Mayo Researchers Correlate Specific Antibody with Relapse of Neurological Disorder
For patients who have been diagnosed with acute disseminated encephalomyelitis (ADEM), Mayo researchers have found a direct correlation between a specific antibody, myelin oligodendrocyte glycoprotein—also known as MOG, and an increased risk of recurring attacks in these individuals.
Mayo Clinic neurologists Sean Pittock, M.D., and Sebastian Lopez, M.D., have found that when patients test positive for the MOG antibody, they have an increased possibility of another ADEM episode. The study was published in JAMA Neurology.
About Acute Disseminated Encephalomyelitis
“Acute disseminated encephalomyelitis—often called ADEM—is a rare neurological disorder where inflammation occurs, usually in the brain, spinal cord or sometimes the optic nerves,” says Dr. Pittock, Director of the Mayo Clinic Neuroimmunology Laboratory and the Marilyn A. Park and Moon S. Park, M.D., Director of the Center for Multiple Sclerosis and Autoimmune Neurology. “Oftentimes, ADEM occurs in patients after a viral or bacterial infection, and it tends to occur more often in children than in adults.”
ADEM attacks usually occur only once, and most patients recover when treated with immunotherapy. Dr. Pittock says that symptoms may include fever, headache, nausea, and an altered mental status. In severe cases, individuals experience seizures or comas. “If we can help patients know whether or not they are more susceptible to relapses, this is very important,” says Dr. Pittock. “ADEM attacks can lead to further brain damage, loss of vision, or even paralysis.”
In the Mayo Clinic study, the researchers evaluated for the presence of the MOG antibody and whether the persistence of the antibody was associated with an increased risk of relapses after ADEM.
“We found that 88 percent of these patients who continued to have detectable antibodies suffered at least one more episode of inflammation of their central nervous system,” says Dr. Lopez, lead author on the study.
About Myelin Oligodendrocyte Glycoprotein and the Test
Myelin oligodendrocyte glycoprotein is a newly recognized antibody found in patients who have inflammatory central nervous system (CNS) disorders such as optic neuritis(inflammation of the optic nerve), transverse myelitis (spinal cord inflammation), encephalitis (brain inflammation) or, in some cases, a combination of these. The Mayo study evaluated a large cohort of patients (children and adults) with an initial diagnosis of ADEM. The study also suggests new diagnostic criteria for patients with inflammatory CNS disorders and positive MOG antibodies.
“We found that patients, children, and adults, who become ‘seronegative,’ which means the antibody is no longer present in their blood, are very unlikely to have another episode of CNS inflammation or a new ADEM attack,” adds Dr. Lopez.
The MOG antibody test is available to Mayo Clinic patients and health care providers worldwide through Mayo Medical Laboratories, the global reference laboratory of Mayo Clinic.
Distinguishing MS from Other Neurological Disorders
“Multiple sclerosis, or MS, can also affect the optic nerve, spinal cord or brain, which can make it difficult to distinguish from other CNS disorders,” says Dr. Pittock. “Because of this, many patients who are considered ‘MOG-antibody positive’ can be misdiagnosed with MS if they are not tested for this biomarker, and that means that they could be receiving treatment that may not be effective.”
“Testing for the MOG antibody in patients who present with optic neuritis, transverse myelitis, or brain inflammation is helpful because these patients represent a different subgroup of patients with CNS inflammatory disorders,” adds Dr. Lopez. “And while they share some features with MS, they have different outcomes, different responses to drugs, and a risk of relapse. Establishing the correct diagnosis is crucial, and MOG antibody testing—along with the application of the diagnostic criteria—can help with both diagnosis and treatment.”