IL18 production and IL18 promoter polymorphisms correlate with mortality in ICU patients.

BACKGROUND Single nucleotide polymorphisms in the promoter of interleukin (IL)-18 (-607C/A and -137G/C) may affect the clinical course of inflammatory diseases. This study examined the relationship between the plasma IL18 levels, IL18 promoter polymorphism, and outcomes in the intensive care unit (ICU) setting. PATIENTS AND METHODS Plasma IL18 levels, IL18 promoter genotype, clinical variables, including APACHE II score, and mortality were examined in 70 ICU patients. RESULTS Plasma IL18 levels were significantly higher in patients who did not survive the ICU stay than in patients who survived, and were correlated with APACHE II score. When examined by IL18 promoter genotype, only patients with the -607CA genotype exhibited differences in IL18 expression between survivors and non-survivors. CONCLUSION Plasma IL18 levels may predict outcome in patients with sepsis. IL18 promoter polymorphism, especially at -607, may increase IL18 production in some patients and might be useful in predicting the outcome of patients with sepsis in the ICU.