BETA-2-MICROGLOBULIN, URINE
- Code
- 000.0000
- Name
- BETA-2-MICROGLOBULIN, URINE
- Category
- None
- Department
- Send-Out
- Start Date
- Expiration Date
- Synonyms
- CPT Codes
- 82232
- Site
- SBMF
- Reference Test
- 30007
Specimen Information
- Type
Urine, random
- Volume
1.0 ml
- Transport Info
Refrigerated 48 Hours
- Fasting Required?
- False
- Patient Instructions
Once collected, adjust the pH of the urine to between 6 and 8 with 1.0 M NaOH.
- Reference Range
Less than or equal to 300 µg/L
- Methodology
Chemiluminescence Immunoassay (CLIA)
Clinical Significance
Evaluate renal disease, activity of chronic lymphocytic leukemia, AIDS activity.
Beta-2 Microglobulin (B2M) comprises the light chain of the major histocompatibility antigen and is found on the surface of most nucleated cells. It is found in both serum and urine of normal individuals. B2M readily passes through the glomerular membrane and is reabsorbed and degraded in the proximal tube. Proximal tubular dysfunction results in elevated concentrations of urinary B2M, thereby providing a means of distinguishing proximal tubular from glomerular renal diseases.Serum levels of B2M are a function of its rate of synthesis or release into the serum pool and its rate of clearance. In inflammatory disorders (e.g., rheumatoid arthritis, systemic lupus erythematosus, Sjögren’s Syndrome and Crohn’s disease) and in lymphoproliferative diseases (e.g., multiple myeloma, b cell lymphoma and chronic lymphocytic leukemia), serum B2M levels are frequently elevated reflecting an increased rate of synthesis. Serum levels are also elevated because of decreased rates of clearance of this protein due to renal insufficiency as described above.