Checks if you have MGUS

The main guidance

The International Myeloma Working Group (IMWG) published consensus guidelines for monitoring MGUS in 2010. (IMWG, 2010) The European Myeloma Network published recommendations on diagnosis and follow-up in 2014. (European Myeloma Network, 2014) In the UK, the British Society for Haematology (BSH) and the UK Myeloma Forum published a Good Practice Paper in 2023 covering diagnosis, risk groups and management, and discussing the potential for targeted population screening. (BSH, 2023 (abstract)) The American Cancer Society lists MGUS as a risk factor for multiple myeloma. (American Cancer Society)

No population screening

There is no routine screening test for MGUS in people without symptoms. The European Myeloma Network says screening the general population is not recommended outside of studies. It also says it is unknown whether finding a monoclonal gammopathy early helps relatives of people with MGUS, myeloma or Waldenström macroglobulinemia, and recommends screening them only as part of a research protocol. (European Myeloma Network, 2014) The IMWG consensus says the abnormal protein is usually found by chance. (IMWG, 2010)

Risk groups

Both the IMWG and the European Myeloma Network use the Mayo Clinic risk model, which has three risk factors: an abnormal protein (M protein) level of 15 g/L or more, an IgA or IgM type (rather than IgG) and an abnormal serum free light chain ratio. The 20-year risk of progression was 58 percent with all three, 37 percent with two, 21 percent with one and 5 percent with none. (IMWG, 2010)(European Myeloma Network, 2014) The IMWG consensus describes low-risk MGUS as an M protein below 15 g/L, IgG type and a normal free light chain ratio (0.26 to 1.65). (IMWG, 2010)

Tests and checks the guidance lists

Blood and urine tests

At first diagnosis, the IMWG consensus recommends a complete history and physical exam, a complete blood count, serum calcium and creatinine (a kidney test) and a test for protein in the urine, with urine electrophoresis and immunofixation if protein is found. It says serum protein electrophoresis should be repeated 3 to 6 months later. (IMWG, 2010) The European Myeloma Network says follow-up consists of a careful history, physical exam and lab tests: the M protein level, complete blood count, creatinine and calcium. It recommends that people with intermediate or high-risk MGUS are seen at 6 months and then every year, and people with low-risk MGUS at 6 months and then every 1 to 2 years. (European Myeloma Network, 2014) It recommends follow-up at 6 months and every year after for light-chain MGUS, because of a considerable risk of kidney disease, and says people with raised free light chains should also have NT-proBNP and urine albumin measured during follow-up. (European Myeloma Network, 2014) MedlinePlus explains that protein electrophoresis measures the protein types in the blood (MedlinePlus) and that a free light chain test compares kappa and lambda light chains as a ratio. (MedlinePlus lab tests) See complete blood count results and kidney test results.

Bone marrow tests and bone imaging

For low-risk MGUS, the IMWG consensus says a bone marrow test or skeletal X-rays are not routinely needed if the exam, blood count, creatinine and calcium fit MGUS. It says a bone marrow test is needed at the start for an M protein above 15 g/L, an IgA or IgM type or an abnormal free light chain ratio, and always with unexplained anemia, kidney problems, high calcium or bone lesions. It recommends a CT scan of the abdomen for IgM MGUS. (IMWG, 2010) The European Myeloma Network says imaging is not routinely recommended for an IgG M protein of 15 g/L or less or an IgA M protein of 10 g/L or less without bone pain. For other people with MGUS it says imaging should be considered: a skeletal survey for non-IgM types, for which low-dose whole-body CT may be a good alternative, and a CT of the chest, abdomen and pelvis for IgM MGUS. It does not recommend whole-body MRI or PET/CT outside trials. (European Myeloma Network, 2014)

Bone density

The European Myeloma Network says people with MGUS have a higher risk of osteoporosis and fractures, more often in the spine and trunk than in the arms and legs, and that it may be appropriate to check for bone loss with a DXA scan, especially when other osteoporosis risk factors are present. (European Myeloma Network, 2014) It also recommends tests to rule out myeloma in people with a monoclonal gammopathy and osteoporosis, especially men and women before menopause. (European Myeloma Network, 2014) See how often to have a bone density test.

Routine age-based screening

These checks are added to, not instead of, the routine screenings for your age and sex; see screenings by age and gender and preventive screenings for older adults. The IMWG consensus says people with low-risk MGUS should be followed for other health problems that are far more likely to affect survival than MGUS progression. (IMWG, 2010) The European Myeloma Network says many people can have MGUS follow-up in primary care. (European Myeloma Network, 2014)

Where they differ:

• How often for low-risk MGUS. The IMWG consensus says every 2 to 3 years after a stable 6-month test; the European Myeloma Network says every 1 to 2 years after 6 months, or only lab tests when symptoms develop. (IMWG, 2010)(European Myeloma Network, 2014)
• Stopping follow-up. The IMWG consensus says follow-up for intermediate and high-risk MGUS is yearly for life; the European Myeloma Network says no follow-up can be considered for older people or people with serious other illness and a short life expectancy. (IMWG, 2010)(European Myeloma Network, 2014)
• Bone marrow test for IgA MGUS. The IMWG consensus links a bone marrow test to having any risk factor; the European Myeloma Network says it should be part of the workup for all IgA and IgM types. (IMWG, 2010)(European Myeloma Network, 2014)
• Bone imaging. The IMWG consensus mentions skeletal X-rays and a CT of the abdomen for IgM MGUS; the European Myeloma Network sets protein cut-offs for imaging and suggests low-dose whole-body CT as an alternative to skeletal X-rays. (IMWG, 2010)(European Myeloma Network, 2014)

Your doctor decides what your result means for you.

Questions people ask

Should everyone be screened for MGUS?

No. The European Myeloma Network says screening the general population is not recommended outside of studies, and that screening relatives of people with MGUS or myeloma should only be done as part of a research protocol. (European Myeloma Network, 2014)

How is MGUS usually found?

Usually by chance. The IMWG consensus says the abnormal protein is usually found when a blood test is done for another reason, and the European Myeloma Network says it is often found when serum protein electrophoresis is requested for symptoms such as tiredness, repeated infections or back pain. (IMWG, 2010) (European Myeloma Network, 2014)

How often are blood tests repeated?

The IMWG consensus says serum protein electrophoresis should be repeated 3 to 6 months after MGUS is first found. After that it depends on the risk group: every 2 to 3 years for low-risk MGUS if stable, and yearly for life for intermediate and high-risk MGUS. (IMWG, 2010)

What makes MGUS low risk?

The IMWG consensus uses three factors: an abnormal protein level below 15 g/L, the IgG type and a normal free light chain ratio. With none of the three risk factors, the 20-year risk of progression was 5 percent; with all three it was 58 percent. (IMWG, 2010)

Do I need a bone density scan?

The European Myeloma Network says that, because MGUS raises the risk of osteoporosis and fractures, it may be appropriate to check for bone loss with a DXA scan, especially when other osteoporosis risk factors are present. (European Myeloma Network, 2014)

Related

• Checks if you have primary hyperparathyroidism
• Complete blood count results
• Kidney test results
• How often to have a bone density test
• Blood tests by age
• Screenings if you have Sjögren's disease
• Preventive screenings for older adults
• Screenings by age and gender
• Questions to ask your doctor