Rituximab in myasthenia gravis: efficacy, associated infections and risk of induced hypogammaglobulinemia

Neuromuscul Disord. 2022 Aug;32(8):664-671. doi: 10.1016/j.nmd.2022.06.006. Epub 2022 Jun 21.


The aim of this study is to evaluate the long-term efficacy, safety, and impact on immunoglobulin G (IgG) levels of rituximab in patients with myasthenia gravis (MG). A retrospective, observational study of drug-refractory MG patients treated with rituximab was done. The MG Foundation of America postintervention status (MGFA-PIS) was used to evaluate clinical response. Serum IgG levels were determined at baseline and post-treatment. Hypogammaglobulinemia was defined as IgG<7g/L. Thirty patients were included, 12 with anti-MuSK and 18 with anti-AChR antibodies. Mean (SD) follow-up was 85.5 (48) months. All 12 MuSK+ patients but only six (33%) AChR+ patients achieved minimal manifestations or remission (p<0.01). Nine severe infections were observed in five patients (17%). One patient was diagnosed with progressive multifocal leukoencephalopathy. At baseline, two patients (2/24; 8%) had hypogammaglobulinemia. During follow-up, hypogammaglobulinemia was observed in 60% (3/5) of patients who developed an infection and in 33% (7/21) who did not. Two of these patients died of infection-related complications. This study supports the effectiveness of rituximab in patients with MG, especially those with anti-MuSK antibodies. Severe infections may appear after rituximab treatment and hypogammaglobulinemia might play a role on it. A standard protocol would be needed to closely monitor IgG levels in MG patients treated with rituximab.

Keywords: Adverse events; Autoimmune; Hypogammaglobulinemia; Infection; Myasthenia gravis; Rituximab.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agammaglobulinemia* / chemically induced
  • Agammaglobulinemia* / drug therapy
  • Humans
  • Immunoglobulin G / therapeutic use
  • Immunologic Factors / adverse effects
  • Myasthenia Gravis*
  • Receptors, Cholinergic
  • Retrospective Studies
  • Rituximab / adverse effects


  • Immunoglobulin G
  • Immunologic Factors
  • Receptors, Cholinergic
  • Rituximab