Using proteomics to identify preprocedural risk factors for contrast induced nephropathy

Abstract

Contrast induced nephropathy (CIN) is the third leading cause of hospital acquired acute kidney injury (AKI). We conducted a cross‐sectional study in children undergoing elective cardiac catheterization to determine if there is a distinct preprocedural urinary proteomic profile in subjects who subsequently develop CIN. Of 90 patients enrolled, AKI due to CIN (defined as a 50% or greater increase in serum creatinine) occurred in 10 participants by the 24 h postcontrast time point. Seven patients who did not develop AKI served as age and gender matched controls. SELDI‐TOF‐MS was performed using ProteinChips with different chromatographic surfaces. A 4480 Da biomarker displayed significantly greater peak intensities on three chromatographic surfaces (p = 0.02–0.001) in control patients at time = 0 with an area under the curve (AUC) of 0.89–0.99. This biomarker was identified as the 41 amino acid (a.a.) variant of human beta‐defensin‐1. Another biomarker of 4631 Da was found to have a significantly greater peak intensity (p = 0.03) in AKI patients at time = 0, with an AUC of 0.84. Thus, the presence of a 4631 Da peptide, as well as the absence of the 41 a.a. variant of human beta‐defensin‐1 in the preprocedural urine, may prove to be useful biomarkers for the early prediction of CIN.