Urinary Kininogen-1 and Retinol binding protein-4 respond to Acute Kidney Injury: predictors of patient prognosis?

Sci Rep. 2016 Jan 21:6:19667. doi: 10.1038/srep19667.


Implementation of therapy for acute kidney injury (AKI) depends on successful prediction of individual patient prognosis. Clinical markers as serum creatinine (sCr) have limitations in sensitivity and early response. The aim of the study was to identify novel molecules in urine which show altered levels in response to AKI and investigate their value as predictors of recovery. Changes in the urinary proteome were here investigated in a cohort of 88 subjects (55 AKI patients and 33 healthy donors) grouped in discovery and validation independent cohorts. Patients' urine was collected at three time points: within the first 48 h after diagnosis(T1), at 7 days of follow-up(T2) and at discharge of Nephrology(T3). Differential gel electrophoresis was performed and data were confirmed by Western blot (WB), liquid chromatography/mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA). Retinol binding protein 4 (RBP4) and kininogen-1 (KNG1) were found significantly altered following AKI. RBP4 increased at T1, and progressively decreased towards normalization. Maintained decrease was observed for KNG1 from T1. Individual patient response along time revealed RBP4 responds to recovery earlier than sCr. In conclusion, KNG1 and RBP4 respond to AKI. By monitoring RBP4, patient's recovery can be anticipated pointing to a role of RBP4 in prognosis evaluation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / diagnosis*
  • Acute Kidney Injury / etiology
  • Acute Kidney Injury / urine*
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers
  • Comorbidity
  • Creatinine / blood
  • Female
  • Humans
  • Kininogens / urine*
  • Male
  • Middle Aged
  • Prognosis
  • ROC Curve
  • Retinol-Binding Proteins, Plasma / urine*
  • Young Adult


  • Biomarkers
  • KNG1 protein, human
  • Kininogens
  • RBP4 protein, human
  • Retinol-Binding Proteins, Plasma
  • Creatinine