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Test Code B2MC Beta-2-Microglobulin (Beta-2-M), Spinal Fluid

Reporting Name

Beta-2-Microglobulin, CSF

Useful For

Evaluation of central nervous system inflammation and B-cell proliferative diseases

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required

Container/Tube: Sterile vial

Specimen Volume: 1 mL

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
CSF Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reference Values

0.70-1.80 mcg/mL

Day(s) and Time(s) Performed

Monday through Saturday; 3 p.m.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
B2MC Beta-2-Microglobulin, CSF 1951-3


Result ID Test Result Name Result LOINC Value
B2MC Beta-2-Microglobulin, CSF 1951-3

Clinical Information

Beta-2-microglobulin (BETA-2-M) is a small membrane protein (11,800 Dalton) 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.


Increased BETA-2-M levels in the cerebrospinal fluid (CSF) have been shown to be of diagnostic use in non-Hodgkin lymphoma with central nervous system involvement. Elevated CSF:serum ratios seen in patients with aseptic meningo-encephalitis suggest the possibility of neurologic processes including those associated with HIV infection and acute lymphoblastic leukemia. BETA-2-M measurement in multiple sclerosis seems to be of indeterminate usefulness.


Elevations of cerebrospinal fluid beta-2-microgobulin levels may be seen in a number of diseases including malignancies, autoimmune disease, and neurological disorders.

Clinical Reference

1. Koch T, Lichtenfeld K, Wiernik P: Detection of central nervous system metastasis with cerebrospinal fluid beta 2 microglobulin. Cancer 1983;52:101-104

2. Mavligit G, Stuckey S, Fernando B, et al: Diagnosis of leukemia or lymphoma in the central nervous system by beta 2 microglobulin determination. N Engl J Med 1980;303:718-722

3. Jeffrey G, Frampton C, Legge H, et al: Cerebrospinal fluid beta 2 microglobulin levels in meningeal involvement by malignancy. Pathology 1990;22:20-23

4. Us O, Lolli F, Baig S, Link H: Intrathecal synthesis of beta 2 microglobulin in multiple sclerosis and aseptic meningo-encephalitis. Acta Neurol Scand 1989;80(6):598-602

5. Elovaara I, Livanainen M, Poitainen E, et al: CSF and serum beta 2 microglobulin in HIV infection related to neurological dysfunction. Acta Neurol Scand 1989;79(2):81-87

6. Dolan MF, Lucey DR, Hendrix CW, et al: Early markers of HIV infection and subclinical disease progression. Vaccine 1993;11(5):548-551

7. Brew BJ, Bhalla RB, Fleisher M, et al: Cerebrospinal fluid beta 2 microglobulin in patients infected with human immunodeficiency virus. Neurology 1989;39(6):830-834

8. Musto P, Tomasi P, Cascavilla N, et al: Significance and limits of cerebrospinal fluid beta 2 microglobulin measurement in course of acute lymphoblastic leukemia. Am J Hematol 1988;28(4):213-218

9. Lucey DR, McGuire SA, Clerici M, et al: Comparison of spinal fluid beta 2-microglobulin levels with CD4 + T cell count, in vitro T helper cell function, and spinal fluid IgG parameters in 163 neurologically normal adults infected with the human immunodeficiency virus type l. J Infect Dis 1991;163:971

10. Bjerrum L, Bach F, Zeeberg I: Increased level of cerebrospinal fluid beta 2 microglobulin is related to neurologic impairment in multiple sclerosis. Acta Neurol Scand 1988;78:72-75

Analytic Time

Same day/1 day

Reject Due To


Mild OK; Gross OK







Method Name