title: Elevated serum interleukin-18 levels might reflect the high risk of hospitalization in patients on peritoneal dialysis.
abstract: BACKGROUND
  Interleukin (IL)-18 is a potent pro-inflammatory cytokine and plays a central role in atherosclerotic plaque rupture and accelerates atherosclerosis.
  
  
  OBJECTIVE
  The aim of this study was to determine serum IL-18 levels in patients on peritoneal dialysis (PD) and to assess their relationship with hospitalization.
  
  
  METHODS
  Forty-three PD patients and 20 healthy individuals were enrolled in this study. We investigated the relationship of the serum concentrations of IL-18 and other well-established atherosclerotic markers, such as asymmetric dimethylarginine (ADMA). Hospitalization data from over a 18-month period were prospectively obtained on all 43 PD patients. Classic factors were entered into a Cox regression model to predict first hospitalization.
  
  
  RESULTS
  The serum levels of IL-18 in patients on PD were significantly higher than those of healthy individuals (228.5 +/- 140.3 pg/mL vs 154.8 +/- 44.7 pg/mL, P < 0.05, respectively). Furthermore, serum IL-18 levels showed a positive correlation with duration of PD, serum beta2 microglobulin and serum ADMA levels. Mean serum levels of IL-18 were significantly higher among patients who had experienced at least one hospitalization than those who had not (279.9 +/- 164.3 vs 158.5 +/- 43.9 pg/mL, P = 0.0426). Furthermore, the relative risk for first hospitalization for each increase in IL-18 (pg/mL) levels was associated with a 1.182 (95% confidence interval, 1.012-1.364; P = 0.0071) increase in the risk for future hospitalization events.
  
  
  CONCLUSIONS
  The present study suggests the elevated serum IL-18 levels might increase the risk for future hospitalization in patients on PD.
authors.affiliation: Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine and Dentistry, Japan. ai_love_slk@hotmail.com
authors.forename: Ai
authors.initials: A
authors.lastname: Yano
authors.forename: Kazushi
authors.initials: K
authors.lastname: Nakao
authors.forename: Ai
authors.initials: A
authors.lastname: Sarai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Akagi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kihara
authors.forename: Hisanori
authors.initials: H
authors.lastname: Morimoto
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nakamura
authors.forename: Makoto
authors.initials: M
authors.lastname: Hiramatsu
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nagake
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Makino
mesh_terms: D000368:Aged; D001120:Arginine / Q000031:analogs & derivatives / Q000097:blood; D050197:Atherosclerosis / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006760:Hospitalization; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D020382:Interleukin-18 / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D008297:Male; D010530:Peritoneal Dialysis; D012307:Risk Factors; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D020382:Interleukin-18; D001613:beta 2-Microglobulin; C018524:N,N-dimethylarginine; D001120:Arginine