Test ID IGM Immunoglobulin M (IgM), Serum
Useful For
Detecting or monitoring of monoclonal gammopathies and immune deficiencies
Method Name
Nephelometry
Reporting Name
Immunoglobulin M (IgM), SSpecimen Type
SerumContainer/Tube:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 1 mL
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Serum | Refrigerated (preferred) | 28 days |
Ambient | 28 days | |
Frozen | 28 days |
Clinical Information
The gamma-globulin band as seen in conventional serum protein electrophoresis consists of 5 immunoglobulins. In normal serum, about 5% is immunoglobulin M (IgM).
Elevations of IgM may be due to polyclonal immunoglobulin production. Monoclonal elevations of IgM occur in macroglobulinemia.
Monoclonal gammopathies of all types may lead to a spike in the gamma-globulin zone seen on serum protein electrophoresis.
Decreased immunoglobulin levels are found in patients with congenital deficiencies.
Reference Values
0-<5 months: 26-122 mg/dL
5-<9 months: 32-132 mg/dL
9-<15 months: 40-143 mg/dL
15-<24 months: 46-152 mg/dL
2-<4 years: 37-184 mg/dL
4-<7 years: 37-224 mg/dL
7-<10 years: 38-251 mg/dL
10-<13 years: 41-255 mg/dL
13-<16 years: 45-244 mg/dL
16-<18 years: 49-201 mg/dL
≥18 years: 37-286 mg/dL
Cautions
Electrophoresis is usually required to interpret an elevated immunoglobulin class as polyclonal versus monoclonal. Immunofixation is usually required to characterize a monoclonal protein.
If there is a discrete M-peak, the monoclonal protein can be monitored with quantitative immunoglobulins. If immunoglobulin quantitation is used to monitor the size of a monoclonal protein which is contained in a back-ground of polyclonal immunoglobulins, however, changes in the immunoglobulin quantitation may reflect changes in the background immunoglobulins, and serum protein electrophoresis should therefore be used to monitor the monoclonal protein.
Day(s) Performed
Monday through Saturday; Continuously until 3 p.m.
Report Available
1 dayPerforming Laboratory

Test Classification
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82784