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

Abstract

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.

• Authors: Marta Caballero-Ávila, Rodrigo Álvarez-Velasco, Esther Moga, Ricard Rojas-Garcia, Janina Turon-Sans, Luis Querol, Montse Olivé, David Reyes-Leiva, Isabel Illa, Eduard Gallardo, Elena Cortés-Vicente
• Journal: Neuromuscular disorders : NMD (Neuromuscul Disord) Vol. 32 Issue 8 Pg. 664-671 (08 2022) ISSN: 1873-2364 [Electronic] England
• PMID: 35811274 (Publication Type: Journal Article, Observational Study, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2022 Elsevier B.V. All rights reserved.

Chemical References

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

Topics

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