Biomarkers in patients with autoimmune optic neuritis not associated with multiple sclerosis: Demographic, clinical and prognostic features.

Background: The new optic neuritis (ON) classification leads to a change in how ON patients are grouped. Our aim is to appraise the clinical features and prognoses of patients with autoimmune ON not associated with MS.

Methods: Patients referred to our neuro-ophthalmology laboratory were enrolled to this retrospective study. Patients with ON associated with MS were excluded. The remaining patients were divided into three groups: aqauaporin-4 (AQP4) antibody ON group, myelin oligodendrocyte glycoprotein (MOG) antibody ON group, and seronegative ON group. The patients were examined on admission, one month after acute treatment, and at the third-year follow-up. We compared demographic, clinical, radiologic, laboratory data, and treatment responses among these three groups.

Results: The study included 92 patients. The older age of onset, bilateral simultaneous involvement of the optic nerves, severe vision loss at onset, and need for aggressive treatment were more common in the AQP-ON and the MOG-ON groups than the seronegative ON group (P = 0.01, P = 0.003, P = 0.011, P = 0.007, P < 0.001, P < 0.001, respectively). The presence of optic disc edema was a significant feature of MOG-ON as well as long-length contrast enhancement on MRI (P = 0.003, P = 0.002). Additional autoimmune antibodies and CNS lesions outside the optic nerve were the features of AQP4-ON patients (P < 0.001, P = 0.015). Generalized estimating equations analysis revealed that the presence of AQP4 antibody, increased age and recurrence were associated with visual acuity over time (P = 0.014, P = 0.002, P = 0.016, respectively).

Conclusion: The association of serum biomarker status with demographic, clinical features, and visual outcomes indicate the importance of biomarker detection in these patients.