When abnormal amyloid proteins build up in body tissues, this is known as amyloidosis. Amyloidosis has a wide range of causes that include both genetic conditions and those caused by aging. Because the proteins can build up in various organs all over the body, people can suffer from a wide range of symptoms and the cause cannot be confirmed without biopsy. This condition is fatal without treatment, and there is no known cure.
There are nearly 200 different types of amyloidosis, but the three most common are known as light chain amyloidosis, autoimmune amyloidosis, and hereditary amyloidosis. Each type has different causes, different symptoms, and different treatments:
1. Primary Light Chain Amyloidosis
This is the most common type of amyloidosis in the United States, and while it can be a side effect of other diseases, it frequently occurs on its own. In this form of amyloidosis, bone marrow cells produce abnormally folded proteins called light chains instead of antibodies. These light chains build up in organs in the body and cause lasting damage. The kidneys are most frequently affected, but light chain proteins also commonly build up in the heart, lungs, skin and liver. This form of amyloidosis originates in the bone marrow, so treatment is frequently chemotherapy and a bone marrow transplant.
2. Amyloidosis caused by autoimmune conditions
Occasionally when someone suffers from another autoimmune condition, it can trigger autoimmune amyloidosis. The most common conditions that trigger this are tuberculosis, and inflammatory autoimmune conditions such as inflammatory bowel disease and rheumatoid arthritis. When the amyloidosis is caused by an autoimmune condition it mostly affects the kidneys. In these cases, the original illness is usually treated and the amyloidosis symptoms get better as the original illness does. Treatment for specific symptoms can help people manage the condition.
3. Amyloidosis caused by gene mutation
There are several types of amyloidosis under the umbrella of hereditary amyloidosis. These are caused by a genetic mutation and patients are born with the disease. This form of amyloidosis tends to run in families, and patients may not show symptoms until they are older. Children with an affected parent have a 50% chance of being born with a genetic mutation, but not all people with the mutation become symptomatic. People may frequently be misdiagnosed with genetic amyloidosis. In this type of amyloidosis, the dysfunctional protein is produced in the liver, so patients may eventually need a liver transplant to treat it.