Immunoglobulins are also known as antibodies. They are made by plasma cells (white blood cells).

Plasma cells make immunoglobulins, which are also known as antibodies. If you have an infection, your bone marrow makes more plasma cells and immunoglobulins. The immunoglobulins travel in your blood and help to fight viruses or bacteria in the body.

If you have myeloma, the myeloma cells make an abnormal immunoglobulin which cannot fight infection. This is sometimes called a paraprotein or M protein.

You may also make less normal immunoglobulins than usual. This also makes it harder for your body to fight infection.

There are 5 immunoglobulins. These are IgA, IgD, IgE, IgG or IgM. The ‘Ig’ is short for immunoglobulin.

Different types of myeloma are named after the abnormal immunoglobulin (paraprotein) the myeloma cells make. The most common type of myeloma is IgG.

Immunoglobulins are made up of both:

  • 2 matching and shorter light chains (proteins)
  • 2 matching and longer heavy chains.

There are 2 types of light chain. They are called kappa and lambda.

There are 5 types of heavy chain called A, D, E, G and M. Immunoglobulins are named after the type of heavy chain they have.

An immunoglobulin:

An immunoglobulin

Blood tests


You have blood tests to find the abnormal immunoglobulin (paraprotein) to help diagnose myeloma. You also have regular blood tests to measure the paraprotein level. This can tell if the treatment you are having is helping to get the myeloma into remission. Your also have these tests after treatment to make sure the myeloma is not active.