Does interleukin-18 play a role in the pathogenesis of hepatic encephalopathy?

ABSTRACT

BACKGROUND/AIMS: It has been suggested that the presence of inflammation may accentuate the neuropsychologic alterations in hepatic encephalopathy (HE). The aim of the study was to investigate any association between alterations in plasma levels of the pro-inflammatory cytokine IL-18 and HE. METHODOLOGY: The study population included 63 patients with cirrhosis and 20 healthy controls. Laboratory data included international normalized ratio, plasma albumin, bilirubin, urea, creatinine, hsCRP and IL-18 (pg/mL). HE was assessed using West Haven criteria and critical flicker frequency (CFF) measurement. RESULTS: Forty-two of the 63 cirrhotic patients had HE (4, 16, 21 and 1 patients in grade 0, 1, 2, 3, respectively). hsCRP and IL-18 were significantly increased in patients with HE compared with the control group (1.6 +/- 4.8 vs 0.5 +/- 0.8, p<0.001 and 121.4 (13.6-2043.6) vs 56.3 (13.0-174.0), p=0.006, respectively). The levels of hsCRP and IL-18 were significantly higher in the all cirrhotic patients than in the control subjects (p=0.002 and p=0.008 respectively). hsCRP was significantly higher in patients with HE (2.2 +/- 6) than in patients without HE (0.7 +/- 1.2) (p=0.013). The levels of IL-18 were found higher in patients with HE than in patients without HE [121.4 (13.6-2043.6) vs 103.8 (13.0-828.0)] but the difference was not significant (p=0.215). IL-18 was higher in patients with elevated hsCRP [124.6 (13.6-2043.6)] compared with those who had normal hsCRP [75.6 (13.0-753.2)] (p=0.029). CONCLUSION: There is an inflammatory response in the presence of cirrhosis and HE; and IL-18 may play a role in the perpetuation of chronic inflammation.