Aim: Cisplatin causes acute kidney injury (AKI) in approximately one-third of patients. Serum creatinine and urinary output are poor markers of cisplatin-induced (AKI). Metabolomics was utilized to identify predictive or early diagnostic biomarkers of cisplatin-induced AKI. Methods: Thirty-one adult head and neck cancer patients receiving cisplatin (dose ≥ 70 mg m2 -1) were recruited for metabolomics analysis. Urine and serum samples were collected prior to cisplatin (pre), 24-48 hours after cisplatin (24-48h), and 5-14 days (post) after cisplatin. Based on serum creatinine concentrations measured at the post timepoint, 11/31 patients were classified with clinical AKI. Untargeted metabolomics was performed using liquid chromatography-mass spectrometry. Results: Metabolic discrimination was observed between “AKI” patients and “no AKI” patients at all timepoints. Urinary glycine, hippuric acid sulfate, 3-hydroxydecanedioc acid, and suberate were significantly different between AKI patients and no AKI patients prior to cisplatin infusion. Urinary glycine and hippuric acid sulfate were lower (-2.22-fold and -8.85-fold), whereas 3-hydroxydecanedioc acid and suberate were higher (3.62-fold and 1.91-fold) in AKI patients relative to no AKI patients. Several urine and serum metabolites were found to be altered 24-48 hours following cisplatin infusion, particularly metabolites involved with mitochondrial energetics. Conclusion: We propose glycine, hippuric acid sulfate, 3-hydroxydecanedioc acid, and suberate as predictive biomarkers of predisposition to cisplatin-induced AKI. Metabolites indicative of mitochondrial dysfunction may serve as early markers of subclinical AKI.

Background and Purpose: Cisplatin-induced nephrotoxicity manifests as acute kidney injury (AKI) in approximately one third of patients receiving cisplatin therapy. Current measures of AKI are inadequate in detecting AKI prior to significant renal injury, and better biomarkers are needed for early diagnosis of cisplatin-induced AKI. Experimental Approach: C57BL/6 and FVB/N mice were treated with a single intraperitoneal injection of cisplatin (15 mg kg-1) or saline. Plasma, urine, and kidney samples were collected prior to cisplatin injection and 24-, 48-, 72-, and 96-hours following cisplatin injection. Untargeted metabolomics was employed using liquid chromatography-mass spectrometry to identify early diagnostic biomarkers for cisplatin-induced AKI. Key Results: There was clear metabolic discrimination between saline and cisplatin-treated mice at all timepoints (day 1 to day 4). In total, 26 plasma, urine, and kidney metabolites were identified as exhibiting early alterations following cisplatin treatment. Several of the metabolites showing early alterations were associated with mitochondrial function and energetics, including intermediates of the tricarboxylic acid cycle, regulators of mitochondrial function and indicators of fatty acid β-oxidation dysfunction. Furthermore, several metabolites were derived from the gut microbiome. Conclusion and Implications: Our results highlight the detrimental effects of cisplatin on mitochondrial function and demonstrate potential involvement of the gut microbiome in the pathophysiology of cisplatin-induced AKI. Here we provide a panel of metabolites to guide future clinical studies of cisplatin-induced AKI and provide insight into potential mechanisms behind cisplatin nephrotoxicity.