CST3 and acute kidney injury: In a study using cystatin C as an early marker for AKI, a cutoff cystatin C increase concentration of ≥10% at 24 hours after contrast media exposure was detected in 21.2% of patients and was the best cutoff value for the early identification of patients at risk for CI-AKI with a negative predictive value of 100% and a positive predictive value of 39% [43].