Tubular Atrophy and Low Netrin-1 Gene Expression Are Associated With Delayed Kidney Allograft Function

Background Delayed graft function (DGF) caused by ischemia/reperfusion injury (I/RI) negatively influences the outcome of kidney transplantation. This prospective single-center study characterized the intrarenal transcriptome during I/RI as a means of identifying genes associated with DGF development. Methods Characterization of the intrarenal transcription profile associated with I/RI was carried out on three sequential graft biopsies from respective allografts before and during transplantation. The intragraft expression of 92 candidate genes was measured using quantitative real-time reverse transcriptase polymerase chain reaction (2(-Ct)) in delayed (n=9) and primary function allografts (n=26). Results Cold storage was not associated with significant changes to the expression profile of the target gene transcripts; however, up-regulation of 16 genes associated with enhanced activation of innate and adaptive immune responses and apoptosis was observed after reperfusion. Multivariate logistic regression analysis revealed that higher tubular atrophy scores (ct) together with a lower expression of Netrin-1 might predict DGF development (training area under the receiver operating curve=0.89, cross-validated area under the receiver operating curve=0.81). Conclusions Poor baseline tubular cell quality (defined by a higher rate of tubular atrophy) combined with the reduced potential of apoptotic survival factors represented by decreased Netrin-1 gene expression were associated with delayed kidney graft function.