Late onset neuromyelitis optica spectrum disorder with anti‐aquaporin 4 and anti‐myelin oligodendrocyte glycoprotein antibodies

BACKGROUND AND PURPOSE: This study aimed to evaluate the clinical characteristics and prognosis of late onset (≥50 years) neuromyelitis optica spectrum disorder (LO-NMOSD), and compare them with those of early onset (<50 years) NMOSD (EO-NMOSD) and NMOSD with various antibody serostatuses. METHODS: From January 2015 to December 2020, 360 anti-aquaporin 4 antibody (AQP4-ab)-positive and 130 anti-myelin oligodendrocyte glycoprotein antibody (MOG-ab)-positive patients presented to the Huashan Hospital, China. We retrospectively reviewed their medical records, including the Expanded Disability Status Scale (EDSS) score at each visit and the annualized relapse rate (ARR). Prognostic outcomes included the time to first relapse, blindness, motor dysfunction, severe motor dysfunction, and death. Correlations between the age at onset, lesion location, and clinical parameters were analyzed. RESULTS: This study included 122 (24.9%) patients with LO-NMOSD, 101 with AQP4-ab and 21 with MOG-ab. Compared with EO-NMOSD patients, those with LO-NMOSD had higher EDSS scores and more frequent disease onset with transverse myelitis, blindness, motor dysfunction, and severe motor dysfunction. Compared with LO-NMOSD patients with MOG-ab, those with AQP4-ab had a worse prognosis. Age at disease onset had a significantly positive correlation with EDSS score at the last follow-up of all NMOSD patients, but a negative correlation with ARR-1 (ARR excluding the first attack, calculated from disease onset to final follow-up) in NMOSD patients with AQP4-ab. CONCLUSIONS: Patients with LO-NMOSD, especially those with AQP4-ab, had a worse prognosis compared with patients with EO-NMOSD. Age at disease onset and antibody serostatus predicted blindness and motor dysfunction.