Age and Initial Attack Type Shape Patterns of Attack Type Recurrence in Relapsing MOGAD
Mulan Jiang1, Matthew Rode2, Dayoung Seo3, Alvin Song4, Maryam Alkanderi4, Ilinca Dumitru4, Anastasia Vishnevetsky5, Takahisa Mikami5, Monique Anderson5, Rebecca Gillani5, Rebecca Salky5, Gabriela Romanow5, Mattia Wruble5, Yoji Hoshina6, Susan Recio5, Fabian Murillo7, John Chen2, Sean Pittock2, Adil Harroud4, Michael Levy5, Eun-Jae Lee3, Eoin Flanagan2, Philippe-Antoine Bilodeau5
1Harvard Medical School, 2Mayo Clinic, 3Asan Medical Center, 4McGill University, 5Massachusetts General Hospital, 6University of Utah Health, 7Brigham and Women's Hospital
Objective:

To characterize attack type recurrence in relapsing myelin oligodendrocyte glycoprotein antibody disease (MOGAD)

Background:

Core MOGAD attack types include optic neuritis (ON), transverse myelitis (TM), and brain involvement. While population-level attack type frequencies vary with age, it remains unclear whether patients show tropism for recurrence of their initial attack type.

Design/Methods:

A retrospective cohort study was conducted of MOGAD patients meeting 2023 diagnostic criteria seen at Mass General Brigham and Mayo Clinic. Generalized additive models (GAMs) were fitted to first attacks to quantify age-expected attack type probabilities, and conditional GAMs were fitted separately for each initial attack type subgroup using subsequent attacks; deviations between the two were computed to isolate the effect of initial attack type. Permutation tests (1,000 iterations) compared observed attack type recurrence rates within four age-at-onset subgroups (0-12, 12-18, 18-40, 40+ years) against a null distribution drawn from a corresponding age-stratified pool of first attacks to assess whether age at onset affects tropism. Bonferroni correction was applied for multiple comparisons.

Results:

Of 493 patients meeting criteria, 359 had relapsing disease, contributing 1,245 attacks (median follow-up: 7.1 years; interquartile range: 3.4-12.3). Relapses involving new regions occurred in 145 patients (40.4%), who had a younger median age at onset (27 vs. 34 years, p<0.001) and more likely initially presented with TM or brain (p<0.001). Patients demonstrated tropism for recurrence of their initial attack type beyond age-matched reference probabilities. Tropism strengthened with older age at onset: ON tropism was significant in all age groups (risk ratios: 1.14-1.29), TM tropism emerged after 40 (RR: 1.96 [1.27-4.06]), and brain tropism emerged after 18 (RRs: 2.91-3.31).

Conclusions:

Attack type recurrence is shaped by both age and initial attack locations. Tropism strengthens with age, persisting even after accounting for age-dependent shifts in prevalence. These findings can inform prognostication, clinical trial design, and studies of pathophysiology.

Generative AI Usage
Yes, used generative AI in the drafting or editing in this abstract.

Tool, version, and prompt(s) used, as well as area of the abstract affected
The authors used Anthropic as the provider for Positron Assistant, which was used for coding assistance in the data analysis. The code was then independently verified. Claude (Sonnet 4.6) was also used for writing assistance in reducing abstract length and rephrasing sentences for clarity (representative prompt: "Point out 4 words to cut").
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.