The effect of smoking on MRI lesion resolution in NMOSD-AQP4 and MOGAD

Background: The effect of smoking on the resolution of magnetic resonance imaging (MRI) lesions in patients with neuromyelitis optica spectrum disorders with aquaporin-4 positive antibody (NMOSD-AQP4) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has not been studied before. Objective: We aimed to determine the effect of smoking on lesion resolution in MRI and assess its correlation with clinical recovery after a relapse. Methods: We conducted a cohort study including NMOSD-AQP4 and MOGAD patients with acute and follow-up MRI scans. We collected demographic, clinical, imaging and smoking data. Logistic regression models were fitted to predict the effect of smoking on lesion resolution and to assess whether clinical recovery was associated with MRI lesion resolution. Results: A total of 105 patients were included (57 with NMOSD-AQP4 and 48 with MOGAD). Current and past smoking was associated with a higher risk of persistent lesions in NMOSD-AQP4 and MOGAD (risk ratio (RR) = 3.4, 95% confidence interval (CI) = 2.5–4.7, p < 0.001). Additionally, the presence of lesion resolution was associated with better clinical recovery (RR = 1.9, 95% CI = 1.7–2.2, p < 0.001). Conclusion: Smoking is associated with worse MRI lesion resolution in patients with NMOSD-AQP4 and MOGAD, and lesion resolution correlates with clinical recovery. Our findings suggest a detrimental effect of smoking in inflammatory central nervous system (CNS) diseases.