Medically Reviewed by Dr. K on 13 May 2022.
Amyloidosis is a disease in which an abnormal protein, known as an amyloid, accumulates in the body within tissues and organs. This accumulation affects the normal function of such organs, leading to serious health issues that can cause potentially fatal organ failure.
Causes and Types of Amyloidosis
There are many variations of proteins that can lead to a build up of amyloid, however only a select few are linked to serious health issues. The pattern of accumulation and which organs these proteins deposit into will determine the type of amyloidosis that a patient will be diagnosed with. Amyloid proteins are able to deposit anywhere throughout the body, but it can also only focus on accumulating in one area.
Types of amyloidosis:
-AL amyloidosis (immunoglobulin light-chain amyloidosis).
AL amyloidosis (immunoglobulin light-chain amyloidosis) is the most common subtype of amyloidosis, also known as primary amyloidosis. AL, amyloid light-chains, is the specific type of protein that causes the disease. AL amyloidosis develops when bone marrow produces defective antibodies that are unable to break down. There is no known cause of this disease, however it is associated with multiple myeloma, a blood cancer. This disease can affect the heart, liver, kidneys, intestines and nervous system.
AA amyloidosis, previously referred to as secondary amyloidosis, is a disease resulting from inflammatory chronic diseases like rheumatoid arthritis, Crohn’s inflammartory bowel disease or ulcerative colitis. AA derives from the type of protein, amyloid type A protein, that goes on to cause the disease. It predominantly affects the kidneys, but can also affect the heart, liver and intestinal tracts.
– Dialysis-related amyloidosis (DRA).
Dialysis-related amyloidosis (DRA) generally affects older adults or patients receiving dialysis for over 5 years. DRA is caused by beta-2 microglobulin deposits that accumulate in the blood. This disease generally affects bones, joints and tendons.
– Familial or hereditary amyloidosis.
Family (hereditary) amyloidosis is a rarer subtype of amyloidosis that is passed down genetically from parents to children. It can be cause by a defective protein like transthyretin (TTR). It generally affects the heart, kidneys, liver and nervous system. A patient with many genetic abnormalities has a higher predisposition of developing amyloid disease.
– Age-related (senile) systemic amyloidosis
Age-related (senile) systemic amyloidosis develops from accumulation of normal transthyretin (TTR) within the heart and other organs. This subtype of amyloidosis is more prevalent in older men.
– Organ-specific amyloidosis.
Organ-specific amyloidosis is a subtype of amyloidosis that causes amyloid proteins to accumulate only in single solitary organs. If it accumulates within the skin, it is known as cutaneous amyloidosis. Some amyloid deposits are associated with Alzheimer’s disease.
Referenced on 2.3.2021:
- National Amyloidosis Centre: “Amyloidosis Overview."
- MedLine Plus: “Amyloidosis."
- National Kidney and Urologic Diseases Clearinghouse: “Amyloidosis and Kidney Disease."
- American Society of Clinical Oncology: “Amyloidosis."
- Amyloidosis Foundation: “Amyloidosis Information: A General Overview for Patients."
- Mayo Clinic: “Amyloidosis.”