Autoimmune Encephalitis with Antibodies Against A-Amino-3hydroxy-5-Methyl-4-Isoxazolepropionic Acid Receptor and γ-Aminobutyric Acid-Beta Receptor: Case Report.

Introduction: Limbic encephalitis is a rapidly progressing disease that presents with seizures, psychiatric symptoms, and recent memory loss. Detection of more than one autoantibody is a rare condition in this disease where an underlying autoantibody is frequently detected. Although different autoantibodies have been reported in the literature, no case has been reported regarding the association of anti-γ-aminobutyric acid-beta-receptor (anti-GABA_BR) and anti-α-amino-3 hydroxy-5-methyl-4-isoxazolepropionic acid (anti-AMPAR).

Case: In this presentation, a 46-year-old female patient with subacute development of short-term memory loss and behavioral symptoms will be described. Anti-GABA_BR and anti-AMPAR were positive in the anti-neuronal antibody panel sent from the cerebrospinal fluid and serum. Small cell lung cancer was detected as a result of malignancy screening tests. The patient's complaints and autoantibody positivity regressed after immunotherapy.

Conclusion: In this case report, a case with coexistence of anti-GABA_BR and anti-AMPAR antibodies, which has not been previously reported in the literature, is described. As more cases with the coexistence of these two antibodies are detected, knowledge on clinical aspect, laboratory and treatment will increase.