Table 2.

The diagnostic capabilities of urinary biomarkers of AKI

AKI Time PointBiomarkerFindings
Before SCr/UOP-defined AKITIMP2*IGFBP7An elevated urinary TIMP2*IGFBP7 >0.3 identifies patients at risk for severe AKI and, when coupled with a guideline-based, renal-protective care bundle, there are lower rates of severe (Stage 2/3) AKI and improved patient outcomes (shorter length of stay and lower cost of care) (7,9,10).
uNGALHigher urinary NGAL (>42/7 ng/ml) on admission was associated with higher AKIN stages of AKI, with sensitivity of 64.5% (95% CI, 53.5% to 74.3%) and specificity of 64.5% (95% CI, 58.8% to 69.8%) (6).
Clinical AKI diagnosisuNGALElevated urine NGAL (>141 ng/ml) measured at the time of AKI diagnosis (SCr increase) was associated with 2.32 increased odds of progressive/worsening AKI compared with those with values <20.1 ng/ml (11).
IL-18Elevated urinary IL-18 (>185 pg/ml) measured at the time of AKI diagnosis was associated with 3.6 increased odds of progressive AKI compared with those with values <29.6 pg/ml (11).
Established AKICCL-14Urinary CCL-14 levels >2.21 ng/ml in patients with stage 2 or 3 AKI after cardiac surgery provided a sensitivity of 78% and specificity of 95% for the development of Stage 2 or 3 AKI that lasted 72 hours of more. CCL-14 values provided an AUC of 0.91 for the receipt of RRT in the next 7 days (13).
  • SCr, serum creatinine; UOP, urine output; TIMP2*IGFBP7, tissue inhibitor of metalloproteinase-2*IGF binding protein 7; uNGAL, urine neutrophil gelatinase associated lipocalin; AKIN, Acute Kidney Injury Network; CCL-14, C-C motif chemokine ligand-14; AUC, area under the curve.