Molecular biomarker candidates of acute kidney injury in zero-hour renal transplant needle biopsies.

The aim of this study was to assess gene expression levels of four biomarker candidates [lipocalin 2 (LCN2), the kidney injury molecule 1 (HAVCR1), netrin 1, and the cysteine-rich, angiogenic inducer, 61] in the tubulointerstitial and the glomerular compartment of zero-hour kidney biopsies in order to predict developing delayed graft function (DGF). Thirty-four needle kidney biopsy samples of deceased donors were manually microdissected. Relative gene expression levels were determined by real-time RT-PCR. For the validation of the biomarker candidates, we calculated a mixed model comparing kidneys with DGF, primary function and control samples from the healthy parts of tumor nephrectomies. Significant biomarker candidates were analyzed together with donor age in multivariable regression models to determine the prognostic value. Expression levels of LCN2 and HAVCR1 in the tubulointerstitium were significantly upregulated in the DGF group (LCN2: fold change = 3.78, P = 0.031 and HAVCR1: fold change = 3.44, P = 0.010). Odds ratios of both genes could not reach significance in the multivariable model together with donor age. The area under the curve of the receiver operating characteristic ranges between 0.75 and 0.83. LCN2 and HAVCR1 gene expression levels in zero-hour biopsies show potential to act as early biomarkers for DGF.