title: High mobility group box 1 in patients with 2009 pandemic H1N1 influenza-associated encephalopathy.
abstract: BACKGROUND
  Patients with 2009 pandemic H1N1 influenza-associated encephalopathy (pIE) have been reported in Japan. The most common clinical symptoms of this condition are seizures and progressive coma with high-grade fever. We previously highlighted the cytokine profile of pIE; our results suggest that proinflammatory cytokines play an important role in the pathogenesis. High mobility group box 1 (HMGB1) protein is a late mediator of inflammation or sepsis. However, there are few reports regarding the serum and cerebrospinal fluid (CSF) levels of HMGB1 in pIE patients.
  
  
  METHODS
  We measured serum and CSF levels of HMGB1 in the following: pIE patients with poor outcomes, pIE patients without neurological sequelae, influenza patients without pIE, and control subjects.
  
  
  RESULTS
  Serum HMGB1 levels were significantly higher in pIE patients with poor outcomes compared to those without neurological sequelae. In contrast, there was no difference in CSF HMGB1 levels among all groups. Regarding pIE patients, we found a significant positive correlation between HMGB1 levels and IL-6 in the serum but not in the CSF.
  
  
  CONCLUSIONS
  Our results suggest that HMGB1 protein may be involved in the pathogenesis of pIE and that a high serum, but not CSF, level of inflammatory cytokines plays an important role in the severity of pIE.
authors.affiliation: Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Momonaka
authors.affiliation: Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan. Electronic address: shunji@yamaguchi-u.ac.jp.
authors.forename: Shunji
authors.initials: S
authors.lastname: Hasegawa
authors.affiliation: Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsushige
authors.affiliation: Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Inoue
authors.affiliation: Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Kajimoto
authors.affiliation: Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Okada
authors.affiliation: Department of Pediatrics, Toyoura Hospital, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakatsuka
authors.affiliation: Department of Pediatrics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Morishima
authors.affiliation: Department of Pediatrics, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ichiyama
mesh_terms: D000293:Adolescent; D000328:Adult; D001927:Brain Diseases / Q000097:blood* / Q000134:cerebrospinal fluid* / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D024243:HMGB1 Protein / Q000097:blood* / Q000134:cerebrospinal fluid*; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications*; D015850:Interleukin-6 / Q000097:blood / Q000134:cerebrospinal fluid; D008297:Male; D011379:Prognosis; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D024243:HMGB1 Protein; C585491:HMGB1 protein, human; C508600:IL6 protein, human; D015850:Interleukin-6
keywords: 2009 Pandemic H1N1 influenza; Encephalopathy; HMGB1; IL-6