Devic's Disease

New Antibody Marker Aids in Diagnosis of Neuromyelitis Optica

A team of Mayo Clinic scientists led by Dr. Vanda Lennon recently reported the discovery of a protein targeted by an antibody that distinguishes neuromyelitis optica (NMO, also known as Devic's disease) from more common forms of multiple sclerosis (MS) that are generally less severe. (See publications below.) The antibody is proving to be a valuable blood test for establishing the diagnosis of NMO and related diseases in the early symptom stage. This distinction is important because optimal treatments differ for NMO and MS.

The test, NMO-IgG, is available through Mayo Medical Laboratories.

Frequently Asked Questions about NMO-IgG

What type of sample is required for the test?
Four mL of serum, sent cool or frozen, is all that is required. The test may also be done on spinal fluid, but accompanying serum should always be sent.

Is the test positive in all cases of NMO?
No. Presently, it is detectable in approximately 70 percent of cases. Therefore a negative result does not rule out a diagnosis of NMO.

Is the test positive in ordinary MS?
No. Based on current research, it is able to reliably distinguish attacks of myelitis and optic neuritis due to MS from those due to NMO.

For which patients is the test most helpful?
It appears to be helpful in cases of severe or recurrent optic neuritis and in cases with severe or recurrent transverse myelitis, especially when a spinal cord lesion on MRI extends over three or more vertebral segments.

Should the test be done only once?
In many patients with NMO the test is positive from the first symptom. However, occasionally the test will convert from negative to positive, and retesting in a year may be appropriate in cases where there is a high index of suspicion for this diagnosis. Whether the titer of the antibody correlates with the activity or severity of the condition is unknown at the present time.

Mayo Clinic Publications Related to New Antibody Marker

Vanda A. Lennon, Thomas J. Kryzer, Sean J. Pittock, A.S. Verkman, and Shannon R. Hinson. IgG marker of optic-spinal multiple sclerosis binds to the aquaporin-4 water channel. Journal of Experimental Medicine. August 8, 2005. [Abstract]

Lennon VA, Wingerchuk DM, Kryzer TJ, Pittock SJ, Lucchinetti CF, Fujihara K, Nakashima I, Weinshenker BG. A serum autoantibody marker of neuromyelitis optica: distinction from multiple sclerosis. Lancet. 2004 Dec 11;364(9451):2106-12. [Abstract]