BACKGROUND Identifying patients with acute kidney injury (AKI) at high risk of chronic kidney disease (CKD) progression remains a challenge.METHODS Kidney transcriptome sequencing was applied to identify the top upregulated genes in mice with AKI. The product of the top-ranking gene was identified in tubular cells and urine in mouse and human AKI. Two cohorts of patients with prehospitalization estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2 who survived over 90 days after AKI were used to derive and validate the predictive models. AKI-CKD progression was defined as eGFR < 60 mL/min/1.73 m2 and with minimum 25% reduction from baseline 90 days after AKI in patients with prehospitalization eGFR ≥ 60 mL/min/1.73 m2. AKI-advanced CKD was defined as eGFR < 30 mL/min/1.73 m2 90 days after AKI in those with prehospitalization eGFR 45–59 mL/min/1.73 m2.RESULTS Kidney cytokeratin 20 (CK20) was upregulated in injured proximal tubular cells and detectable in urine within 7 days after AKI. High concentrations of urinary CK20 (uCK20) were independently associated with the severity of histological AKI and the risk of AKI-CKD progression. In the Test set, the AUC of uCK20 for predicting AKI-CKD was 0.80, outperforming reported biomarkers for predicting AKI. Adding uCK20 to clinical variables improved the ability to predict AKI-CKD progression, with an AUC of 0.90, and improved the risk reclassification.CONCLUSION These findings highlight uCK20 as a useful predictor for AKI-CKD progression and may provide a tool to identify patients at high risk of CKD following AKI.FUNDING National Natural Science Foundation of China, National Key R&D Program of China, 111 Plan, Guangdong Key R&D Program
Rui Ma, Han Ouyang, Shihong Meng, Jun Liu, Jianwei Tian, Nan Jia, Youhua Liu, Xin Xu, Xiaobing Yang, Fan Fan Hou
Upregulation of CK20 protein expression in kidney in severe mouse and human AKI.