IL18 and heart failure: It was then demonstrated in humans that the urinary concentration of IL-18 was higher in ATN when compared with other causes of renal insufficiency such as hypovolemia, heart failure, urinary tract infections and chronic renal failure (n = 72).99 In the same study, the urinary IL-18 level at 24 hours after kidney graft was also much higher in patients who later developed delayed graft dysfunction.