Sign in →

Test Code IGM Immunoglobulin M (IgM), Serum

Additional Codes

Mayo Test ID
IGM

Reporting Name

Immunoglobulin M (IgM), S

Useful For

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

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

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.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

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

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

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

LOINC Code Information

Test ID Test Order Name Order LOINC Value
IGM Immunoglobulin M (IgM), S 2472-9

 

Result ID Test Result Name Result LOINC Value
IGM Immunoglobulin M (IgM), S 2472-9

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.

Interpretation

Increased serum immunoglobulin concentrations occur due to polyclonal or oligoclonal immunoglobulin proliferation in hepatic disease (eg, hepatitis, liver cirrhosis), connective tissue diseases, acute and chronic infections, as well as in the cord blood of neonates with intrauterine and perinatal infections.

 

Elevation of IgM may occur in monoclonal gammopathies such as macroglobulinemia, primary systemic amyloidosis, monoclonal gammopathy of undetermined significance, and related disorders.

 

Decreased levels are found in patients with primary or secondary immune deficiencies.

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.

Reject Due To

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Method Name

Nephelometry

Forms

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

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days