Abstract Details

Title Etiological Insights of Encephalitis and Encephalitis-like Central Nervous System Diseases: Brain Tissue Metagenomic Next-generation Sequencing

Topic Infectious Disease

Presentation(s) S25 - Diagnostics and Therapies in Infectious Diseases (3:54 PM-4:06 PM)

Poster/Presentation
Number 003

Background Identifying the etiology of central nervous system (CNS) diseases, regardless of their infectious or non-infectious nature, is often intricate. Next-generation sequencing (NGS) has emerged as a powerful tool for sensitive and unbiased screening of tissue or body fluid specimens.

Objective This study aimed to investigate the underlying etiology of CNS diseases in Japanese patients.

Design/Methods Between April 2013 and October 2021, we collected brain tissue samples from 35 patients diagnosed with encephalitis or encephalitis-like CNS diseases, obtained via biopsy or autopsy. We utilized shotgun metagenomics NGS on brain tissues (mNGS-bt) to identify potential pathogens by analyzing non-human sequences against the BLAST nucleotide database. Comprehensive clinical, serological, pathological, and genetic assessments ensured the precision of pathogen identification.

Results Among the 35 patients, mNGS-bt elucidated pathogen-specific genomic sequences in eight cases (22.9%), including halobacteria (two cases), Balamuthia mandrillaris (one case), Epstein–Barr virus (two cases), JC polyomavirus (one case), toxoplasma gondii (one case), and herpes simplex virus (one case). Several cases exhibited concurrent infections with multiple pathogens. Fourteen cases without pathogen sequences, indicative of non-infectious CNS diseases (40%), were diagnosed with neoplastic diseases (seven cases), autoimmune/inflammatory disorders (six cases), and amyloid angiopathy (one case).

Conclusions This study, featuring the most substantial brain tissue sample collection to date, demonstrates that integrating mNGS-bt with comprehensive analyses substantially improves etiological diagnoses, with 62.9% (22/35) of cases attributed to infectious or non-infectious causes. These findings highlight the potential of mNGS-bt as a primary screening tool for patients with encephalitis or encephalitis-like CNS diseases of unknown etiology.

Authors/Disclosures
Yusuke Sakiyama (Department of Neurology and Geriatrics, Kagoshima University Graduate School of) PRESENTER	No disclosure on file
Jun-Hui Yuan	No disclosure on file
Akiko Yoshimura	No disclosure on file
Jun Takei	No disclosure on file
Masahiro Ando	No disclosure on file
Hiroshi Takashima, MD, PhD (Neurology, Kagoshima University)	Dr. Takashima has nothing to disclose.