Rituximab in AChR subtype of myasthenia gravis: systematic review

Abstract

Myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction characterised by an autoantibody against acetylcholine receptor (AChR-Ab), autoantibody against muscle-specific kinase (MuSK-Ab), lipoprotein-related protein 4 or agrin in the postsynaptic membrane at the neuromuscular junction. Many patients are resistant to conventional treatment and effective therapies are needed. Rituximab (RTX) is a monoclonal antibody directed against CD20 antigen on B cells which has been successfully employed in anti-MuSK-Ab+MG, but the efficacy in anti-AChR-Ab+MG is still debated. The purpose of this systematic review was to describe the best evidence for RTX in the acetylcholine receptor subtype. The authors undertook a literature search during the period of 1999–2019 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analys methodology, employing (myasthenia)+(gravis)+(RTX) as search terms. The analysis was confined to studies that include at least five patients with confirmed anti-AChR-Ab+MG. Thirteen studies have been selected, showing a good safety. The data obtained were heterogeneous in terms of posology, administration scheme and patients’ evaluation, ranging from a minimum of two to a maximum of three cycles. RTX led to a sustained clinical improvement with prolonged time to relapse, in parallel to a reduction or discontinuation of other immunosuppressive therapies. Treatment with RTX appears to work in some but not all patients with anti-AChR-Ab+MG, but randomised controlled trials are needed. Future studies should take into account the subtype of MG and employ reliable measures of outcome and severity focusing on how to identify patients who may benefit from the treatment. Trial registration number: NCT02110706.

A Practical Approach to Managing Patients With Myasthenia Gravis—Opinions and a Review of the Literature

“…It would be crucial for biomarkers to be developed that will allow physicians to predict a patient's response to Rituximab. There is also a similar crucial need for robust trial data for this drug, since the efficacy of Rituximab in AChR-MG is still debatable and the studies that are available may be limited by an element of reporting bias (119). This data will also help physicians counsel patients adequately when embarking on this therapy.…”

Significant reduction of physical activity in patients with neuromuscular disease during COVID-19 pandemic: the long-term consequences of quarantine

“…familial amyloid neuropathies, chronic inflammatory demyelinating polyradiculoneuropathy). Moreover, patients with neuromuscular disease (NMD) require strict follow-up, essential immunotherapies, muscle rehabilitation and physical exercise [14][15][16][17][18][19][20]. In particular, NMD need an active physical activity (PA), through the practice of regular exercise, to improve muscle strength, endurance ability and to prevent osteoarticular complications from disuse [15,17,21].…”

Myasthenia Gravis With Antibodies Against Muscle Specific Kinase: An Update on Clinical Features, Pathophysiology and Treatment

“…Refractory MG patients, in whom at least two independent immunosuppressive treatments have been carried out at therapeutic dosage without benefit in controlling the disease, should be considered for treatment with rituximab, a monoclonal chimeric IgG1 that depletes B lymphocytes through specific binding to the CD20 transmembrane antigen (Maddison et al, 2011 ; Kaegi et al, 2019 ; Di Stefano et al, 2020 ). In MuSK-MG patients, rituximab treatment appears to be particularly effective and this could be because IgG4 antibodies sustain the main pathogenic mechanism of the disease.…”