Amyloidosis is the name for a group of rare, serious conditions caused by a build-up of an abnormal protein called amyloid in organs and tissues throughout the body. See your GP if you have any of the symptoms of amyloidosis and are worried, (see symptoms section below).
The build-up of amyloid proteins (deposits) caused by amyloidosis can make it difficult for the organs and tissues to work properly. Without treatment, this can lead to organ failure.
This page focuses on AL amyloidosis (previously known as primary amyloidosis), which is the most common type, and on ATTR amyloidosis (transthyretin-related hereditary amyloidosis). ATTR amyloidosis is now being diagnosed much more often than in the past.
For information on the rarer types of amyloidosis, visit the UCL National Amyloidosis Centre Patient Information Site.
Signs and symptoms of AL amyloidosis
The symptoms of AL amyloidosis depend on which tissues and organs are affected.
Most people with AL amyloidosis have a build-up of amyloid proteins (amyloid deposits) in their kidneys, and are at risk of kidney failure.
Symptoms of kidney failure include:
- swelling, often in the legs, caused by fluid retention (oedema)
- foamy or frothy urine, which may be caused by excess protein in your urine
- loss of appetite
Deposits of amyloid in the heart can cause the muscles to become stiffer, making it more difficult to pump blood around the body.
This may result in heart failure, which can cause symptoms such as:
Amyloid proteins can also build up in other organs and tissues, like the liver, spleen, nerves or digestive system.
This means you may have any of the following symptoms:
- feeling lightheaded or fainting, particularly after standing or sitting up
- numbness or a tingling feeling in the hands and feet (peripheral neuropathy)
- nausea, diarrhoea or constipation
- numbness, tingling and pain in the wrist, hand and fingers (carpal tunnel syndrome)
- an enlarged tongue
AL amyloidosis doesn't affect the brain, so it doesn't cause any problems with memory or thinking, for example.
See your GP if you have any of the above symptoms and are worried. Your doctor will carry out investigations, or refer you to hospital, in order to diagnose what is causing your symptoms.
The symptoms are not specific to amyloidosis, and other conditions can cause similar symptoms (see ‘Diagnosing AL amyloidosis’ below).
In some cases, AL amyloidosis can be linked to a type of bone cancer called multiple myeloma.
Cause of AL amyloidosis
AL amyloidosis is caused by an abnormality in certain cells found in the bone marrow, called plasma cells.
The abnormal plasma cells produce abnormal forms of light chain proteins, which enter the bloodstream and can form amyloid deposits.
The abnormal light chains in patients with AL amyloidosis clump together into thread-like strings (amyloid fibrils) that the body can't clear away easily.
Over time, amyloid fibrils build up as AL amyloid deposits in tissues and organs. This gradually stops them functioning properly, causing the many symptoms of AL amyloidosis.
Unlike some other types of amyloidosis, AL amyloidosis isn't inherited, so a person with the condition can't pass it on to their children.
Treating AL amyloidosis
There isn't currently a cure for amyloidosis. The amyloid deposits can't be directly removed.
But there are treatments to stop more of the abnormal proteins being produced and treat your symptoms.
These treatments can give your body time to gradually clear the deposits before they build up again, and can help prevent organ damage.
In most cases, the treatment will involve having chemotherapy. Chemotherapy damages abnormal bone marrow cells and stops them producing the abnormal proteins that form amyloid deposits.
Your doctor may also discuss using other treatments, such as medication and a stem cell transplant.
After chemotherapy, you'll need regular check-ups every 6 to 12 months to look for signs of the AL amyloidosis returning (relapsing). If you do relapse at any stage, you may need to start chemotherapy again.
Diagnosing AL amyloidosis
Diagnosing AL amyloidosis can be hard, as the symptoms are often vague and not specific.
A small tissue sample (a biopsy) can be taken from the affected part of your body. Your doctor will talk to you about how this will be done.
The biopsy will be examined under a microscope in a laboratory to see if there are any amyloid deposits in it.
The NHS National Amyloidosis Centre in London also offers a type of body scan called a SAP scan.
This involves being injected with a small amount of a radio-labelled blood protein called serum amyloid P component (SAP) before being scanned with a special camera that detects the radioactivity.
The radio-labelled protein sticks to any amyloid deposits in your body, which highlights the areas of your body that are affected.
ATTR amyloidosis is caused by amyloid deposits from abnormal versions of a blood protein called transthyretin (TTR).
ATTR amyloidosis can run in families and is known as hereditary ATTR amyloidosis. People with hereditary ATTR amyloidosis produce abnormal TTR proteins throughout their lives, which can form amyloid deposits. These usually affect the nerves or the heart, or both.
Another type of ATTR amyloidosis isn't hereditary. This is called wild type ATTR amyloidosis, or senile systemic amyloidosis. In this condition, the amyloid deposits mainly affect the heart and can also cause carpal tunnel syndrome in some people.
Hereditary ATTR amyloidosis may cause symptoms at any age from about the age of 30. The symptoms of wild type ATTR amyloidosis usually only appear after around the age of 65. In recent years, as a result of new imaging techniques it's become clear that wild type ATTR amyloidosis may be far more common than thought.
ATTR amyloidosis can be diagnosed by:
- taking a sample of the affected tissues (tissue biopsy)
- genetic testing
- heart scans – such as an echocardiogram, a cardiac MRI or a special type of scan called a DPD
More useful links
The information on this page has been adapted from original content from the NHS website.
For further information see terms and conditions.