Urinary Vanin-1 in the detection of acute kidney injury in humans

Background Former studies indicate, that urinary Vascular Non-Inflammatory Molecule 1 (Vanin-1) may be an early biomarker of acute tubular necrosis. We evaluated the diagnostic performance of Vanin-1 regarding the detection of acute kidney injury (AKI) and the differentiation of prerenal from intrinsic AKI compared to other known biomarkers. Materials and methods Urinary Vanin-1, Neutrophil gelatinase-associated Lipocalin (NGAL), Kidney injury molecule 1 (KIM-1) and calprotectin concentrations were assessed in 112 hospitalized subjects, 51 with intrinsic and 61 with prerenal AKI. 27 healthy subjects served as controls. Exclusion criteria were postrenal AKI or renal transplantation. Only patients with severe AKI were eligible. Results were expressed as urinary creatinine ratios. Results Median urinary Vanin-1/creatinine was significantly higher in patients with AKI (1912 [812.1–4808] vs. 344.2 [165.2-553.4] pg/mg, p = 0.001; AUROC 0.86 [95% CI 0.80–0.93], p = 0.001). The AUROC for NGAL-, KIM-1- and calprotectin/creatinine were 0.92 (95% CI 0.87–0.97; p = 0.001), 0.96 (95% CI 0.92–0.99; p = 0.001), 0.82 (95% CI 0.74–0.90; p = 0.001), respectively. The diagnostic accuracy of urinary Vanin-1/creatinine in the differentiation of prerenal from intrinsic AKI was low (AUROC 0.64 [95% CI 0.54–0.75, p = 0.01]). The respective AUROCs for NGAL/creatinine, calprotectin/creatinine and KIM-1/creatinine were 0.71 ([95% CI 0.61–0.80], p = 0.001), 0.77 ([95% CI 0.68–0.86], p = 0.001) and 0.54 ([95% CI 0.44–0.65], p = 0.001). Conclusion To our knowledge, this is one of the largest human studies evaluating urinary Vanin-1 in AKI. Urinary Vanin-1/creatinine ratio was higher in patients with AKI compared to controls. However, its diagnostic accuracy in the differentiation of intrinsic from prerenal AKI was lower than of other biomarkers.