Blood Test Differentiates Devic Syndrome From MS

A joint research effort from Japan and the Mayo Clinic has identified an antibody that can help differentiate Devic syndrome-or neuromyelitis optica (NMO)-from multiple sclerosis (MS). NMO is generally considered to be a rare disease, but it may be underrecognized and is often misdiagnosed as MS, although it demands a treatment protocol that differs from that of MS. Indeed, in some countries, misdiagnosis may be as high as 30%, according to Mayo Clinic estimates. A research team hailing from the Department of Immunology and Neurology at the Mayo Clinic in Rochester, NY, led by neuroimmunologist Vanda A. Lennon, MD, PhD, in collaboration with a research team from Tohoku University School of Medicine in Japan, identified the autoantibody NMO-IgG, which appears to be a reliable marker for differentiating NMO from MS. "A major importance of the autoantibody is that its detection excludes the diagnosis of classical MS in its early stages when its differentiation from NMO is often difficult," explained Lennon. Seropositivity favors relapsing optical neuritis and continued degeneration-leading to loss of vision and paralysis-which underscores the importance of early identification and treatment with immunosuppressive therapies to minimize morbidity. "With this biomarker, physicians are in a much better position to start optimal therapies sooner, and hopefully lessen the impact of the disease," said Lennon. "Another important outcome of this research will be the reclassification of CNS demyelinating disorders in which NMO-IgG is detected," said Lennon. "This will aid epidemiological studies and more appropriate design of therapeutic trials." Further questions that Lennon and her team hope to answer as they go forward are how the blood test for NMO-IgG will be applied in the clinical setting and whether other early differentiating signs and symptoms of Devic syndrome can be identified. For further information, see Lennon VA, Wingerchuk DM, Kryzer TJ, et al. A serum autoantibody marker of neuromyelitis optica: distinction from multiple sclerosis. Lancet. 2004;364:1206-2112.