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Test ID IGM Immunoglobulin M (IgM), Serum


Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Forms

If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.

Secondary ID

8158

Useful For

Detecting or monitoring of IgM monoclonal gammopathies and IgM-related immune deficiencies

Method Name

Nephelometry

Reporting Name

Immunoglobulin M (IgM), S

Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  14 days

Clinical Information

The gamma globulin band as seen in conventional serum protein electrophoresis consists of 5 immunoglobulins. In normal serum, about 5% is 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 that is contained in a background of polyclonal immunoglobulins, 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.

 

Results determined by assays using different manufacturers or methods may not be comparable.

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US 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

NY State Approved

Yes