CST3 and acute kidney injury: The findings of a meta-analysis of 30 prospective studies with more than 4000 patients indicate that an increased serum cystatin C is significantly associated with all-cause AKI, with an AUC of 0.89, 82% sensitivity (95% CI 0.75-0.87), 82% specificity (95% CI 0.78-0.86), and a positive likelihood ratio of 4.6 (95% CI 3.6-5.9), making it a reliable marker of AKI (24).