TRUE-MOGAD Score: A Novel Scoring System to Identify MOGAD Among Positive MOG-IgG Test Results.

OBJECTIVES

Myelin oligodendrocyte glycoprotein (MOG) antibodies (MOG-IgG) are a biomarker of MOG antibody-associated disease (MOGAD). However, false positives remain common. We aimed to develop a scoring tool to guide interpretation.

METHODS

Observational study of MOG-IgG-positive patients at Mayo Clinic (May 2022-December 2024). The primary outcome was fulfillment of 2023-MOGAD diagnostic criteria. Predictive variables were identified using logistic regression, and scoring systems were derived and evaluated using receiver operating characteristic analysis. Internal (n = 92) and external (Johns Hopkins, n = 117) validation was performed.

RESULTS

Of 215 MOG-IgG positive patients, 144 were true positive per 2023-MOGAD diagnostic criteria (positive predictive value, 67.0%). The TRUE-MOGAD score included: Titers (MOG-IgG clear positive [+1 point]), Relapsing optic neuritis (≥3 [+1 point]), Under 18 years at onset [+1 point], Encephalitis phenotype (ADEM or cerebral cortical encephalitis at onset [+2 points]), MRI or other supportive features from 2023-MOGAD-criteria [+2 points], Oligoclonal bands in CSF [-2 points], Gradually progressive or Abrupt onset [-2 points], and Disappearance ≥1 T2-lesion [+1 point]. The score showed an area under the curve (AUC) of 0.983 (95%CI 0.961-1.000). The score was validated internally (AUC = 0.976) and externally (AUC = 0.977).

DISCUSSION: The TRUE-MOGAD score is a practical tool that accurately identifies MOGAD among positive MOG-IgG test results and may guide diagnostic and therapeutic decisions in clinical practice.

CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that a TRUE-MOGAD score of 2 or more accurately predicts MOGAD in patients with MOG-IgG titers of 1:20 or higher using the assay described.