Amyloidosis Dr Rob Hicks Amyloidosis is not a common condition. However, since it can damage organs of the body causing them to malfunction, it needs to be considered when things start to go wrong.

In this article

What is it? Who's affected?

What are the symptoms? How is it diagnosed?

What's the treatment?

Amyloid is the term used to describe a deposit of protein folded in a particular, abnormal way. When these misfolded proteins deposit in an organ in the body - for example, the heart, the kidneys or nerves - the condition is called amyloidosis.

The collection of these abnormal proteins interferes with the normal functioning of the organ affected.

Since there are many different proteins that may form amyloid, there are also many different types of amyloidosis.

The most common in the UK is AL amyloidosis, also known as primary amyloidosis. In this form, abnormal cells in the bone marrow produce abnormal antibody proteins that form the amyloid.

In AA, or secondary amyloidosis, it occurs as a result of an inflammatory condition, most often rheumatoid arthritis, due to the long-term overproduction of an otherwise normal inflammatory protein.

There are also some rarer hereditary forms.

Amyloidosis is more common in older people and is also slightly more common in men than in women.

It's the accumulation of amyloid in an organ that causes the organ to malfunction and symptoms to develop. However, amyloid may accumulate in organs of the body for many years before problems arise and any of the resultant symptoms are noticed.

The symptoms that a person experiences depend on which organ is affected.

If amyloid is deposited in the kidneys, chronic kidney failure may occur. This in turn causes symptoms such as fluid retention, tiredness, lethargy, weakness and loss of appetite.

When amyloid is deposited in the heart it may become enlarged and unable to pump blood effectively around the body. This results in the development of chronic heart failure with symptoms of breathlessness and fluid retention.

Amyloidosis is often difficult to diagnose. To confirm the diagnosis, a biopsy is taken from an affected part of the body and the sample of tissue is examined under the microscope. Abnormal protein deposits indicate amyloidosis.

It isn't always easy to treat amyloidosis. In cases where it's secondary to another problem (AA amyloidosis), such as rheumatoid arthritis, treating that may stop the progress of amyloidosis or may even reverse it.

In cases of primary amyloidosis (AL amyloidosis), chemotherapy drugs may be given to suppress production of new amyloid and cause regression of existing amyloid deposits.

Occasionally, transplantation of a damaged organ is necessary. However, even after this has been carried out the new organ may become affected by amyloidosis.

This article was last medically reviewed by Dr Rob Hicks in October 2007