These demonstrate good performance across all age groups, with an area under the curve (AUC) value of 0.79 (95% CI: 0.64–0.94, CHIT1), 0.73 (95% CI: 0.6–0.87, CA3) and 0.73 (95% CI: 0.6–0.86, TPM4) for three individual proteins with high abundance in AKI patients and an AUC of 0.72 (95% CI: 0.56–8.87, YIPF3), 0.76 (95% CI: 0.64–0.89, KLK1) and 0.76 (95% CI: 0.62–0.89, CHMP5), respectively, for proteins with low abundance in AKI patients. Here, KLK1 is linked to acute kidney injury.