source: Myeloma UK summary/abstract:
The term ‘amyloidosis’ is a general term used for a group of diseases where an abnormal protein, called amyloid, accumulates in the tissues. The build-up of amyloid protein is called an ‘amyloid deposit’ which can occur in various organs or tissues and cause problems.
Different types of amyloidosis are named according to the type of amyloid protein which is produced. All begin with the initial ‘A’ which stands for amyloidosis, followed by another letter(s) which identifies the particular amyloid protein, for example: AL amyloidosis, AA amyloidosis and ATTR amyloidosis. In AL amyloidosis it is abnormal plasma cells in the bone marrow that produce the amyloid protein. In AL amyloidosis the amyloid proteins are light chains (the ‘L’ in ‘AL’ stands for ‘light chain’). Light chains are normally part of healthy antibodies, also known as immunoglobulins, produced by healthy plasma cells.