title: Interleukin-18 is a strong predictor of hospitalization in haemodialysis patients.
abstract: BACKGROUND
  Morbidity and mortality rates are high among patients with end-stage renal disease (ESRD), and recent evidence suggests that this may be linked to inflammation. Current research has also demonstrated the crucial involvement of interleukin-18 (IL-18) in inflammation. In agreement, the activity of IL-18 has been markedly up-regulated in ESRD patients. However, it has not been established whether elevated plasma IL-18 predicts outcome in haemodialysis (HD) patients.
  
  
  METHODS
  To determine whether plasma IL-18 predicts overall hospitalization, we studied 184 ESRD patients (62% males, 58.5+/-1.0 years of age) undergoing maintenance HD treatment. The patients were followed for 12 months and were stratified by the tertiles of plasma IL-18 levels. Classic factors, such as age, body mass index, duration of HD, nutritional and inflammatory parameters, co-morbidity, dialysis adequacy, and lipid status were entered into a Cox regression model to predict hospitalization. The Kaplan-Meier method was used to analyse the cumulative proportion of hospitalization-free events.
  
  
  RESULTS
  Significantly different hospitalization days and frequencies (P<0.05) were observed when patients were divided according to tertiles of plasma IL-18 levels. Patients were stratified according to IL-18 tertiles and analysed separately according to the hospitalization-free period. In the Kaplan-Meier model, the upper tertile of IL-18 had the highest probability of a hospitalization event during the entire follow-up period (P log rank = 0.027). In the Cox proportional hazard model, the relative risk for first hospital admission for each increase in Ln IL-18 (pg/ml) concentration was associated with a 1.709 (95% CI, 1.114 to 2.620; P = 0.014) increase in the risk for future hospitalization events.
  
  
  CONCLUSIONS
  The present study demonstrated a strong predictive value of elevated IL-18 levels for poor outcome in HD patients.
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Chih-Kang
authors.initials: CK
authors.lastname: Chiang
authors.forename: Shih-Ping
authors.initials: SP
authors.lastname: Hsu
authors.forename: Mei-Fen
authors.initials: MF
authors.lastname: Pai
authors.forename: Yu-Sen
authors.initials: YS
authors.lastname: Peng
authors.forename: Tai-I
authors.initials: TI
authors.lastname: Ho
authors.forename: Shing-Hwa
authors.initials: SH
authors.lastname: Liu
authors.forename: Kuan-Yu
authors.initials: KY
authors.lastname: Hung
authors.forename: Tun-Jun
authors.initials: TJ
authors.lastname: Tsai
mesh_terms: D015897:Comorbidity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D020382:Interleukin-18 / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000401:mortality / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies
chemical_list: D020382:Interleukin-18