Predictors of overlapping autoimmune disease in Neuromyelitis Optica Spectrum disorder (NMOSD): A retrospective analysis in two inner-city hospitals.

Background: The coexistence of Neuromyelitis Optica spectrum disorder (NMOSD) with other autoimmune dis-eases (AD-NMOSD) presents worse clinical outcomes and healthcare costs than NMOSD alone (NMOSD-only). NMOSD and other autoimmune diseases also have a higher prevalence and morbidity in Black. We aim to compare clinical features and treatment responses in NMOSD patients with and without overlapping autoim-munity in a predominantly Black cohort. We further identify predictors associated with each clinical subtype. Methods: AD-NMOSD (n = 14) and NMOSD-only (n = 27) patients were identified retrospectively. Demographic, clinical, laboratory, imaging, and response to treatment data were examined. Results: Our cohort was predominately Black (82.9%). The prevalence of grouped-comorbidities, history of in-fections, sensory symptoms, Expanded Disability Status Scale (EDSS) before treatment, double-stranded DNA, antinuclear, ribonucleoprotein, and antiphospholipid antibodies, spinal-cord edema, white matter occipital le-sions, and the levels of C-reactive protein, urine protein/creatinine, white blood cell count in cerebrospinal fluid (CSF), were higher in AD-NMOSD patients (p < 0.05 and/or Cramer's V > 30, Cohen's d > 50), whereas the age of males, visual symptoms, serum albumin, platelet count, and optic nerve enhancement were lower. EDSS after treatment improved in both groups being more evident in NMOSD-only patients (p = 0.003, SE = 0.58 vs p = 0.075, SE = 0.51). Other variables had a close to moderate SE, and others did not differ between NMOSD subtypes. A higher frequency of grouped-comorbidities, lower serum albumin, and platelet count were inde-pendently associated with a higher risk for AD-NMOSD.