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HelpTest Code SOFT: Z1000 Beta-2-Microglobulin (Beta-2-M), Spinal Fluid
Additional Codes
| Ordering Mnemonic | Mayo Test ID |
|---|---|
| HOM: MISC LAB | B2MC |
Reporting Name
Beta-2-Microglobulin, CSFUseful For
Evaluation of central nervous system inflammation and B-cell proliferative diseases
Method Name
Nephelometry
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
CSFSpecimen Required
Container/Tube: Sterile vial
Specimen Volume: 1 mL
Collection Instructions: Send spinal fluid from collection vial 1.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| CSF | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 14 days |
Reject Due To
| Gross hemolysis | OK |
Reference Values
0.70-1.80 mcg/mL
Day(s) Performed
Monday through Friday
CPT Code Information
82232
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 |
Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.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.
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 meningoencephalitis 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.
Interpretation
Elevations of cerebrospinal fluid beta-2-microgobulin levels may be seen in a number of diseases including malignancies, autoimmune disease, and neurological disorders.
Cautions
Results determined by assays using different manufacturers or methods may not be comparable.
Clinical Reference
1. Koch TR, Lichtenfeld KM, Wiernik PH: Detection of central nervous system metastasis with cerebrospinal fluid beta-2-microglobulin. Cancer. 1983 Jul;52(1):101-104
2. Mavligit GM, Stuckey SE, Cabanillas FF, et al: Diagnosis of leukemia or lymphoma in the central nervous system by beta-2-microglobulin determination. N Engl J Med. 1980 Sep 25;303(13):718-722
3. Jeffery GM, Frampton CM, Legge HM, Hart DN: Cerebrospinal fluid beta 2-microglobulin levels in meningeal involvement by malignancy. Pathology. 1990 Jan;22(1):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 Dec;80(6):598-602
5. Elovaara I, Livanainen M, Poutianen E, et al: CSF and serum beta-2-microglobulin in HIV infection related to neurological dysfunction. Acta Neurol Scand. 1989 Feb;79(2):81-87
6. Dolan MJ, Lucey DR, Hendrix CW, Melcher GP, Spencer GA, Boswell RN: 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 Jun;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 Aug;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 May;163(5):971-975
10. Bjerrum OW, Bach FW, Zeeberg I: Increased level of cerebrospinal fluid beta 2-microglobulin is related to neurologic impairment in multiple sclerosis. Acta Neurol Scand. 1988 Jul;78(1):72-75
11. Dietzen DJ, Willrich MAV: Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham CAD, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 31
Method Description
In this Siemens Nephelometer II method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume. A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light emitting diode, which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement. The result is calculated by subtracting the value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Instruction manual: Siemens Nephelometer II, Siemens, Inc.; Version 3, 2008; Addendum to the Instruction Manual 2.3, 08/2017)