Growth differentiation factor-15 (GDF15), leucine-rich alpha-2-glycoprotein 1 (LRG1), and secreted phosphoprotein 1 (SPP1/ osteopontin, OPN) were identified as potential candidate markers by proteomic analysis and were validated by ELISA in another 30 patients and in a CP-induced AKI mouse model.
OPN levels were positively correlated to plasma creatinine (r = 0.401 with <i>p</i> = 0.0001), but this relation was not explained by the development of acute kidney injury (AKI), since no difference was found in OPN concentration between AKI and non-AKI patients.
Six predictors were present in the final model: four (history of diabetes, blood urea nitrogen to creatinine ratio, C-reactive protein, and osteopontin) had a positive association with AKI risk, while two (CD5 antigen-like and Factor VII) had a negative association with AKI risk.
Six other urine biomarkers urine albumin, urine beta2-microglobulin, urine kidney injury molecule-1, urine cystatin C, urine trefoil factor-3 and urine osteopontin either had minimal elevation, and/or minimal prediction for AKI stage 2/3 (AUC-ROC<0.7).