Case report: Astrocytoma coexisting with serum glycine receptor 1 antibody

Antibody against glycine receptor 1 (GlyR1) is frequently detected in autoimmune encephalitis, where they primarily manifest as stiff- person syndrome syndrome or progressive encephalomyelitis with rigidity and myoclonus and epilepsy. While GlyR1 antibody positivity is often associated with thymomas, B-cell lymphoma, Hodgkin lymphoma, breast cancer, and small cell lung cancer, its association with glioma has not been reported to date. We report a 47-year-old male patient who presented with acute symptomatic seizures and lesions in the left temporal and hippocampus are typically detected by magnetic resonance imaging. Antibodies related to autoimmune encephalitis was tested positive for GlyR1 receptor antibodies in serum (titer is 1:30) but not in cerebrospinal fluid. The patient underwent resection of a left cerebral hemisphere lesion, which was pathologically diagnosed as astrocytoma, and carried out radiotherapy and chemotherapy. Without postoperative immunotherapy, the patient remained free of epileptic symptoms following oral sodium valproate antiepileptic treatment. We thus attributed the epilepsy to astrocytoma rather than GlyR antibody-associated autoimmune encephalitis. Due to poor immunity after radiotherapy and chemotherapy for the tumor, the patient suffered from status epilepticus and multiple organ failure, and eventually passed away. This case is the first to report the coexistence of GlyR antibodies and glioma, revealing the association between autoimmune antibodies and tumors. In the future, more research needs to focus on the mechanism underlying their coexistence.