Monoclonal gammopathy of undetermined significance (MGUS)



What is monoclonal gammopathy of undetermined significance (MGUS)?

Monoclonal gammopathy of undetermined significance (MGUS) is a condition in which an abnormal protein — known as monoclonal protein or M protein — is in your blood. The protein is produced in a type of white blood cell (plasma cells) in your bone marrow.

MGUS usually causes no problems. But sometimes it can progress over years to other disorders, including some forms of blood cancer.

It’s important to have regular checkups to closely monitor monoclonal gammopathy so that if it does progress, you get earlier treatment. If there’s no disease progression, MGUS doesn’t require treatment.

How common is monoclonal gammopathy of undetermined significance (MGUS)?

In general, monoclonal gammopathy of undetermined significance (MGUS) occurs in more than 5% of people older than 70, but it does not cause significant health problems unless it progresses to myeloma or a related serious B-cell disorder. Please discuss with your doctor for further information.


What are the symptoms of monoclonal gammopathy of undetermined significance (MGUS)?

People with monoclonal gammopathy generally don’t experience signs or symptoms. Some people may experience a rash or nerve problems, such as numbness or tingling. MGUS is usually detected by chance when you have a blood test for another condition.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes monoclonal gammopathy of undetermined significance (MGUS)?

MGUS occurs when abnormal plasma cells produce M protein. The protein isn’t harmful for most people. But if too much M protein accumulates, it crowds out healthy cells in your bone marrow and can damage other tissues in your body.

The precise cause of accumulating M protein isn’t known. Genetic changes and environmental triggers appear to play a role.

Risk factors

What increases my risk for monoclonal gammopathy of undetermined significance (MGUS)?

There are many risk factors for monoclonal gammopathy of undetermined significance (MGUS), such as:

  • The average age at diagnosis is 70 years.
  • Africans and African-Americans are more likely to experience MGUS than are white people. The incidence in other races isn’t clear.
  • MGUS is more common in men.
  • Family history. You may have a higher risk of MGUS if other people in your family have the condition.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is monoclonal gammopathy of undetermined significance (MGUS) diagnosed?

MGUS is usually detected during blood tests for another condition, such as a certain nerve disorder (peripheral neuropathy). The blood tests can show abnormal proteins as well as unusual amounts of normal proteins.

If your doctor detects monoclonal gammopathy, further testing may be recommended to determine which M protein your body is making and how much is being made.

To rule out other causes of elevated protein levels, your doctor might recommend:

  • Additional blood tests. Tests to count the blood cells in your blood (complete blood count), to look for a decline in kidney function (serum creatinine test) and to determine the amount of calcium in your blood (serum calcium test) can help rule out conditions such as multiple myeloma.
  • Urine tests. These tests can determine if abnormal protein is being released into your urine, and assess any resulting kidney damage. You’ll likely need to collect your urine for 24 hours.
  • Imaging tests. If you are experiencing bone pain, your doctor might recommend an MRI or CT-positron emission tomography (PET) scan. The images can help your doctor find bone abnormalities related to MGUS.
  • Bone marrow test. A hollow needle removes a portion of your bone marrow from the back of one of your hipbones. The bone marrow is analyzed to determine its percentage of plasma cells. Bone marrow testing is generally done only when you’re at risk of developing a more serious disease or if you have unexplained anemia, kidney failure, bone lesions or high calcium levels.

How is monoclonal gammopathy of undetermined significance (MGUS) treated?

MGUS doesn’t require treatment. But your doctor is likely to recommend periodic checkups to monitor your health, probably starting six months after your diagnosis.

Watchful waiting

If you are at high risk of developing a more-serious condition, your doctor may recommend more frequent checkups so that any progression can be diagnosed and treatment started as soon as possible.

Your doctor is likely to watch for the development of signs and symptoms including:

  • Pain
  • Fatigue or weakness
  • Unintentional weight loss
  • Fever or night sweats
  • Headache, dizziness, nerve pain, or changes in vision or hearing
  • Bleeding
  • Anemia or other blood abnormalities
  • Swollen lymph nodes, liver or spleen
  • Heart and kidney problems
  • Medications

If you have osteoporosis, your doctor might recommend a medication (bisphosphonate) to increase bone density. Examples include alendronate (Binosto, Fosamax), risedronate (Actonel, Atelvia), ibandronate (Boniva) and zoledronic acid (Reclast, Zometa).

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage monoclonal gammopathy of undetermined significance (MGUS)?

The following lifestyles and home remedies might help you cope with monoclonal gammopathy of undetermined significance (MGUS):

  • Stick to your checkup schedule. Diagnosing a serious condition, such as cancer, in the early stages may improve your treatment outcomes.
  • Follow a healthy lifestyle. You can reduce your risk of developing conditions unrelated to MGUS by eating a variety of fruits and vegetables, getting enough exercise and sleep, and reducing stress.

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: November 22, 2017 | Last Modified: November 22, 2017

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