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Beta-2 Microglobulin Kidney Disease

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Also known as: B2M; B2M; β2-Microglobulin; Thymotaxin
Formal name: Beta2 Microglobulin, Serum or Urine

Were you looking for Beta-2 Microglobulin Tumor Marker, ordered to detect and monitor certain blood cell cancers?

At a Glance

Why Get Tested?

To help detect kidney damage and follow kidney disorders; sometimes to monitor people who are exposed to cadmium

When to Get Tested?

When you have symptoms and signs associated with kidney dysfunction; periodically if you work with cadmium

Sample Required?

A blood sample drawn from a vein in your arm; sometimes a random or 24-hour urine sample

Test Preparation Needed?

None

The Test Sample

What is being tested?

Beta-2 microglobulin (B2M) is a protein that is found on the surface of nucleated cells (contain a nucleus) and functions as part of the human immune system. This protein is routinely shed by cells into the blood and is present in most body fluids, with highest levels in the blood, generally lower levels in spinal fluid, and trace levels in urine.

Drawing of a kidney and the urinary tract

In the kidneys, B2M passes through blood-filtering units called the glomeruli and is then reabsorbed by the renal proximal tubules, structures that reclaim water, proteins, vitamins, minerals, and other vital substances. Normally, only small amounts of B2M are present in the urine, but when the renal tubules become damaged or diseased, B2M concentrations increase due to the decreased ability to reabsorb this protein. When the glomeruli in the kidneys are damaged, they are unable to filter out B2M, so the level in the blood rises.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm. A random or 24-hour urine sample may also be collected.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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Article Sources

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

Sources Used in Current Review

Basu, A. et. al. (Updated 2012 August 2). Dialysis-Related Beta-2m Amyloidosis. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/246542-overview through http://emedicine.medscape.com. Accessed June 2013.

Gooptu, M. and Scarpaci, A. (Updated 2012 April 6). Beta2-Microglobulin. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/2086864-overview through http://emedicine.medscape.com. Accessed June 2013.

Beta-2-Microglobulin (Beta-2-M), Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/9234 through http://www.mayomedicallaboratories.com. Accessed June 2013.

Liabeuf, S. (2012 August 15). Plasma beta-2 microglobulin is associated with cardiovascular disease in uremic patients. Kidney International (2012) 82, 1297–1303 Abstract [On-line information]. Available online at http://www.nature.com/ki/journal/v82/n12/abs/ki2012301a.html through http://www.nature.com. Accessed June 2013.

(Updated 2010 September 9). Amyloidosis and Kidney Disease. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) [On-line information]. Available online at http://kidney.niddk.nih.gov/kudiseases/pubs/amyloidosis/ through http://kidney.niddk.nih.gov. Accessed June 2013.

Winchester, J. (2005 July). Novel Changes in Beta2-Microglobulin in Dialysis Patients. Clinical Chemistry v 51 (7) 1089-1090 [On-line information]. Available online at http://www.clinchem.org/content/51/7/1089.full through http://www.clinchem.org. Accessed June 2013.

Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 680-682.

Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER, Bruns DE, eds. 4th edition, St. Louis: Elsevier Saunders; 2006, pg 555.

Rao LV, Pechet L, Jenkins A, et al. Laboratory tests, in Wallach's Interpretation of Diagnostic Tests, 9th ed. (2011) Williamson MA, Snyder ML, eds. Lippincott Williams & Wilkins. Chapter 2.

Sources Used in Previous Reviews

Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 155-156.

Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 742-743.

Basu, A. et. al. (Updated 2008 February 22). Amyloidosis, Beta2M (Dialysis-Related) eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/246542-overview through http://emedicine.medscape.com. Accessed August 2009.

Holmes, R. et. al. (Updated: 2009 July 30). Amyloidosis, Overview. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/335414-overview through http://emedicine.medscape.com. Accessed August 2009.

(Updated 2008 September). Renal Function Markers - Kidney Disease. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/RenalDz/RenalFunctionMarkers.html?client_ID=LTD through http://www.arupconsult.com. Accessed August 2009.

(© 1995–2009). Overview: Beta-2 Microglobulin (B[2]-M), Urine. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/300243 through http://www.mayomedicallaboratories.com. Accessed August 2009.

(© 1995–2009). Overview: Beta-2-Microglobulin (Beta-2-M), Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/9234 through http://www.mayomedicallaboratories.com. Accessed August 2009.

(2006 May). Amyloidosis and Kidney Disease. National Kidney and Urologic Diseases Information Clearinghouse [On-line information]. Available online at http://kidney.niddk.nih.gov/kudiseases/pubs/amyloidosis/ through http://kidney.niddk.nih.gov. Accessed August 2009.

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