CSF myelin basic protein is a test to measure the level of myelin basic protein (MBP) in the cerebrospinal fluid (CSF). The CSF is the clear liquid that surrounds the brain and spinal cord.
MBP is found in the material that covers many of your nerves.
How the test is performed
A sample of spinal fluid is needed. This is done using a lumbar puncture.
Why the test is performed
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:
- Bleeding of the central nervous system
- Central nervous system trauma
- Certain brain diseases (encephalopathies)
- Infection of the central nervous system
In general there should be less than 4 ng/mL of myelin basic protein in the CSF.
Note: ng/mL = nanogram per milliliter
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. 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 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.
Houtchens MK, Lublin FD, Miller AE, et al. Multiple sclerosis and other inflammatory demyelinating diseases of the central nervous system. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley’s Neurology in Clinical Practice. 6th ed. Philadelphia, Pa: Saunders Elsevier; 2012:chap 54.
Greene, DN, Schmidt, RL, Wilson, AR, et al. Cerebrospinal Fluid Myelin Basic Protein Is Frequently Ordered but Has Little Value. Am J Clin Pathol. 2012:138:262-272