Types of Myeloma

There are various types of myeloma. Understanding the different types of your disease can help you make informed decisions about your treatment and necessary lifestyle adjustments.  

What Is Immunoglobulin​?

The bone marrow produces plasma cells, which secrete antibodies that fight infections. These antibodies are known as immunoglobulins (Ig) and have a Y-shaped structure that consists of:

• Two light protein chains (light chains)
• Two long protein chains (heavy chains)

There are two types of light chains called lamba and kappa. The Greek symbol k refers to kappa and the symbol λ refers to lambda. There are also five types of heavy protein chains, namely G, A, D, E, and M.

Immunoglobulins are named after the type of heavy chain they have. This means there are five possible types of immunoglobulins, namely IgG, IgA, IgD, IgE and IgM.

Subtypes of immunoglobulins

While there are five main types of immunoglobulin, there are also various subtypes, including: 

The Difference Between Monoclonal and Polyclonal Proteins

Polyclonal proteins are normal immunoglobulins (antibodies) made by healthy plasma cells in response to different threats, such as bacteria or viruses. These antibodies are diverse, with different heavy and light chain combinations, allowing the immune system to recognize and fight a wide range of infections.

In contrast, monoclonal proteins are abnormal antibodies made by myeloma cells, which are cancerous plasma cells. Unlike polyclonal proteins, monoclonal proteins are identical copies of a single immunoglobulin. They typically have one specific type of heavy chain (like IgG or IgA) and one type of light chain (kappa or lambda).

Why Monoclonal Proteins Matter in Myeloma

In multiple myeloma, the overproduction of monoclonal protein can cause several problems:

• Increased risk of infection because these proteins don’t fight germs effectively.
• Organ damage, particularly to the kidneys, because the abnormal proteins can accumulate in tissues.
• Bone damage – the clonal plasma cells cause an imbalance of cells that produce bone and break down bone.

Tests to measure monoclonal protein levels help doctors monitor myeloma and determine if the disease is stable or progressing.

Are There Different Types of Myeloma?

There are different myeloma types and they are named after abnormal immunoglobulins produced. The most common type of multiple myeloma is IgG kappa. Other types include:

• Light chain myeloma: It can happen that myeloma cells only produce Ig with light chains and no heavy chains. This is referred to as light chain myeloma or Bence-Jones myeloma and affects about 15% to 20% of patients.
• Non-secretory myeloma: This type of myeloma produces very little or no monoclonal protein of any type. This myeloma type affects about 1% to 3% of patients.
• IgM myeloma: This is a less common subtype of myeloma characterized by the production of IgM immunoglobulin. Clonal IgM immunoglobulin is more often associated with another protein disorder called Waldenstrom’s Macroglobulinemia (see below). For more information, contact IWMF.com.

Your doctor will order tests to identify your type of myeloma. It's important to know which type you have as you will be able to better understand your test results.You will be able to determine if your level of monoclonal protein is stable, increasing, or decreasing.

Other Considerations

See the IMF's Patient Handbook if you have been diagnosed with any of the following:

• AL amyloidosis
• Light chain deposition disease (LCDD)
• Waldenström's macroglobulinemia
• POEMS syndrome

Find Out More About Multiple Myeloma

The International Myeloma Foundation offers extensive resources on multiple myeloma. To find out more about this condition, browse our free resource library or call our InfoLine to speak with a compassionate expert about the disease. 

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