We performed a secondary analysis using the multi-national prospective observational SAPPHIRE study to externally validate the ability of the novel biomarker urinary CCL14 to predict persistent severe AKI, defined as at least 72 h of stage 3 AKI, receipt of RRT or death, among a heterogeneous cohort of critically ill patients with stage 2–3 AKI. Here, CCL14 is linked to acute kidney injury.