Test Code LAB72 Immunoglobulin M (IgM)
Useful For
- Detecting acute infection. IgM is the first specific antibody to appear in the serum after infection. After the infection has subsided, IgM levels sink at a relatively rapid rate compared to IgG.
- The differential diagnosis of acute and chronic infections by comparing specific IgM and IgG titers. If IgM is prevalent the infection is acute, whereas if IgG predominates the infection is chronic (e.g. rubella, viral hepatitis).
- Increased polyclonal IgM levels are found in viral, bacterial, and parasitic infections, liver diseases, rheumatoid arthritis, scleroderma, cystic fibrosis and heroin addiction. Monoclonal IgM is increased in Waldenström’s macroglobulinemia.
- Increased loss of IgM is found in protein‑losing enteropathies and in burns.
Methodology
Immunoturbidimetric
Performing Laboratory
Bozeman Health Laboratory Services
Specimen Requirements
Specimen Type: Plasma or serum
Container/Tube: Light-green top (lithium heparin gel), red top, or gold top
Specimen Volume: 1 mL
Specimen Minimum Volume: 0.5 mL
Specimen Transport Temperature
Ambient/Refrigerated
Specimen Stability
Specimen Type | Temperature | Time |
---|---|---|
Plasma or Serum | Ambient | 2 months |
Refrigerated | 4 months | |
Frozen | 6 months |
Reference Values
Adults: 50-300 mg/dL
During childhood and adolescence, reference ranges for IgM are dependent on age and gender:
Age | IgM mg/dL | |
---|---|---|
0-4 months | 14-142 mg/dL | |
4 months-8 months | 24-167 mg/dL | |
8 months-1 year | Male | 35-200 mg/dL |
Female | 34-242 mg/dL | |
1 year-3 years | Male | 41-200 mg/dL |
Female | 41-242 mg/dL | |
3 years-17 years | Male | 47-200 mg/dL |
Female | 56-242 mg/dL | |
≥ 17 years | 50-300 mg/dL |
Day(s) Test Set Up
Monday through Sunday
Test Classification and CPT Coding
82784