New Review Identifies Key Biomarkers for Diagnosing and Tracking ADEM and MOG Antibody Disease
Acute disseminated encephalomyelitis, or ADEM, is a condition in which the immune system suddenly attacks the brain and spinal cord, triggering widespread inflammation that strips away the protective myelin coating on nerve fibers. It typically strikes children, often emerging in the days or weeks after a viral infection. The onset can feel sudden and terrifying: a child may develop high fever, confusion, difficulty walking or speaking, vision problems, or seizures within a short window. For families, the experience is often disorienting, in part because ADEM is rare, frequently misunderstood, and can look like several other serious neurological conditions on brain imaging.
In recent years, researchers have identified an important connection between ADEM and a distinct immune-mediated disorder called myelin oligodendrocyte glycoprotein antibody-associated disease, or MOGAD. This condition is defined by the presence of antibodies that target MOG, a protein found on the outermost surface of the myelin-producing cells in the brain and spinal cord. In children, ADEM is the most common way MOGAD presents. Other manifestations of MOGAD include optic neuritis, inflammation of the optic nerve that can cause sudden vision loss, and transverse myelitis, inflammation of the spinal cord. Recognizing whether a case of ADEM is part of the MOGAD spectrum has real consequences, because it changes the likelihood of relapse and informs treatment decisions.
A review published in June 2025 in Frontiers in Immunology, led by Tamang Sapana and Zhihong Zhuo at Zhengzhou University in China, compiled the current evidence on biomarkers in MOGAD, with direct relevance for patients with ADEM. Biomarkers are measurable biological signals, drawn from blood, spinal fluid, or imaging, that tell clinicians something about what is happening inside the nervous system even when symptoms alone are unclear. The review organized biomarkers into categories: those used for diagnosis, those that predict prognosis and relapse risk, those that track disease during treatment, and emerging experimental markers.
The most critical diagnostic biomarker is the MOG-IgG antibody itself, detected using a live cell-based assay. This testing method shows high sensitivity and specificity, meaning it reliably identifies MOGAD while rarely returning false positives. Approximately half of all children presenting with ADEM will test positive for MOG-IgG, a finding that changes the clinical picture significantly. Children who test positive are at higher risk of a relapsing disease course, particularly if their MOG-IgG titers remain persistently elevated over time. Tracking MOG-IgG titer trends, rather than a single test result, appears to offer more meaningful information about relapse risk.
Beyond MOG-IgG, the review highlights serum neurofilament light chain (sNfL) and serum GFAP (glial fibrillary acidic protein) as promising prognostic tools. Neurofilament light chain is a structural protein released into the bloodstream when nerve axons are damaged; elevated levels signal active neurological injury. GFAP is released when star-shaped support cells in the brain called astrocytes are stressed or damaged. Both of these blood-based biomarkers can reflect disease severity and predict relapse risk, offering a way to monitor the nervous system between MRI scans or clinical appointments.
One sobering point from this review is that unlike multiple sclerosis and neuromyelitis optica spectrum disorder, MOGAD still has no approved disease-modifying therapies. High-dose intravenous corticosteroids and IVIG are the mainstays of acute treatment, and for children with recurring episodes, long-term IVIG or rituximab is sometimes prescribed. The growing biomarker evidence base is helping clinicians make smarter decisions about who needs more aggressive maintenance therapy. For families managing ADEM or MOGAD, understanding these diagnostic and monitoring tools can be an important part of advocating for thorough evaluation and follow-up care.
Source: Frontiers in Immunology / PubMed Central (PMC12178866), June 6, 2025. Sapana T, Zhuo Z. DOI: 10.3389/fimmu.2025.1594960. This summary is for informational purposes only and does not constitute medical advice. Please consult a qualified healthcare provider for guidance specific to your situation.