Related Subjects:
|Hypercalcaemia
|Multiple Myeloma
|Extramedullary Plasmacytoma
|Smouldering Myeloma
|MGUS
|Waldenstrom Macroglobulinaemia
|Oncological emergencies
One of the key differentiating features between (MGUS) and myeloma is
the absence of complications such as immune paresis, hypercalcemia and
bone pain, renal disease. Monoclonal protein level < 30 g/L
About
- Monoclonal gammopathy of undetermined significance MGUS
- A paraproteinaemia (monoclonal protein) which may progress to Myeloma
- Patients have a serum Monoclonal protein < 30 g/l
- It may take up to 10 years to develop Myeloma
Epidemiology
- It is asymptomatic and extremely common
- Seen in 1% of people >25 years, 3% >70 years, and 10% >80 years of age
- MGUS to Myeloma only happens in 25%
Differential of Monoclonal band
- Multiple Myeloma; Bone pain, lytic lesions, high calcium, nephropathy
- Lymphoma: Lymphadenopathy/large liver and spleen
- Chronic Lymphocytic Leukaemia (CLL) : elevated lymphocytes
- Monoclonal gammopathy Undetermined significance
Clinical
- None due to MGUS typically
- No bone pain or risk of infections
- 10-30% of patients have a demyelinating neuropathy
In MGUS there is no
- Bence-Jones proteinuria
- Lytic bone lesion
- Hypercalcaemia
- Renal insufficiency
- Anaemia
- Monoclonal Ig level >20 g/l
- Percentage plasma cells on bone marrow examination >4%
- Abnormal level of other Ig or immunoparesis
Risk of progression
- Overall, approximately 1% of patients with MGUS progress to myeloma each year.
- Risk factors associated with a higher chance of progressing to symptomatic disease are listed below.
Assess 3 factors
- Paraprotein level >15 g/L +1 point
- Abnormal serum free light chain ratio +1 point
- non-IgG protein (i.e., IgA, IgE) +1 point
Number of Factors
- Risk of progression at 20 years
- No abnormal factors 5%
- 1 factor 21%
- 2 factors 37%
- 3 factors 58%
Managing a Paraprotein
Management
- Manage those at low risk of progression (i.e., = 2 factors) in general practice.
- paraprotein level >15 g/L 1 point
- abnormal SFLC ratio 1 point
- non-IgG protein (i.e., IgA, IgM) 1 point
- Review every 6 to 12 months:
- Ask about weight loss, bone pain, and night sweats.
- Check for lymphadenopathy, hepatosplenomegaly.
- Check FBC, calcium, creatinine, albumin, SPE with paraproteinlevels.
- Request haematology assessment if:
- lymphadenopathy.
- significant rise in the level of monoclonal protein over a few months i.e., >25% provided the absolute minimum rise is >5 g/L.
- New significant cytopenias (anaemia, neutropenia, thrombocytopenia).
- high risk of progression to myeloma.
- renal failure or development of bone pain.
- Where appropriate, written advice may be available