MOG antibody-associated disease, or MOGAD, is emerging from the margins of neuroimmunology as clinicians gain a more precise framework for distinguishing it from multiple sclerosis, neuromyelitis optica spectrum disorder and other inflammatory diseases of the central nervous system. A systematic review and meta-analysis published in the Journal of Neurology has evaluated the diagnostic performance of the 2023 International MOGAD Panel criteria, examining how reliably the criteria identify patients across different clinical settings. The study is particularly important because MOGAD has no single defining clinical presentation. It can appear as optic neuritis, acute disseminated encephalomyelitis, transverse myelitis, brainstem inflammation or a combination of these syndromes, often overlapping with better-known demyelinating disorders.
The condition is associated with antibodies directed against myelin oligodendrocyte glycoprotein, a protein located on the outer surface of oligodendrocytes and the myelin sheath. MOG-IgG testing is therefore central to diagnosis, but the presence of an antibody alone does not automatically establish that a patient has MOGAD. Low-positive results can occur in people with other neurological conditions, and test performance varies according to the laboratory method, the antibody threshold and the clinical population being tested. The 2023 criteria were developed to address this problem by combining a compatible demyelinating event with MOG-IgG detection and additional clinical or radiological features that strengthen the diagnosis.
The new analysis brought together evidence from studies that assessed the criteria in two broad types of patient population. The first consisted of broad diagnostic-evaluation cohorts, in which individuals were investigated for a range of inflammatory, infectious, vascular and degenerative neurological disorders. The second included MOG-IgG-positive enriched cohorts, which contained a much larger proportion of patients already suspected of having MOGAD or known to carry the antibody. Separating these groups is technically essential. Diagnostic accuracy can appear exceptionally high when a test is examined in a population enriched with classic cases, whereas performance may be more demanding and clinically relevant when the same criteria are applied to patients whose symptoms and test results are less clear.
Across the available evidence, the 2023 criteria demonstrated strong diagnostic performance, supporting their use as a practical international standard. Their principal strength was the ability to identify patients with a characteristic demyelinating syndrome while requiring laboratory and clinical evidence that the antibody finding was meaningful. The analysis also indicated that performance was not uniform across all settings. Results were generally more favorable in enriched cohorts, where the pre-test probability of MOGAD was high, while broad diagnostic cohorts exposed the greater difficulty of distinguishing genuine disease from incidental or nonspecific MOG-IgG positivity. This difference does not necessarily weaken the criteria; rather, it shows why diagnostic interpretation must include the clinical context in which testing is performed.
The distinction between sensitivity and specificity is central to understanding the findings. Sensitivity describes the proportion of true MOGAD cases correctly recognized by the criteria, while specificity measures how effectively the criteria exclude patients who do not have the disease. A highly sensitive system reduces the risk of missed diagnoses, which is important because untreated attacks can leave permanent visual, motor or cognitive impairment. High specificity is equally important because MOGAD is treated with immunotherapies that may expose patients to infection and other complications. Misclassification can also lead to inappropriate long-term treatment, particularly when MOGAD is confused with multiple sclerosis or neuromyelitis optica spectrum disorder, conditions that may require different therapeutic strategies.
The panel’s framework reflects the biological complexity of MOGAD. In patients with strongly positive serum results obtained through validated cell-based assays, a compatible clinical syndrome may provide substantial diagnostic support. In contrast, weak-positive results demand greater caution and a closer search for supportive features. These may include bilateral or markedly swollen optic neuritis, longitudinally extensive myelitis, an acute disseminated encephalomyelitis-like presentation, distinctive brain lesions or a pattern of recovery that is more typical of MOGAD than of competing diagnoses. The criteria also emphasize that MOG-IgG should be interpreted in serum rather than relying primarily on cerebrospinal fluid, because serum testing is generally more sensitive for detecting the relevant antibody response.
The meta-analysis highlights a persistent challenge in antibody-based neurology: the meaning of a laboratory result depends on the patient population and the assay used. Live cell-based assays are designed to present native MOG on the surface of cells, allowing antibodies to bind the protein in a configuration closer to that found in human tissue. However, different platforms, cut-off values and laboratory procedures can produce different results. The likelihood that a positive result represents true disease is also influenced by prevalence. In a specialist MOGAD clinic, a positive result may have a high positive predictive value; in a general neurology service testing many patients with atypical symptoms, the same result may be less decisive.
For clinicians, the findings reinforce a stepwise approach rather than an antibody-first diagnosis. Physicians must first determine whether the patient has a recognizable central nervous system demyelinating event. They must then evaluate the strength and reliability of the MOG-IgG result, review magnetic-resonance imaging and consider alternative diagnoses, including multiple sclerosis, aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder, infection, ischemia and malignancy. The criteria are therefore best understood as a structured diagnostic safeguard. They organize evidence and reduce inconsistency, but they do not replace expert judgment, especially in patients with low antibody titers, atypical symptoms or a clinical course that does not fit the usual spectrum of MOGAD.
The study also carries implications for future research and clinical trials. Reliable case definitions are necessary for comparing treatment outcomes, estimating relapse risk and determining whether a therapy prevents disability. If different research groups enroll patients using incompatible diagnostic standards, apparently conflicting findings may simply reflect differences in patient selection. By testing the 2023 criteria across broad and enriched cohorts, the review provides a clearer picture of where the framework performs well and where additional validation is needed. Future studies will likely focus on children, patients with isolated seizures or cognitive symptoms, individuals with borderline antibody results and populations from regions where access to specialized testing remains limited.
The overall message is one of confidence tempered by caution. The 2023 International MOGAD Panel criteria offer a robust and clinically useful method for diagnosing a disease that was frequently hidden within broader categories of inflammatory demyelination. Their high performance across evaluated cohorts supports wider adoption, while the differences between broad and antibody-enriched populations demonstrate why test results must never be interpreted in isolation. As MOGAD recognition expands, combining a compatible neurological syndrome, validated antibody testing, supportive imaging and rigorous exclusion of alternatives will remain the safest route to accurate diagnosis and timely treatment.
Subject of Research: Diagnostic performance of the 2023 International MOGAD Panel criteria for identifying myelin oligodendrocyte glycoprotein antibody-associated disease.
Article Title: Diagnostic performance of the 2023 International MOGAD Panel criteria in broad diagnostic-evaluation and MOG-IgG-positive enriched cohorts: a systematic review and meta-analysis
Article References: Journal of Neurology, Springer Nature, article associated with DOI 10.1007/s00415-026-14079-3.
Image Credits: AI Generated
DOI: 10.1007/s00415-026-14079-3
Keywords: MOGAD, MOG-IgG, myelin oligodendrocyte glycoprotein, autoimmune demyelination, optic neuritis, transverse myelitis, diagnostic criteria, systematic review, meta-analysis, neuroimmunology.
