title: Guillain-Barré syndrome and influenza virus infection.
abstract: BACKGROUND
  In Western countries, the cause of 60% of all Guillain-Barré syndrome (GBS) cases remains unidentified. The number of cases of unidentified cause peaks in winter, and these cases are commonly preceded by respiratory tract infection or influenza-like illness. We investigated the triggering role of influenza virus infection.
  
  
  METHODS
  Of 405 patients with GBS who were admitted to a French reference center during 1996-2004, 234 had cases caused by an unidentified agent. We used time-series methods to study the correlation between the monthly incidence of such cases and influenza-like illnesses reported by the Sentinelles surveillance network. We analyzed anti-influenza antibodies using complement fixation testing and hemagglutination-inhibition assays. We studied etiological subgroups using Wilcoxon and Fisher's exact tests.
  
  
  RESULTS
  We found a positive association between the monthly incidence of GBS caused by an unidentified agent and reported influenza-like illnesses. Of 73 patients whose cases occurred during periods in which there was a possible link to influenza, 10 (13.7%) had serological evidence of recent influenza A, and 4 (5.5%) had serological evidence of influenza B. Eight of 10 influenza A-related cases occurred during "major" influenza seasons, and antibodies specific to the current epidemic strain were found in 9 cases. Most patients with influenza A-related cases were aged < 65 years, and none had antiganglioside antibodies. Influenza-related cases differed both from Campylobacter jejuni-related cases, with regard to the lack of need for mechanical ventilation (P = .014), and from the cases caused by an unidentified agent, with regard to the presence of preceding influenza-like illness or respiratory tract infection (P = .015) and longer time from the infectious event to GBS onset (P = .04).
  
  
  CONCLUSIONS
  Influenza viruses are infrequent triggering agents of GBS but may play a significant role during major influenza outbreaks. Influenza-related GBS displays specific features and is not associated with antiganglioside antibody response, which suggests the presence of underlying immune mechanisms.
authors.affiliation: Laboratoire de Microbiologie, Hôpital Ambroise Paré, Assistance Publique-Hôpitaux de Paris (AP-HP), Boulogne-Billancourt, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Sivadon-Tardy
authors.forename: David
authors.initials: D
authors.lastname: Orlikowski
authors.forename: Raphaël
authors.initials: R
authors.lastname: Porcher
authors.forename: Tarek
authors.initials: T
authors.lastname: Sharshar
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Durand
authors.forename: Vincent
authors.initials: V
authors.lastname: Enouf
authors.forename: Flore
authors.initials: F
authors.lastname: Rozenberg
authors.forename: Christiane
authors.initials: C
authors.lastname: Caudie
authors.forename: Djillali
authors.initials: D
authors.lastname: Annane
authors.forename: Sylvie
authors.initials: S
authors.lastname: van der Werf
authors.forename: Pierre
authors.initials: P
authors.lastname: Lebon
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Raphaël
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Gaillard
authors.forename: Elyanne
authors.initials: E
authors.lastname: Gault
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D003168:Complement Fixation Tests; D005260:Female; D005602:France; D005732:Gangliosides / Q000276:immunology; D020275:Guillain-Barre Syndrome / Q000453:epidemiology / Q000209:etiology*; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D015994:Incidence; D009980:Influenza A virus / Q000302:isolation & purification; D009981:Influenza B virus / Q000302:isolation & purification; D007251:Influenza, Human / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012621:Seasons; D013223:Statistics as Topic
chemical_list: D000914:Antibodies, Viral; D005732:Gangliosides