Abstract. Alterations of cellular bioenergetics are a common feature in most neurodegenerative disorders. However, there is a selective vulnerability of different brain regions, cell types, and even mitochondrial populations to these metabolic disturbances. Thus, the aim of our study was to establish and validate an in vivo metabolic imaging technique to screen for mitochondrial function on the subcellular level. Based on nicotinamide adenine dinucleotide (phosphate) fluorescence lifetime imaging microscopy [NAD(P)H FLIM], we performed a quantitative correlation to high-resolution respirometry. Thereby, we revealed mitochondrial matrix pH as a decisive factor in imaging NAD(P)H redox state. By combining both parameters, we illustrate a quantitative, high-resolution assessment of mitochondrial function in metabolically modified cells as well as in an amyloid precursor protein-overexpressing model of Alzheimer's disease. Our metabolic imaging technique provides the basis for dissecting mitochondrial deficits not only in a range of neurodegenerative diseases, shedding light onto bioenergetic failures of cells remaining in their metabolic microenvironment. © The Authors.Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Background: Optimal management of anti-CD20-treated patients with multiple sclerosis (pwMS) is an important clinical task during the current severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. Objectives: To characterize humoral and cellular immune responses to SARS-CoV-2 vaccinations/infections in a longitudinal cohort of anti-CD20 treated ( n = 175) and anti-CD20 therapy-naïve ( n = 41) pwMS. Methods: Anti-SARS-CoV-2 spike protein immunoglobulin G (IgG) and IgA, virus neutralizing capacity, IgG avidity and SARS-CoV-2-specific T cells were determined. Results: Following two SARS-CoV-2 vaccinations, not only SARS-CoV-2 spike protein IgG and IgA, but also neutralizing capacity and avidity of SARS-CoV-2 IgG were lower in anti-CD20-treated ( n = 51) than in anti-CD20 therapy-naïve pwMS ( n = 14) and in healthy controls (HC, n = 19). However, in all anti-CD20-treated pwMS vaccinated twice ( n = 26) or infected with SARS-CoV-2 ( n = 2), in whom SARS-CoV-2-specific T cells were measured, SARS-CoV-2-specific T cells were detectable, at levels similar to those of twice-vaccinated anti-CD20 therapy-naïve pwMS ( n = 7) and HC ( n = 19). SARS-CoV-2-S1 IgG levels ( r = 0.42, p = 0.002), antibody avidity ( r = 0.7, p < 0.001), and neutralizing capacity ( r = 0.44, p = 0.03) increased with time between anti-CD20 infusion and second vaccination. Based on detection of SARS-CoV-2 antibodies, SARS-CoV-2 infections occurred in 4 out of 175 (2.3%) anti-CD20-treated pwMS, all of whom recovered fully. Conclusions: These findings should inform treatment decisions and SARS-CoV-2 vaccination management in pwMS.

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.