CSF myelin basic protein is a test to measure the level of myelin basic protein (MBP) in the cerebrospinal fluid (CSF).
CSF is a clear liquid that surrounds the brain and spinal cord.
MBP is found in the material that covers many of your nerves.
A sample of spinal fluid is needed. This is done using a lumbar puncture.
This test is done to see if myelin is breaking down. Multiple sclerosis is the most common cause for this, but other causes may include:
In general, there should be less than 4 ng/mL of myelin basic protein in the CSF.
Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.
The example above shows the common measurement result for this test. Some laboratories use different measurements or may test different specimens.
What Abnormal Results Mean
Myelin basic protein levels between 4 and 8 ng/mL may be a sign of a long-term (chronic) breakdown of myelin. It may also indicate recovery from an acute episode of myelin breakdown.
If the myelin basic protein level is greater than 9 ng/mL, myelin is actively breaking down.
Fabian MT, Krieger SC, Lublin FD. Multiple sclerosis and other inflammatory demyelinating diseases of the central nervous system. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier; 2016:chap 80.
Karcher DS, McPherson RA. Cerebrospinal, synovial, serous body fluids, and alternative specimens. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 29.