Amyloidosis is a term for a group of devastating, complicated and rare disorders. Amyloidosis is caused by the abnormal folding, aggregation and accumulation of abnormal protein fibrils in organs and tissues of the body. These abnormal protein deposits (amyloid) disrupt normal body function and, without treatment, will eventually lead to death. There are more than 20 different types of amyloidosis. It is not a cancer but is equally serious and in most cases is incurable at this time.
The main types of Amyloidosis are:
- AL Amyloidosis (immunoglobulin light chain amyloidosis) – This systemic disease is usually caused by a bone marrow disorder.
- AA Amyloidosis – This type of amyloidosis is caused by deposition of the serum amyloid A protein (SAA) when SAA is elevated over many years due to long-term inflammatory disease or infection.
- Hereditary/Familial Amyloidosis – There are a number of types of hereditary amyloidosis, caused by an inherited gene mutation, which leads to a lifelong production of the abnormal protein amyloid. The most common types of hereditary amyloidosis are ATTRmut (transthyretin gene mutation) and AFib (fibrinogen alpha chain gene mutation).
- Wild Type Transthyretin Amyloidosis, ATTRwt, previously known as senile cardiac amyloidosis. This type of amyloidosis occurs when transthyretin amyloid deposits in the heart. As opposed to ATTRmut, this type of amyloidosis is NOT an inherited disease.
- Localized Amyloidosis – In this type of amyloidosis the amyloid protein is both produced and deposited in a single organ.
For further information on the types of amyloidosis refer to the National Amyloidosis Centre London.
Diagnosis
The diagnosis of amyloidosis is difficult. Because the symptoms of amyloidosis mimic other diseases it is often not diagnosed early. The presence of amyloidosis can only be confirmed at this time by a tissue biopsy. Further tests are then carried out to establish which of the many different types of amyloidosis a person has and to what degree any organs and tissues are involved.
The PA Hospital Amyloidosis Centre offers high-level amyloid diagnostic and typing services not available elsewhere in Australia. Sometimes this typing is difficult and the results may take some weeks before they are known. However it is essential that your type of amyloidosis is correctly typed, as treatment is different for the different types of amyloidosis.