Elevated serum interleukin-18 levels might reflect the high risk of hospitalization in patients on peritoneal dialysis.
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.
Yano
Ai
A
Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine and Dentistry, Japan. ai_love_slk@hotmail.com
Nakao
Kazushi
K
Sarai
Ai
A
Akagi
Shigeru
S
Kihara
Takashi
T
Morimoto
Hisanori
H
Nakamura
Akihiko
A
Hiramatsu
Makoto
M
Nagake
Yoshio
Y
Makino
Hirofumi
H
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
D015415:Biomarkers; D018836:Inflammation Mediators; D020382:Interleukin-18; D001613:beta 2-Microglobulin; C018524:N,N-dimethylarginine; D001120:Arginine