What is monoclonal gammopathy of undetermined significance (MGUS)? Learn about symptoms, risk factors, and treatment
Monoclonal gammopathy of undetermined significance (MGUS) is a condition where your body creates an abnormal protein within your blood tissue.
In most cases, MGUS does not cause problems and requires no treatment. However, in some cases, the disorder may be caused by certain diseases and lead to more serious medical conditions, requiring frequent monitoring of monoclonal protein levels in the blood.
If MGUS comes with complications, treatment will vary depending on the underlying cause, often involving radiotherapy and chemotherapy to kill the defective plasma cells and stop the abnormal protein buildup in the body.
What is monoclonal gammopathy?
Monoclonal gammopathy is not a single disorder but a group of disorders. In this condition, there is abnormal activation of plasma cells and excessive buildup of gamma globulin.
Plasma cells are a type of white blood cell inside the bone marrow that produces antibodies, which protect the body against pathogens. In monoclonal gammopathy, there is an excessive and abnormal proliferation of these plasma cells, causing increased production of an antibody called IgG (immunoglobulin G), which are chemical proteins that are all replicas of each other. These are called monoclonal proteins or M proteins.
What are the risk factors for monoclonal gammopathy?
Although the exact cause causing the proliferation of the plasma cells is not known, potential risk factors include:
- Age: Average age at diagnosis is over age 60.
- Race: Africans and African Americans are likely to be affected.
- Sex: MGUS is more common in men.
- Family history: Positive family history increases risk of developing the condition.
What are the signs and symptoms of monoclonal gammopathy?
MGUS is typically not associated with any significant signs and symptoms. However, it can lead to serious complications that may then present with their respective symptoms, such as:
- Anemia due to fewer red blood cells (RBC)
- Weakness due to lower RBC
- Repeated infections due to abnormal antibodies and fewer white blood cells (WBC)
- Increased bruising due to fewer platelets
- Weight loss
Due to abnormal M protein depositions in different organs, symptoms may include:
- Tingling and numbness on hands (deposition of protein in the nerves)
- Vision problems (deposition of proteins in the lens and cornea)
- Mental changes (deposition of proteins in the brain)
How is monoclonal gammopathy diagnosed?
As there is an excess of M proteins in the blood with MGUS, these proteins are also secreted out from the body via urine. Thus, electrophoresis of blood or urine can separate the various proteins present, and abnormal levels of M protein can be easily detected.
In advanced cases, depositions can also be detected in various organs through a biopsy.
What are the complications of monoclonal gammopathy?
The following diseases can develop as a sequela of MGUS: