What is myeloma?

The role of plasma cells is to make antibodies. These are proteins that circulate in your blood, finding and killing germs such as viruses, bacteria and fungus which cause infections.

In myeloma, something goes wrong with your plasma cells. They start making antibodies that don’t work properly and can’t kill germs effectively. So you may have infections that last longer and are more frequent than usual.

These abnormal plasma cells – or myeloma cells – also grow more quickly than they should. They crowd your bone marrow so there isn’t enough room for other blood cells to be made. This leads to other symptoms of myeloma, such as anaemia, which can make you feel tired.

Antibodies are complex Y-shaped proteins, made up of chemical structures called heavy chains and light chains. You may also hear them called immunoglobulins.

The abnormal antibodies produced by myeloma cells are known as paraproteins. They are sometimes called other names like M-protein, M-band or M-spike – these terms all mean the same thing. If there is paraprotein in your blood, it may be a sign that you have myeloma.

Most people with a diagnosis of myeloma will have regular blood tests to monitor the level of paraprotein in their blood. But in some types of myeloma, the myeloma cells don’t produce paraprotein. So it will be monitored in other ways.

There are different types of myeloma which can be identified by diagnostic tests. The type of myeloma you have depends on the type of paraprotein and light chains in your blood.

Myeloma cells make only one type of paraprotein, and this varies from person to person. There are five types of paraprotein: G, A, D, E and M. IgG (immunoglobulin G) is the most common type, IgA less common. The others are very rare.

There are two types of light chains: kappa and lambda.

Based on this, you may be told that you have, for instance, IgG kappa myeloma.

After genetic tests, you may also be told that you have a particular genetic subtype of myeloma. This information gives doctors a better idea of how the myeloma might progress (your prognosis). In future, we hope there will be targeted treatments for different genetic subtypes of myeloma.

Myeloma can be smouldering or active.

People with smouldering myeloma don’t have any symptoms of myeloma. They are often diagnosed by chance following a blood test for something else.

Smouldering myeloma is also called asymptomatic myeloma because of the lack of symptoms.

• If you have active myeloma, you will usually have some symptoms and will normally start treatment quite quickly.
• If you have smouldering myeloma, you may not need treatment for a while, or perhaps never. You will be monitored regularly until your doctor recommends you start treatment. This approach is called active monitoring or watch and wait.

One in five people with myeloma (20%) have light chain myeloma. In light chain myeloma, the myeloma cells don’t produce whole paraproteins, just the light chain parts. Regular tests will monitor the level of light chains in the blood, and sometimes in the urine.

If you have light chain myeloma, you may be told you have either kappa or lambda light chain myeloma.

Find out more about tests for myeloma.

Around three people in a hundred with myeloma (3%) have non-secretory myeloma. In this type of myeloma, the myeloma cells don’t produce any paraprotein or light chains.

Sometimes, the myeloma cells produce a very small amount of paraprotein or light chains. This is known as oligo-secretory myeloma.

Non-secretory and oligo-secretory myeloma are hard to detect using blood tests. That’s why doctors and research scientists sometimes describe these types of myeloma as “non-measurable” myeloma. Tests may look normal, or almost normal, although there may be other changes seen in the blood.

If this is the case for you, then blood and urine tests may not be enough to check on your condition, so your doctor will monitor you using bone marrow samples and scans.

Myeloma is often referred to as multiple myeloma because it affects the bone marrow in more than one place and can affect other parts of the body.

Multiple myeloma and myeloma are different names for the same disease.

We don’t fully understand what causes myeloma, but we know that there are some things that make it more likely to develop myeloma. These are called risk factors.

The main risk factors for myeloma are: