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Beta-2-Microglobulin, Random Urine with Creatinine
Test Code38994
CPT Codes
82232, 82570
Preferred Specimen
10 mL urine collected in a Quest Diagnostics Beta-2 Microglobulin Transport Tube (available through Client Supply) and
10 mL urine collected in a plastic urine container for creatinine
10 mL urine collected in a plastic urine container for creatinine
Patient Preparation
Patient should void bladder, then drink at least 500 mL of (approximately 17 oz) of water.
Minimum Volume
10 mL (Beta-2 Microglobulin Transport Tube) • 0.5 mL (Plastic urine container)
Other Acceptable Specimens
See Collection Instructions
Instructions
Beta-2 Microglobulin
1. Patient should void bladder, then drink at least 500 mL (approximately 17 oz) of water.
2. A urine sample should be collected within 1 hour.
3. Pour exactly 10 mL of random urine into a Quest Diagnostics Beta-2 Microglobulin Transport Tube (available through Client Supply).
4. Ship room temperature.
5. Alternatively, if the collection tubes are not available, pH of the specimen must be adjusted to between 6 and 8 using 1N NaOH prior to shipping.
Beta-2 Microglobulin in urine is unstable in acidic urine (less than pH 6). Exactly 10 mL of urine in the Quest Diagnostics Beta-2 Microglobulin Transport Tube is required to achieve the required pH of between 6 and 8. Any volume of urine above or below 10 mL will result in a pH that is outside the acceptable range.
Creatinine
1. Pour 10 mL of random unpreserved urine, collected in a plastic urine container into a plastic transport tube.
1. Patient should void bladder, then drink at least 500 mL (approximately 17 oz) of water.
2. A urine sample should be collected within 1 hour.
3. Pour exactly 10 mL of random urine into a Quest Diagnostics Beta-2 Microglobulin Transport Tube (available through Client Supply).
4. Ship room temperature.
5. Alternatively, if the collection tubes are not available, pH of the specimen must be adjusted to between 6 and 8 using 1N NaOH prior to shipping.
Beta-2 Microglobulin in urine is unstable in acidic urine (less than pH 6). Exactly 10 mL of urine in the Quest Diagnostics Beta-2 Microglobulin Transport Tube is required to achieve the required pH of between 6 and 8. Any volume of urine above or below 10 mL will result in a pH that is outside the acceptable range.
Creatinine
1. Pour 10 mL of random unpreserved urine, collected in a plastic urine container into a plastic transport tube.
Transport Temperature
Room temperature
Specimen Stability
Beta-2 urine
Room temperature: 5 days
Refrigerated: 15 days
Frozen: 30 days
Creatinine urine
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Room temperature: 5 days
Refrigerated: 15 days
Frozen: 30 days
Creatinine urine
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Specimens received in a non-Beta-2 Microglobulin transport tube with a pH less than 6 • Any volume other than 10 mL urine in the transport tube • Specimens received past stability • Any specimen with pH less than 6
Methodology
Immunoturbidimetric
Setup Schedule
Set up: Mon-Sat; Report available: 3 days
Clinical Significance
Beta-2 Microglobulin (B2M) is a low molecular weight protein that forms the light chain component of the histocompatibility antigen. It is synthesized by all nucleated cell types. It is an integral part of the class I MHC antigens and is present in all body fluids. B2M is filtered through the glomeruli of the kidney and is then reabsorbed and catabolized by the proximal tubular cells. In normal patients only trace amounts of B2M appear in the urine. Elevated urine B2M is seen in tubulo-interstitial disorders. Increased urine B2M is seen in cadmium exposure, diatrizoate, exercise, fever, nephrectomy, semen. There is evidence that monitoring B2M levels in HIV-infected individuals offers an independent predictor of progression to AIDS, leukemia and lymphoma.
