title: Circulating interleukin 6 and interleukin 10 in community acquired pneumonia.
abstract: BACKGROUND
  Inflammatory cytokine concentrations correlate with severity of sepsis. We hypothesised that patients with community acquired pneumonia (CAP) associated with systemic inflammatory response syndrome (SIRS) would have greater interleukin 6 (IL-6) production due to activation of the inflammatory cytokine cascade, matched by a significant anti-inflammatory cytokine response. Interleukin 10 (IL-10) was evaluated as a potential surrogate marker of severity of sepsis in CAP and age related impairment of the cytokine response was studied in elderly patients with CAP.
  
  
  METHODS
  Circulating immunoreactive IL-6 and IL-10 levels were measured in 38 patients with CAP subdivided into a group fulfilling the criteria for SIRS (n = 28) and a non-SIRS group (n = 10) in a variety of age groups and correlated with APACHE II scores.
  
  
  RESULTS
  80% had circulating IL-6 levels (median 46.7 pg/ml, range 4.6-27,000) and 60% had circulating IL-10 levels (median 15.5 pg/ml, range 2.5-765). Concentrations of both were significantly increased in patients with SIRS compared with non-SIRS patients. Those with activation of the inflammatory cytokine cascade (IL-6 positive) produced more IL-10 than IL-6 negative patients. Older patients had a similar cytokine response. Both cytokines correlated positively with APACHE II scores.
  
  
  CONCLUSIONS
  This is the first demonstration of circulating IL-10 in CAP. A greater counter-inflammatory response in patients with SIRS and in IL-6 positive patients suggests a potential immunomodulatory role for IL-10 in controlling the inflammatory cytokine response in CAP. IL-10 concentrations correlate with severity of illness in CAP and may be of prognostic importance. There is no age related impairment in the cytokine response.
authors.affiliation: Beaumont Hospital, Dublin, Ireland.
authors.forename: P
authors.initials: P
authors.lastname: Glynn
authors.forename: R
authors.initials: R
authors.lastname: Coakley
authors.forename: I
authors.initials: I
authors.lastname: Kilgallen
authors.forename: N
authors.initials: N
authors.lastname: Murphy
authors.forename: S
authors.initials: S
authors.lastname: O'Neill
mesh_terms: D018806:APACHE; D000328:Adult; D017677:Age Distribution; D000368:Aged; D017714:Community-Acquired Infections / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D008875:Middle Aged; D011014:Pneumonia / Q000378:metabolism*; D018746:Systemic Inflammatory Response Syndrome / Q000378:metabolism*
chemical_list: D015850:Interleukin-6; D016753:Interleukin-10