Abstract: The present disclosure concerns methods of detecting a molecule, interleukin 18, in a sample, and using the detection of IL-18 to predict a condition. In a particular embodiment, the present invention concerns methods of detecting interleukin 18, in a sample, preferably prior to the increase in serum creatinine in a subject predisposed to a condition. In certain embodiments, the methods may comprise obtaining a sample from a subject such as a urine or blood sample and analyzing the sample for the presence or absence of IL-18 to predict a condition for example acute renal failure or organ transplant failure. In another embodiment, the methods may comprise analyzing a sample from a subject for the presence of IL-18 and applying information obtained from analyzing the presence of IL-18 to determine a treatment for a medical condition of the subject.