The influence of smoking on the pattern of disability and relapse risk in AQP4-positive Neuromyelitis Optica Spectrum Disorder, MOG-Ab Disease and Multiple Sclerosis.

BACKGROUND: the role of smoking on clinical outcomes of central nervous system (CNS) inflammatory disorders is unclear. To assess the effect of smoking on relapses and disability in neuromyelitis optica with aquaporin-4-antibodies (NMOSD-AQP4-Ab), Myelin Oligodendrocyte Glycoprotein-antibodies associated disease (MOGAD) and relapsing remitting Multiple Sclerosis (MS) patients. METHODS: in a UK cohort of 101 NMOSD-AQP4-Ab, 70 MOGAD and 159 MS, and a Korean cohort of 97 NMOSD-AQ4-Ab, time to first relapse, annualised relapse rate, onset relapse severity and recovery, time to Expanded Disability Status Score(EDSS)/secondary progressive MS (SPMS) were compared between never-smokers and ever-smokers. All clinical data were collected under the local ethics between January 2017 and January 2019. RESULTS: Smoking did not affect the risk of relapse in any of the diseases. The risk of reaching EDSS 6.0 in the UK NMOSD-AQP4-Ab cohort was higher in ever smokers but this did not achieve significance (HR 2.12, p=0.068). When combining the UK and Korea NMOSD-AQP4-Ab cohorts, poorer recovery from the onset attack was significantly more frequent in the ever-smokers versus the never smokers (55% vs 38%, p=0.04). In the MS cohort the risk of reaching EDSS 6 and SPMS was significantly higher in the ever-smokers (HR=2.67, p=0.01 and HR=3.18, p=0.001). In MOGAD similar patterns were seen without reaching significance. CONCLUSIONS: In NMOSD-AQP4-Ab smoking associates with worse disability not through an increased risk of relapses but through poor relapse recovery. As in MS, smoking cessation should be encouraged in NMOSD-AQP4-Ab.

Cohort profile: a collaborative multicentre study of retinal optical coherence tomography in 539 patients with neuromyelitis optica spectrum disorders (CROCTINO).

PURPOSE: Optical coherence tomography (OCT) captures retinal damage in neuromyelitis optica spectrum disorders (NMOSD). Previous studies investigating OCT in NMOSD have been limited by the rareness and heterogeneity of the disease. The goal of this study was to establish an image repository platform, which will facilitate neuroimaging studies in NMOSD. Here we summarise the profile of the Collaborative OCT in NMOSD repository as the initial effort in establishing this platform. This repository should prove invaluable for studies using OCT to investigate NMOSD. PARTICIPANTS: The current cohort includes data from 539 patients with NMOSD and 114 healthy controls. These were collected at 22 participating centres from North and South America, Asia and Europe. The dataset consists of demographic details, diagnosis, antibody status, clinical disability, visual function, history of optic neuritis and other NMOSD defining attacks, and OCT source data from three different OCT devices. FINDINGS TO DATE: The cohort informs similar demographic and clinical characteristics as those of previously published NMOSD cohorts. The image repository platform and centre network continue to be available for future prospective neuroimaging studies in NMOSD. For the conduct of the study, we have refined OCT image quality criteria and developed a cross-device intraretinal segmentation pipeline. FUTURE PLANS: We are pursuing several scientific projects based on the repository, such as analysing retinal layer thickness measurements, in this cohort in an attempt to identify differences between distinct disease phenotypes, demographics and ethnicities. The dataset will be available for further projects to interested, qualified parties, such as those using specialised image analysis or artificial intelligence applications.