Case ReviewSevere Relapse of Vaccine-Induced Guillain–Barré Syndrome After Treatment With NivolumabYuen, Carlen MD; Kamson, David MD; Soliven, Betty MD; Kramer, Christopher MD; Goldenberg, Fernando MD; Rezania, Kourosh MDAuthor Information Department of Neurology, University of Chicago Medical Center, Chicago, IL. Reprints: Kourosh Rezania, MD, 5841 South Maryland Avenue, MC 2030, Chicago, IL 60637 (e-mail: [email protected]). The authors report no conflicts of interest. Journal of Clinical Neuromuscular Disease: June 2019 - Volume 20 - Issue 4 - p 194-199 doi: 10.1097/CND.0000000000000230 Buy Metrics Abstract Cancer immunotherapy with checkpoint inhibitors may result in neuromuscular immune-related adverse reactions, including Guillain–Barré syndrome (GBS)-like disease. On the other hand, checkpoint inhibitor therapy may result in exacerbation of underlying autoimmune diseases such as myasthenia gravis and multiple sclerosis. We present a patient who developed a severe and fatal relapse of postvaccination GBS after he was treated with nivolumab, a monoclonal antibody directed to programmed death–1 (PD-1), during a GBS treatment-related fluctuation. We recommend that caution be exercised in starting treatment with PD-1 inhibitors in the acute stage or early in the recovery period of GBS. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.