What are monoclonal gammopathies?

Monoclonal gammopathies are conditions in which abnormal proteins (antibodies) are found in the blood. These proteins are made from a small number of plasma cells in the bone marrow.

The most common condition linked with these abnormal proteins is monoclonal gammopathy of undetermined significance (MGUS). It's not cancer. However, people with MGUS may have a greater risk of getting serious diseases of the bone marrow and blood.

What causes monoclonal gammopathies?

The exact cause of MGUS is not known. Infection, immune system problems, and the environment may play a role. But experts have not found a clear link yet. Experts do know that the abnormal proteins are not caused by a certain diet or from eating dietary proteins.

Who is at risk for monoclonal gammopathies?

The chance of getting MGUS grows with age, but it's not common. It occurs more in people older than 50. Men and African Americans are at higher risk for MGUS. There is no risk for monoclonal gammopathies in first-degree family members. This means screening of siblings and children is not needed.

What are the symptoms of monoclonal gammopathies?

MGUS causes no symptoms. In fact, monoclonal protein in the blood is often found by accident when doing other routine blood work.

Most people who have abnormal proteins in their blood will never get worse. But in some cases, these illnesses can develop:

• Multiple myeloma

• Non-Hodgkin lymphoma

• Plasma cell leukemia

• Primary amyloidosis

• Solitary plasmacytoma

• Waldenstrom macroglobulinemia

How are monoclonal gammopathies diagnosed?

Once abnormal proteins are found in the blood, more testing is needed. A blood screening and sometimes a urine screening is recommended. This is often done with a lab test called protein electrophoresis. This test separates proteins based on their size and other factors. Depending on the results of those tests, more testing may be done. 

How are monoclonal gammopathies treated?

MGUS does not usually cause symptoms, so it doesn’t need to be treated. Since MGUS may lead to a more serious condition, regular monitoring and checkups are recommended throughout your life. This often includes regular physical exams and blood tests. This will help find problems as early as possible.

Key points about monoclonal gammopathies

• Monoclonal gammopathies are conditions in which abnormal proteins are found in the blood.

• The most common condition linked with these abnormal proteins is monoclonal gammopathy of undetermined significance (MGUS).

• MGUS usually causes no symptoms. Diagnosis is often done with a lab test called protein electrophoresis.

• Treatment is not needed unless symptoms develop.

• MGUS may lead to a more serious condition. So checkups may be recommended throughout your life to find problems as early as possible.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new directions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are and when they should be reported.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions, especially after office hours or on weekends.