2026 American Academy of Neurology Autoimmune Abstract Website

Objective:

To synthesize available evidence on MOGAD in Iran and quantify the gap between AQP4-IgG seropositivity observed in Iranian NMOSD cohorts and international benchmarks, with implications for an under-recognized MOGAD burden.

Background:

The 2023 International MOGAD Panel criteria established MOGAD as distinct from multiple sclerosis (MS) and AQP4-IgG+ NMOSD. Although Iran maintains established MS and NMOSD registries (NMSRI, IMSS, NMORI), no dedicated MOGAD epidemiologic study has been published to date.

Design/Methods:

Narrative of Iranian NMOSD cohorts reporting AQP4-IgG seroprevalence, and 2024–2026 international MOGAD evidence indexed in PubMed, Scopus, and Web of Science through early 2026.

Results:

Global MOGAD prevalence is 1.3–2.5/100,000, with annual incidence of 3.4–4.8/million, a bimodal age distribution, and no clear sex, racial, or latitude predilection. Phenotypes include optic neuritis, ADEM, myelitis, brainstem syndromes, and cortical encephalitis, with relapsing disease in 40–80% and worse outcomes in adults. Iranian NMOSD cohorts report AQP4-IgG seropositivity of 46.8% (Tehran), 54.2% (Khuzestan), and ~52.5%, substantially below the 73–90% reported in Western series — strongly suggesting an under-recognized MOGAD population among AQP4-negative cases. Diagnosis requires serum MOG-IgG on cell-based assays (CBA) in compatible clinical/radiologic syndromes while excluding MS; fixed CBAs show high agreement with live assays (κ≈0.98), enabling diagnosis in resource-limited settings. Distinguishing MRI features include perineural optic nerve enhancement, spinal cord "H-sign," lesion resolution over time, and low brain lesion burden. Treatment differs fundamentally from MS, whose disease-modifying therapies are ineffective or potentially harmful. Acute attacks respond to steroids, with plasma exchange for refractory cases; for relapse prevention, IVIG and oral corticosteroids show the most consistent benefit, while rituximab remains an alternatives.

Conclusions:

MOGAD is likely underdiagnosed in Iran. Establishing a dedicated MOGAD module within existing registries, re-examining stored AQP4-negative NMOSD/ADS sera with cell-based MOG-IgG assays, and including Iranian centers in international MOGAD registries are essential steps to define the national MOGAD burden and guide targeted management.