News Releases & Research Results IRAK4 deficiency presenting with anti-NMDAR encephalitis in infancy - Relationship between early-onset anti-NMDAR encephalitis and genetic immune disorders -

The results of collaborative research conducted by Professor Satoshi Okada, Professor Emeritus Masao Kobayashi, and Graduate Student Shiho Nishimura of the Department of Pediatrics, Graduate School of Biomedical and Health Sciences, Hiroshima University and Tokyo Medical and Dental University, Gifu University, University of Tsukuba, Kazusa DNA Research Institute, and St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller University.

• IRAK4 deficiency (*1) presenting with anti-NMDAR encephalitis (*2) was found for the first time in the world. Through the analysis of this case, an assay for conveniently and accurately evaluating the pathological significance of IRAK4 gene mutations was successfully established.
  (*1) A rare disease caused by IRAK gene mutations, with about 10 familial cases identified in Japan. This disease causes severe infections (e.g., Streptococcus pneumoniae and Staphylococcus) in infancy, with a high mortality rate.
  (*2) Encephalitis characterized by psychiatric symptoms, such as anxiety, depression, and hallucinations and delusions, accompanied by convulsions, central hypoventilation, and prolonged consciousness disorder in severe cases.
• The results of this research project should facilitate the elucidation of host factors for anti-NMDAR encephalitis mainly in young-onset cases.

This program was conducted with the support of the Practical Research Project for Rare/Intractable Diseases by AMED.

The results were published in the Journal of Clinical Immunology on October 21.

Nishimura S., et al. IRAK4 deficiency presenting with anti-NMDAR encephalitis and HHV6 reactivation Journal of Clinical Immunology
DOI: 10.1007/s10875-020-00885-5