Monoclonal gammopathy of undetermined significance (MGUS) is a COMMON but typically HARMLESS blood disorder that occurs when there is overgrowth of identical plasma cells in bone marrow. Since it is the job of any given plasma cell to make a single (monoclonal) immunoglobulin protein, an increased population of identical bone marrow plasma cells may be detected by discovery of a monoclonal protein (M protein) in the blood stream.
MGUS becomes more prevalent with age. About 3 percent of people 50 and older and 5 percent of those 70 and older have M protein in their blood. The highest incidence is among adults age 85 and older. And MGUS is more common in men than in women.Sign & symptoms?
MGUS is usually found by chance during a blood test carried out for some other reason. The test, called a serum protein electrophoresis, can reveal abnormal proteins and unusual amounts of normal proteins.It doesn't usually cause any symptoms.
Occasionally people with MGUS have numbness or tingling in their hands and feet or problems with their balance. This may be due to damage to nerves caused by the paraprotein in the blood.
If these symptoms are troublesome or get worse you may be referred to a neurologist, who is a specialist in the nervous system.Developing Myeloma??
A doctor who detects monoclonal gammopathy may recommend further testing to determine what type of M protein the body is making and how much. The tests can also help a doctor rule out other medical conditions that may be causing production of M protein.
However, in a minority of cases, over time the cells in bone marrow that make M protein can accumulate, crowding out healthy cells. Or, the M protein can damage other tissues in the body. In this situation, treatment with chemotherapy may be necessary. The risk of developing a more serious condition increases the longer a person has had MGUS. There is about a 1 percent per year risk of developing a significant problem.During the first year after the diagnosis of MGUS is made, a patient should have regular follow-up with their hematologist/oncologist every three months. If the MGUS appears stable, follow-up appointments can be stretched to every six months for the second year. Thereafter, the MGUS should be followed at least annually to look for evidence of multiple myeloma or another blood cell cancer. With regular follow-up, development of multiple myeloma or another blood cell cancer can often be detected early, before many symptoms develop.