title: Excessive increase of serum interleukin 6 jeopardizes host defense against multi-bacterial infection.
abstract: Serum interleukin 6 (IL-6) is elevated among patients who have undergone surgery, trauma, and thermal injury. It is well known that the greater the increase of serum IL-6, the higher the incidence of post-injury morbidity and mortality is. However, it has not been determined whether the physiological effects of IL-6 increase the rate of morbidity and mortality or if IL-6 is just a bystander that only indicates the severity of the injury. To elucidate this, we planned to investigate the effect of IL-6 on a multi-bacterial infection, one of the most frequent post-injury complications. CDF1 male mice were administered recombinant human IL-6 (hIL-6) continuously at a dose of 0, 1, or 10 microg/day. The mice then underwent cecal ligation without puncture that induced slow multi-bacterial infection. The survival rate of mice receiving 10 microg/day of hIL-6 was significantly lower (38.5%) than the rate of those receiving 0 (83.3%) or 1 (92.3%) microg/day of hIL-6. The result of this study showed that only excessive increases in serum IL-6, to levels that were observed among patients who underwent severe injury or extensive surgery with high incidence of post-injury infection, jeopardize the host's defense against bacterial infection.
authors.affiliation: Department of Surgery, Omiya Medical Center, Jichi Medical School, 1-847 Amanuma, Saitama Saitama-city 330-0834, Japan. soda@omiya.jichi.ac.jp
authors.forename: Kuniyasu
authors.initials: K
authors.lastname: Soda
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Kano
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kawakami
authors.forename: Fumio
authors.initials: F
authors.lastname: Konishi
mesh_terms: D000818:Animals; D001424:Bacterial Infections / Q000097:blood / Q000276:immunology*; D001835:Body Weight / Q000187:drug effects; D002432:Cecum / Q000601:surgery; D004822:Epididymis / Q000187:drug effects; D015850:Interleukin-6 / Q000008:administration & dosage / Q000097:blood* / Q000276:immunology; D008026:Ligation; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009929:Organ Size / Q000187:drug effects; D010538:Peritonitis / Q000401:mortality; D010976:Platelet Count; D011677:Punctures; D011994:Recombinant Proteins / Q000008:administration & dosage; D015996:Survival Rate
chemical_list: D015850:Interleukin-6; D011994:Recombinant Proteins