A study on patients with neuromyelitis optica spectrum disorder from Eastern India

Dynamics of AQP4 upon exposure to seropositive patient serum before and after Rituximab therapy in Neuromyelitis Optica: A cell-based study

Neuromyelitis Optica (NMO) is an autoimmune inflammatory disease that affects the optic nerves and spinal cord. The autoantibody is generated against the abundant water channel protein of the brain, Aquaporin 4 (AQP4). Of the two isoforms of AQP4, the shorter one (M23) often exists as a supramolecular assembly known as an orthogonal array of particles (OAPs). There have been debates about the fate of these AQP4 clusters upon binding to the antibody, the exact mechanism of its turnover, and the proteins associated with the process. Recently several clinical cases of NMO were reported delineating the effect of Rituximab (RTX) therapy. Extending these reports at the cell signaling level, we developed a glioma based cellular model that mimicked antibody binding and helped us track the subsequent events including a variation of AQP4 levels, alterations in cellular morphology, and the changes in downstream signaling cascades. Our results revealed the extent of perturbations in the signaling pathways related to stress involving ERK, JNK, and AKT1 together with markers for cell death. We could also decipher the possible routes of degradation of AQP4, post-exposure to antibody. We further investigated the effect of autoantibody on AQP4 transcriptional level and involvement of FOXO3a and miRNA-145 in the regulation of transcription. This study highlights the differential outcome at the cellular level when treated with the serum of the same patient pre and post RTX therapy and for the first time mechanistically describes the effect of RTX.

Effectiveness of treatments in Neuromyelitis optica to modify the course of disease in adult patients. Systematic review of literature

BACKGROUND

Neuromyelitis Optica spectrum disorder (NMOSD) is an inflammatory disease, which manifests mostly as recurrent episodes of optic neuritis or myelitis that cause important disability. Early diagnosis and prompt initiation of immunosuppressive therapy are crucial in reducing relapses, disability, and mortality. Even though, there are few prospective randomized controlled trials, several drugs have proved to be both effective and safe. Azathioprine and Rituximab represent the standard of care and are used as first-line treatment agents worldwide. However, recent studies have unveiled new therapies, such as monoclonal antibodies. To make treatment recommendations and management guidelines, it is imperative to define an appropriate standard of care.

METHODS

A systematic literature review was performed in MEDLINE, EMBASE, and LILACS databases using the following terms: "(NMO OR Devic OR Neuromyelitis Optica) AND (Azathioprine OR Prednisone OR Rituximab OR Tocilizumab OR Bortezomib OR Inebilizumab OR Eculizumab OR Satralizumab)" including both, randomized clinical trials and observational studies published between January 2006 and January 2021. The inclusion criteria comprised patients aged 18 or older, NMOSD diagnosis following the Wingerchuck criteria, two or more therapies been compared, and the evaluation of both efficacy and safety outcomes. All studies comparing treatment only with placebo were excluded. Quality was assessed according with the design of the study, and results were synthesized through comparative tables for each outcome evaluated, differentiating the results of randomized and non-randomized studies.

RESULTS

Thirteen studies with 1447 patients were included. Twelve studies evaluated the expanded disability status scale (EDSS) before and after treatment; in five of seven evaluating rituximab, it outperformed its comparators in improving the disability degree. Eleven studies assessed the annual relapse rate (ARR). Again, in six of seven evaluating rituximab, it was superior to other therapies. Time to relapse (TTR) was reported in five studies. The three studies that included Rituximab revealed a longer time to relapse in this arm of treatment. Finding were consistent in randomized and non-randomized studies. The new molecules Satralizumab, Eculizumab and Tocilizumab were evaluated in one study each, proving to be highly effective and safe. The safety profile analysis showed a higher number of adverse events for Azathioprine.

DISCUSSION

This systematic review demonstrates a superiority tendency of Rituximab upon the other treatments strengthening the available evidence about NMOSD management. Superiority in EDSS outcomes, annual relapse rate, time to first relapse and relapses during treatment time was evidenced in the Rituximab group compared to other medications, with lower rates of adverse events. New molecules Tocilizumab, Eculizumab and Satralizumab also showed superiority in the evaluated results, especially in the relapses during treatment time outcome, although with subtle differences in EDSS and ARR outcomes.

CONCLUSION

Our results suggest that monoclonal antibodies are highly effective and safe for the treatment of NMOSD; Rituximab showed better performance on multiple outcomes and has more evidence available. New molecules: Eculizumab, Tocilizumab, Satralizumab are good options for treatment. Drugs like Azathioprine and Mycophenolate are effective, but with a worse risk-benefit ratio, therefore, they are useful alternatives in places that do not have access to monoclonal antibodies.

Efficacy and safety of azathioprine for neuromyelitis optica spectrum disorders: A meta-analysis of real-world studies

OBJECTIVE

This study aimed to perform a meta-analysis of the efficacy and safety of azathioprine (AZA) for neuromyelitis optica spectrum disorders (NMOSD), considering the potential predictive factors related to patient response to AZA in this disease.

METHODS

We performed a systematic online query in PubMed, EMBASE, The Cochrane Library, ClinicalTrials.gov, China National Knowledge Infrastructure, WANFANG DATA, and CQVIP DATA. The available studies on the use of AZA in NMOSD patients were included.

RESULTS

We analyzed a total of 21 studies including 1016 patients. Results demonstrated that AZA significantly decreased annual relapse rate (ARR) by 1.164 (95% confidence intervals (CI), -1.396 to -0.932; p < 0.001). Subgroup analysis showed that AZA significantly decreased ARR in both low-dose group (effect size (ES): -1.545) and moderate-dose group (ES: -2.026). AZA therapy also resulted in a significant reduction of 1.117 (95% CI: -1.668 to -0.566; p < 0.001) in expanded disability status scale (EDSS) score. AZA did not affect EDSS score in the low-dose subgroup (ES: -0.535; p = 0.209) or the moderate-dose subgroup (ES: -0.709; p = 0.064). During AZA therapy, 47% of patients did not experience any relapses (95% CI, 39% to 54%). In addition, 13% of patients developed leukopenia, 11% had elevated liver enzyme levels, 8% experienced nausea or vomiting, 5% developed pancytopenia and 6% died during follow-up.

CONCLUSION

AZA is effective in reducing relapse and improving patients' neurological function. However, liver function monitoring and routine blood monitoring remain necessary. Within the safe upper limit, a higher dose of AZA may be associated with a better efficacy for NMOSD.