins called antibodies to fight infections. The abnormal cells called light chains can't be broken down. They then deposit in your tissues as amyloid and keep your tissues from working normally.

Sometimes AL amyloidosis is related to multiple myeloma, a type of cancer that forms in plasma cells.

AA amyloidosis

AA amyloidosis mostly affects the kidneys. Sometimes it can affect the digestive tract, liver or heart.

AA amyloidosis is associated with ongoing infectious or inflammatory diseases, such as tuberculosis, rheumatoid arthritis or inflammatory bowel disease.

In AA amyloidosis, the protein that builds up in your tissues is known as an A protein.

Dialysis-related amyloidosis

This type of amyloidosis usually affects people with chronic kidney disease, who've been on dialysis for a long time. It results when amyloid proteins from beta-2-microglobulin are deposited from the blood into joints and tendons.

Dialysis-related amyloidosis can cause joint pain, stiffness and fluid buildup. Shoulder pain and wrist pain and tingling (carpal tunnel syndrome) are common.

Hereditary amyloidosis (familial amyloidosis)

Though rare, some types of amyloidosis can be genetically passed on by parents to their children. Many different types of inherited gene abnormalities are associated with an increased risk of amyloid disease.

The type and location of the gene abnormality can affect the risk of certain complications, the age at which symptoms first appear and the way the disease progresses over time.

The most common type of hereditary amyloidosis is related to a mutation of the transthyretin gene (TTR). Sometimes called ATTR, this type causes amyloid protein to build up in and affect the heart and the body's nerves that are outside the brain and spinal cord (peripheral nerves).

Why type is important

These are some of the major types of amyloidosis, but other types also exist. A tissue biopsy — either of the organ affected, if only one is affected, or of fat tissue if more than one area is affected — is the only way to definitively diagnose amyloidosis. Certain tests, such as mass spectrometry, can identify the type.

The type of amyloidosis is important because treatment varies greatly and depends on your specific condition. You can also have more than one type of amyloidosis. Talk with your doctor about biopsy and what other tests you may need.

May 01, 2019 See more In-depth