Amy Kunchok, MD, Cleveland Clinic, Cleveland, OH, discusses a project designed to determine the frequency of detection, as well as age and sex associations, of autoimmune encephalitis antibody biomarkers. Over 42,000 patients were tested in the Mayo Clinic Neuroimmunology Laboratory for antibody markers in serum or cerebral spinal fluid (CSF). The most common antibodies detected in the serum and CSF of adults were NMDA-R-IgG, GAD65-IgG and LGI1-IgG. In the CSF of children, almost 90% who were antibody-positive were positive for NMDA-R-IgG, followed by approximately 9% who were GAD65-IgG positive. NMDA-R-IgG was also the most frequently detected antibody in the serum of children. In contrast to adults, approximately 30% of pediatric patients were positive for MOG-IgG1, highlighting MOG-IgG1 as an emerging biomarker for autoimmune encephalitis in children. Additionally, it was observed that NMDA-R-IgG and GAD65-IgG were associated with female sex and LGI1-IgG associated with male sex. The findings from this study may help to inform clinical practice and advance our understanding of disease pathobiology. This interview took place at the ACTRIMS Forum 2022 in West Palm Beach, Florida.