Biomarkers Gauge Kidney Injury After Heart Surgery
(HealthDay News) – Measuring biomarkers found in blood and urine after heart surgery can help predict which patients with acute kidney injury (AKI) will experience AKI progression, according to a study published online March 1 in the Journal of the American Society of Nephrology.
Jay L. Koyner, MD, of the University of Chicago, and colleagues used samples from 380 patients from the Translational Research Investigating Biomarker Endpoints in AKI study to evaluate whether kidney injury biomarkers measured at the time of first clinical diagnosis can predict AKI severity. Biomarkers included urinary interleukin (IL)-18, urinary albumin to creatinine ratio (ACR), and urinary and plasma neutrophil gelatinase-associated lipocalin (NGAL). Each measurement was taken on the day of AKI diagnosis in patients who developed at least AKI Network (AKIN) stage 1 AKI. AKI progression was defined by worsening AKIN stage.
The researchers found that AKI progression occurred in 45 patients (11.8%). After adjusting for other clinical predictors, the highest quintiles of the three biomarkers remained associated with AKI progression compared with biomarker values in the lowest two quintiles: IL-18 (odds ratio [OR], 3), ACR (OR, 3.4), and plasma NGAL (OR, 7.7). Compared with the clinical model alone, each biomarker significantly improved risk classification, with the best performance seen for plasma NGAL (category-free net reclassification improvement of 0.69).
"Biomarkers measured on the day of AKI diagnosis improve risk stratification and identify patients at higher risk for progression of AKI and worse patient outcomes," the authors write.
Several authors disclosed financial ties to pharmaceutical companies and/or are listed as co-inventors on the IL-18 and NGAL patents.