title: Influenza-associated encephalopathy with elevated antibody titers to pandemic (H1N1) 2009 influenza.
abstract: Pandemic H1N1 influenza (pH1N1) has been associated with encephalopathy, but the role of adaptive immunity in disease pathogenesis remains unclear. A child presented with seizures 5 days after onset of respiratory symptoms with pH1N1, with no detectable virus in cerebrospinal fluid. The authors compared her serum cytokines and pH1N1 antibody titers to those of 22 children with pH1N1, seasonal influenza, or other respiratory viral infections. They also compared her cerebrospinal fluid biomarkers to those of 20 children with confirmed or probable central nervous system infection or viral infection without central nervous system involvement. Her serum antibody titers were several-fold higher, and levels of proinflammatory cytokines in cerebrospinal fluid and serum were lower than those of controls. Antibody titers in cerebrospinal fluid were undetectable. The delayed onset of neurologic manifestations, normal cytokine levels in serum and cerebrospinal fluid, markedly elevated hemagglutinating and neutralizing antibody titers, and absence of virus and antibodies in cerebrospinal fluid raise the possibility of a post-infectious autoimmune-mediated process.
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Nisha
authors.initials: N
authors.lastname: Thampi
authors.forename: Ari
authors.initials: A
authors.lastname: Bitnun
authors.forename: David
authors.initials: D
authors.lastname: Banner
authors.forename: Thomas
authors.initials: T
authors.lastname: Rowe
authors.forename: David J
authors.initials: DJ
authors.lastname: Kelvin
authors.forename: Susan E
authors.initials: SE
authors.lastname: Richardson
authors.forename: Patricia
authors.initials: P
authors.lastname: Parkin
authors.forename: Dat
authors.initials: D
authors.lastname: Tran
mesh_terms: D002675:Child, Preschool; D016207:Cytokines / Q000097:blood; D018792:Encephalitis, Viral / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications / Q000209:etiology*; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology / Q000472:pathogenicity*; D007251:Influenza, Human / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications* / Q000276:immunology*; D008279:Magnetic Resonance Imaging
chemical_list: D016207:Cytokines