Urinary IL-18: a marker of contrast-induced nephropathy following percutaneous coronary intervention?

Contrast-induced nephropathy (CIN) is a complication that is underestimated in clinical practice after cardiac catheterization. Recently, the value of interleukin (IL)-18 as a novel biomarker for the detection of acute renal failure has been highlighted. In the present study, we sought to investigate whether urine IL-18 may be an early diagnostic marker of CIN.

We performed a nested case-control study using a hospital based cohort of all patients (n=157) admitted for elective PCI for stable angina to the Uludag University School of Medicine between February 2007 and June 2007. We identified 15 patients (9.5%) with CIN. Controls were matched with cases at an attempted 2.5:1 ratio by age and gender. Urinary IL-18 values were measured before as well as 24 and 72 h after the PCI.

No statistically significant differences in urine IL-18 were detected between cases (n=15) and controls (n=36) or between the patient samples obtained before PCI and after the invasive procedure in both study groups.

These findings argue against the hypothesis that urine IL-18 may be clinically useful as a biomarker of CIN after radiological procedures requiring intravascular administration of iodinated contrast media. Further studies with larger sample sizes are needed to validate our findings.