What is autoimmune amyloidosis disease of the heart?

Amyloidosis is a condition in which certain proteins in the body do not fold properly making them accumulate in various organs. Most amyloidosis involving the heart is due to transthyretin amyloidosis or light chain amyloidosis.

Transthyretin is a protein made in the liver that carries thyroid hormone and vitamin A throughout the body. Light chains are normally part of the structure of antibodies.

When light chains or transthyretin proteins are present in excessive amounts or do not function normally, they can accumulate in heart tissue, impairing the heart’s ability to pump and causing the condition called cardiac amyloidosis.

Amyloidosis, including cardiac amyloidosis, is not considered an autoimmune disease. However, autoimmune diseases, such as rheumatoid arthritis, may cause chronic inflammation that leads to light chain amyloidosis. Effective treatment of the autoimmune disease can prevent light chain amyloidosis.