Serum Interleukin-18 level as a Marker for the Diagnosis of Hepatorenal Syndrome

Background: Hepatorenal syndrome (HRS) is a serious complication of decompensated cirrhosis and is associated with high mortality if not promptly recognized and treated. Reliable biomarkers are urgently needed to allow for earlier and more accurate diagnosis of HRS, as it is currently a diagnosis of exclusion. A member of the interleukin-1 family of proinflammatory cytokines, interleukin-18 (IL-18) is an essential component of immunological and inflammatory reactions. The purpose of this research was to determine if serum IL-18 is a useful diagnostic tool for detecting HRS in chronic liver disease (CLD) patients. Methods: This cross-sectional study included 90 patients with CLD, comprising 45 patients with HRS and 45 without, recruited from Tanta University and Kafr El-Sheikh Liver and Heart Research Center, Egypt, between October 2023 and September 2024. All participants underwent comprehensive clinical evaluation, abdominopelvic ultrasonography, and laboratory investigations, including measurement of serum IL-18 levels using enzyme-linked immunosorbent assay. Results: Median serum IL-18 levels did not differ significantly between patients with HRS and those without HRS (p = 0.126). Receiver operating characteristic analysis demonstrated poor diagnostic accuracy for HRS, AUC=0.594, a sensitivity of 68.9%, and specificity of 46.7%. Serum IL-18 levels were not significantly associated with hepatic encephalopathy or hepatocellular carcinoma. However, IL-18 showed positive correlations with hemoglobin, white blood cell count, and serum bilirubin levels, indicating that circulating IL-18 more likely reflects systemic inflammatory activity rather than HRS-specific renal injury. Conclusion: Serum IL-18 lacks sufficient diagnostic accuracy to serve as a reliable biomarker for HRS in patients with CLD.