Clinical significance of tubular and podocyte biomarkers in acute kidney injury

Katsuomi Matsui, Atsuko Kamijo-Ikemori, Masanori Hara, Takeshi Sugaya, Takamitsu Kodama, Sigeki Fujitani, Yasuhiko Taira, Takashi Yasuda, Kenjiro Kimura

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

Background: Acute kidney injury (AKI) is a common complication in critically ill patients. Urinary excretion of liver-type fatty acid-binding protein (L-FABP), which is expressed in the proximal tubules, reflects the presence of tubular injury. Urinary excretion of podocalyxin (PCX), a glycoprotein prominently expressed on podocytes, is associated with podocyte injury. Our aims were to evaluate the utility of urinary L-FABP for the early detection of AKI and to examine whether podocyte injury is present in AKI patients using the biomarker of urinary PCX. Methods: Patients admitted to the intensive care unit (ICU) were divided into the AKI group (n = 14) and non-AKI group (n = 11), according to the occurrence of AKI during hospitalization in the ICU. Changes in various biomarkers were evaluated. Results: In the AKI group, elevation of urinary L-FABP level [maximum value of L-FABP, 199.0 (92.5-433.6) μg/g creatinine, median (25-75% interquartile range)], which reflects tubular injury (area under the curve 0.95, cut-off value 44.1 μg/g Cr), occurred between -30 and 0 h before the occurrence of AKI (i.e., the time at which serum creatinine peaked), and elevation of urinary PCX level [maximum value of PCX, 389.5 (267.0-501.0) μg/g creatinine; upper limit of reference value, 160 μg/g creatinine] occurred during the time of recovery from AKI when serum creatinine levels were decreasing between 34.0 and 72.0 h after the occurrence of AKI. Furthermore, a parameter with the primary large AUC for predicting the onset of AKI was urinary L-FABP. Conclusions: Our study suggests that L-FABP is a useful biomarker for early detection of AKI and that podocyte injury was induced during the recovery phase of AKI.

Original languageEnglish (US)
Pages (from-to)220-225
Number of pages6
JournalClinical and Experimental Nephrology
Volume15
Issue number2
DOIs
StatePublished - Apr 1 2011

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Keywords

  • Acute kidney injury (AKI)
  • Liver-type fatty acid-binding protein (L-FABP)
  • Podocalyxin (PCX)
  • Podocyte injury

ASJC Scopus subject areas

  • Physiology
  • Nephrology
  • Physiology (medical)

Cite this

Matsui, K., Kamijo-Ikemori, A., Hara, M., Sugaya, T., Kodama, T., Fujitani, S., Taira, Y., Yasuda, T., & Kimura, K. (2011). Clinical significance of tubular and podocyte biomarkers in acute kidney injury. Clinical and Experimental Nephrology, 15(2), 220-225. https://doi.org/10.1007/s10157-010-0384-y