title: A label-free approach by infrared spectroscopic imaging for interrogating the biochemistry of diabetic nephropathy progression.
abstract: Routine histology, the current gold standard, involves staining for specific biomolecules. However, untapped biochemical information in tissue can be gathered using biochemical imaging. Infrared spectroscopy is an emerging modality that allows label-free chemical imaging to derive biochemical information (such as protein, lipids, DNA, collagen) from tissues. Here we employed this technology in order to better predict the development of diabetic nephropathy. Using human primary kidney biopsies or nephrectomies, we obtained tissue from 4 histologically normal kidneys, 4 histologically normal kidneys from diabetic subjects, and 5 kidneys with evidence of diabetic nephropathy. A biochemical signature of diabetic nephropathy was derived that enabled prediction of nephropathy based on the ratio of only 2 spectral frequencies. Nonetheless, using the entire spectrum of biochemical information, we were able to detect renal disease with near-perfect accuracy. Additionally, study of sequential protocol biopsies from 3 transplanted kidneys showed biochemical changes even prior to clinical manifestation of diabetic nephropathy. Thus, infrared imaging can identify critical biochemical alterations that precede morphologic changes, potentially allowing for earlier intervention.
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Vishal K
authors.initials: VK
authors.lastname: Varma
authors.affiliation: Department of Pathology, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Andre
authors.initials: A
authors.lastname: Kajdacsy-Balla
authors.affiliation: Department of Nephrology, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Sanjeev K
authors.initials: SK
authors.lastname: Akkina
authors.affiliation: Department of Pathology, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Suman
authors.initials: S
authors.lastname: Setty
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Pathology, University of Illinois at Chicago, Chicago, Illinois, USA. Electronic address: walshm@uic.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Walsh
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D016022:Case-Control Studies; D003928:Diabetic Nephropathies / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D006801:Humans; D007668:Kidney / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D016030:Kidney Transplantation; D008875:Middle Aged; D011237:Predictive Value of Tests; D012008:Recurrence; D015203:Reproducibility of Results; D013055:Spectrophotometry, Infrared / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers
keywords: biopsy; diabetes; imaging; infrared; pathology; spectroscopy; transplant