BMC Nephrology (Jul 2019)

Urine klotho is a potential early biomarker for acute kidney injury and associated with poor renal outcome after cardiac surgery

  • Yingying Qian,
  • Lin Che,
  • Yucheng Yan,
  • Renhua Lu,
  • Mingli Zhu,
  • Song Xue,
  • Zhaohui Ni,
  • Leyi Gu

DOI
https://doi.org/10.1186/s12882-019-1460-5
Journal volume & issue
Vol. 20, no. 1
pp. 1 – 8

Abstract

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Abstract Background Current paradigms of detecting acute kidney injury (AKI) are insensitive and non-specific. Klotho is a pleiotropic protein that is predominantly expressed in renal tubules. In this study, we evaluated the diagnostic and prognostic roles of urine Klotho for AKI following cardiac surgery. Methods We conducted a prospective study involving 91 patients undergoing cardiac surgery. AKI was defined according to the AKIN definition. The renal outcomes within 7 days after operation were evaluated. Perioperative levels of urine Klotho and urine neutrophil gelatinase-associated lipocalin (NGAL) were measured by using ELISA. Results Of 91 participants, 33 patients (36.26%) developed AKI. Of these AKI patients, 21 (63.64%), 8 (24.24%), and 4 (12.12%) were staged 1, 2, and 3, respectively. Serum creatinine in AKI patients began to slightly increase at first postoperative time and reached the AKI diagnostic value 1 day after operation. Postoperative urine Klotho peaked at the first postoperative time (0 h after admission to the intensive care unit (ICU)) in patients with AKI, and was higher than that in non-AKI patients up to day 3. The AUC of detecting AKI for urine Klotho was higher than urine NGAL at the first postoperative time and 4 h after admission to the ICU. In a multivariate model, increased first postoperative urine Klotho may be an independent predictor for AKI occurrence following cardiac surgery. The concentrations of first postoperative urine Klotho were higher in AKI stage 2 and 3 than those in stage 1 (p < 0.05), and were higher in patients with incomplete recovery of renal function than those with complete recovery (p < 0.05). Conclusions Urine Klotho may serve as an early biomarker for AKI and subsequent poor short-term renal outcome in patients undergoing cardiac surgery.

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