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HelpTest Code B2M Beta-2-Microglobulin, Serum
Reporting Name
Beta-2-Microglobulin, SUseful For
Prognosis assessment of multiple myeloma
Evaluation of renal tubular disorders
Testing Algorithm
For more information, see Multiple Myeloma: Laboratory Screening
Specimen Type
SerumSpecimen 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 |
Special Instructions
Reference Values
1.21-2.70 mcg/mL
CPT Code Information
82232
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| B2M | Beta-2-Microglobulin, S | 1952-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| B2M | Beta-2-Microglobulin, S | 1952-1 |
Clinical Information
Beta-2-microglobulin (beta-2-M) is a small membrane protein (11,800 Da) associated with the heavy chains of class I major histocompatibility complex proteins and is, therefore, on the surface of all nucleated cells. The small size allows beta-2-M to pass through the glomerular membrane, but it is almost completely reabsorbed in the proximal tubules.
Serum beta-2-M levels are elevated in diseases associated with increased cell turnover. Levels are also elevated in several benign conditions such as chronic inflammation, liver disease, kidney dysfunction, some acute viral infections, and a number of malignancies, especially hematologic malignancies associated with the B-lymphocyte lineage.
In multiple myeloma, beta-2-M is a powerful prognostic factor, and values less than4 mcg/mL are considered a good prognostic factor.
In renal tubular disease, serum levels are low and urine levels are high. Although urine beta-2-M has been used to assess tubular dysfunction, it is not stable in urine below pH 5.5.
For more information see Multiple Myeloma: Laboratory Screening
Interpretation
A serum beta-2-microglobulin (beta-2-M) value of less than 4 mcg/mL is a good prognostic factor in patients with multiple myeloma. In a study of pretreatment serum beta-2-M levels in 100 patients with myeloma, it was reported that the median survival of patients with values greater than 4 mcg/mL was 12 months, whereas median survival for patients with values less than 4 mcg/mL was 43 months.
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
Nephelometry
Forms
If not ordering electronically, complete, print, and send Renal Diagnostics Test Request (T830)