title: Serum levels of interleukin 6 in recently hospitalized tick-borne encephalitis patients correlate with age, but not with disease outcome.
abstract: Infection with many encephalitic viruses is associated with the induction of the proinflammatory cytokine interleukin (IL)-6. In some situations, induction of high levels of this cytokine is associated with a protective response, but in others it can be linked to tissue damage and disease. In the studies reported here, levels of serum IL-6 and virus-specific antibodies were measured on admission to hospital and correlated with clinical outcomes. Only some patients demonstrated raised levels of serum IL-6, and there was no correlation between high levels of this cytokine and either gender or the severity of clinical disease. A statistically significant association between raised IL-6 and age was observed, with all individuals below the age of 26 showing normal levels of serum IL-6, regardless of clinical presentation. Furthermore, not all patients had detectable levels of virus-specific serum immunoglobulin G (IgG) antibodies, but an inverse and statistically significant correlation between raised IL-6 levels and IgG titre was observed. Consequently, serum levels of IL-6 cannot be used as a reliable indicator of disease outcome.
authors.affiliation: City Centre of Endemic Infections, Eikatherinburg, Russia.
authors.forename: M G
authors.initials: MG
authors.lastname: Toporkova
authors.forename: S E
authors.initials: SE
authors.lastname: Aleshin
authors.forename: S V
authors.initials: SV
authors.lastname: Ozherelkov
authors.forename: M V
authors.initials: MV
authors.lastname: Nadezhdina
authors.forename: J R
authors.initials: JR
authors.lastname: Stephenson
authors.forename: A V
authors.initials: AV
authors.lastname: Timofeev
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D015415:Biomarkers / Q000097:blood; D004669:Encephalitis Viruses, Tick-Borne / Q000276:immunology; D004675:Encephalitis, Tick-Borne / Q000276:immunology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011379:Prognosis
chemical_list: D000914:Antibodies, Viral; D015415:Biomarkers; D007074:Immunoglobulin G; D015850:Interleukin-6