title: Detection of endogenous biomolecules in Barrett's esophagus by Fourier transform infrared spectroscopy.
abstract: Fourier transform infrared (FTIR) spectroscopy provides a unique molecular fingerprint of tissue from endogenous sources of light absorption; however, specific molecular components of the overall FTIR signature of precancer have not been characterized. In attenuated total reflectance mode, infrared light penetrates only a few microns of the tissue surface, and the influence of water on the spectra can be minimized, allowing for the analyses of the molecular composition of tissues. Here, spectra were collected from 98 excised specimens of the distal esophagus, including 38 squamous, 38 intestinal metaplasia (Barrett's), and 22 gastric, obtained endoscopically from 32 patients. We show that DNA, protein, glycogen, and glycoprotein comprise the principal sources of infrared absorption in the 950- to 1,800-cm(-1) regime. The concentrations of these biomolecules can be quantified by using a partial least-squares fit and used to classify disease states with high sensitivity, specificity, and accuracy. Moreover, use of FTIR to detect premalignant (dysplastic) mucosa results in a sensitivity, specificity, positive predictive value, and total accuracy of 92%, 80%, 92%, and 89%, respectively, and leads to a better interobserver agreement between two gastrointestinal pathologists for dysplasia (kappa = 0.72) versus histology alone (kappa = 0.52). Here, we demonstrate that the concentration of specific biomolecules can be determined from the FTIR spectra collected in attenuated total reflectance mode and can be used for predicting the underlying histopathology, which will contribute to the early detection and rapid staging of many diseases.
authors: Division of Gastroenterology, Stanford University School of Medicine, Palo Alto Veterans Affairs Health Care System, Palo Alto, CA 94304, USA. thomaswa@umich.edu
authors: Thomas D
authors: TD
authors: Wang
authors: George
authors: G
authors: Triadafilopoulos
authors: James M
authors: JM
authors: Crawford
authors: Lisa R
authors: LR
authors: Dixon
authors: Tarun
authors: T
authors: Bhandari
authors: Peyman
authors: P
authors: Sahbaie
authors: Shai
authors: S
authors: Friedland
authors: Roy
authors: R
authors: Soetikno
authors: Christopher H
authors: CH
authors: Contag
mesh_terms: D001471:Barrett Esophagus / Q000145:classification / Q000473:pathology*; D001706:Biopsy; D002471:Cell Transformation, Neoplastic; D004947:Esophagus / Q000473:pathology; D005753:Gastric Mucosa / Q000473:pathology; D006801:Humans; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods