Worsening of the EDSS score after rituximab was observed in only four patients.[31] Graves em et al /em . We performed a comprehensive review of all studies that evaluated clinical and paraclinical effects of rituximab on NMO. MEDLINE-PubMed, Web of Sciences, EMBASE, and Cochrane databases up to June 2016 included in our searches. In addition, reference lists from articles identified by search as well as a key review article to identify additional articles included in the study. Rituximab targets the CD20 antigen on B-cells and decreases attack frequency and severity in patients with NMO; however, it does not remove PU-H71 attacks, even when modifying treatment to achieve B-cell depletion. Most of the investigations revealed that EDSS significantly in all patients with rituximab treatment will be decreased after treatment with rituximab. No new or enlarged lesions or pathological gadolinium enhancement was observed in serial brain and spinal cord magnetic resonance imaging, except for those observed concomitantly with clinical relapses and the median length of spinal cord lesions was significantly reduced after therapy. Rituximab targets the CD20 antigen and decreases attack frequency and severity in patients with NMO. strong class=”kwd-title” Keywords: CD20 antibody, neuromyelitis optica, rituximab INTRODUCTION Neuromyelitis optica (NMO) is a severe autoimmune disorder of the central nervous system (CNS) which is predisposed to the optic nerves and spinal cord. Traditionally, neurologists, particularly in Asian nations, believed NMO to be a subtype of multiple sclerosis (MS), whereas others considered it a distinct disease.[1] NMO, similar to various other autoimmune disorders, is predominant in women (4:1C9:1 in most studies).[2] The median age of onset is 30C40 years, but IL-1RAcP adults older than 65 years and children may also be affected.[3] A major development was the discovery that most patients with NMO have detectable serum antibodies that target the water channel aquaporin-4 ([AQP4]-immunoglobulin G [IgG]), are highly specific for clinically diagnosed NMO, and have pathogenic potential. Despite the use of sensitive evaluates, AQP4-specific antibodies are not found in 10%C40% of patients diagnosed with NMO or NMO spectrum disorders (NMOSDs).[4] For this purpose, anti-myelin oligodendrocyte glycoprotein antibodies have been identified in several PU-H71 patients with clinical features of NMOSD, but who are lacking anti-AQP4 antibodies.[5] A widespread spectrum of clinical features, consisting of recurrent optic neuritis (ON), longitudinally extensive transverse myelitis (LETM), and some encephalitic presentations, are renowned as the spectrum is referred to as NMOSD. A majority of the patients with NMO experience a relapsing progressive course resulting in disability. Multiple therapeutic agents have been used with different results. Recent evidence points to B-cell-mediated humoral immunity in the pathogenesis of NMO. The CD20 molecule is a transmembrane protein expressed on a broad range of cells of the human B-cell lineage, from pre-B-cells through naive and memory B-cells. Rituximab (Rituxan, Genentech and Biogen Idec, RTX) signifies the first genetically engineered chimeric anti-CD20 monoclonal antibody (mAb) that was found to target and proficiently reduce circulating CD20+ B-cells in humans. A developing concentration in the potential benefits of targeting B-cells in nonneoplastic disorders has led to clinical trials of rituximab in several peripheral and CNS disorders including MS and NMO. However, its definite efficacy and safety have not yet been clarified. The aim of our study was to review clinical trials to elucidate the impact of rituximab on the relapse rate, magnetic resonance imaging (MRI) findings, Expanded Disability Status Scale (EDSS), and progression of disability in NMO. METHODS Two of us (ME and MS) independently searched the MEDLINE, Central Register of Controlled Trials, and clinicaltrials.gov databases (published between January 1, 2000, and July 31, 2015) using the terms NMO, rituximab, Devic’s disease, and PU-H71 mAb. A comprehensive literature search was performed by two authors with expertise in neurology, clinical epidemiology, and systematic review methodology. Review articles and references of all papers were overviewed for potentially relevant studies. Inclusion criteria The following criteria were used to include studies NMO was defined according to accepted international diagnostic criteria Efficiency and tolerability of MS were calculated Papers were published in English..