AUTHOR=Song Yu , Chen Shanshan , Gao Ju , Lu Jie , Xu Wenwen , Lin Xingjian , Chen Jiu 

TITLE=Case Report: Coexistence of Anti-AMPA Receptor Encephalitis and Positive Biomarkers of Alzheimer's Disease

JOURNAL=Frontiers in Neurology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.673347

DOI=10.3389/fneur.2021.673347

ISSN=1664-2295

ABSTRACT=Anti-α-amino-3-hydroxy-5-methyl-4-lsoxazolepropionic acid (AMPA) receptor encephalitis is a rare autoimmune disease that is characterized by acute cognitive impairment, mental symptoms and seizures. The high comorbidity rate between anti-AMPAR encephalitis and other somatic diseases, such as malignancy, have revealed the possibility of potential co-pathogenesis. However, there have not yet been reports about anti-AMPAR encephalitis with concomitant cerebrospinal fluid (CSF) biomarkers consistent with Alzheimer’s disease (AD). Herein, we present the case of an elderly male patient with autoimmune encephalitis (AE) presenting with anti-AMPA1-R & anti-AMPA2-R antibodies, as well as CSF biomarkers of AD. The patient was hospitalized with acute memory decline for one week. Anti-AMPA1-R & anti-AMPA2-R antibodies were positively detected in CSF, and the anti-AMPA2-R antibody was also present in the serum. Additionally, the biomarkers of AD were concurrently present in CSF (Aβ1-42 245.70 pg/mL, t-Tau 894.48 pg/mL, p-Tau 78.66 pg/mL). After administering a combined treatment of intravenous immunoglobulin and glucocorticoids, the patient recovered significantly and his cognitive function achieved a sustained remission during two months’ follow-up. This case raises the awareness of a possible interaction between AE and changes of CSF biomarkers. We speculated that the existence of AMPA receptor antibodies can induce changes of CSF, and other pathological alterations. This present report highlights that a potential relationship exists among AE, and provides a warning when making the diagnosis of AD.