Abstract 14677: Surgical Thymectomy for Autoimmune Encephalitis With CRMP-5 and AMPAR Antibodies Induced by SARS-CoV-2 Infection

Abstract

Introduction: SARS-CoV-2 has been linked to development of autoimmune diseases. We describe a case of a patient with untreated thymoma who developed 2 cross-reactive autoantibodies between thymus and brain: collapsing response mediator protein-5 (CRMP-5) and alpha-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid receptor (AMPAR), triggered by SARS-CoV-2, inducing encephalitis and coma. Emergency thymectomy reduced anti-CRMP-5 and anti-AMPAR antibodies and restored patient neurologic function within 3 months. Description of Case: A 31-year-old male with a known history of thymoma with myasthenia gravis presented with a 1-day history of memory loss, hallucinations, ataxia, involuntary movements, and tachypnea. Rapid nasal swab COVID-19 test was positive. Over several hours, the patient became unresponsive, requiring urgent intubation for airway protection. Brain computed tomography and magnetic resonance imaging with gadolinium showed no abnormalities. Cerebrospinal fluid (CSF) analysis revealed leukocytosis with lymphocytic predominance. Four days later, CSF and serum were tested for and demonstrated high levels of CRMP-5 and AMPAR antibodies, consistent with autoimmune encephalitis. Complete robotic thymectomy was performed. Pathologic analysis revealed type B2 thymoma with negative resection margins. Three months after surgical intervention, antibody titers normalized, the patient regained consciousness, and had no neurologic deficits. Discussion: Surgical thymectomy effectively treats autoimmune encephalitis in patients with thymoma and positive CRMP-5 and AMPAR antibodies in the setting of SARS-CoV-2 infection. This rare condition is typically seen in patients with thymoma or small cell lung cancer who experience acute viral infection. Although autoantibodies to CRMP-5 and AMPAR are known to be induced by viral infection, this is the first time it has been reported for SARS-CoV-2. Timely surgical intervention is necessary to reverse obtundation and acute encephalitis by removing the cross reactive epitopes in the thymus gland. Future studies are needed to explore the molecular mechanism of SARS-CoV-2 induced immune dysfunction and autoimmunity involving cross-reactive epitopes in this deadly syndrome.