title: Multi-excitation fluorescence spectroscopy for analysis of non-alcoholic fatty liver disease.
abstract: OBJECTIVE
  The increasing incidence of non-alcoholic fatty liver diseases (NAFLD) and the consequent progression to cirrhosis is expected to become a major cause of liver transplantation. This will exacerbate the organ donor shortage and mean that 'marginal' fatty liver grafts are more frequently used. Autofluorescence spectroscopy is a fast, objective, and non-destructive method to detect change in the endogenous fluorophores distribution and could prove to be a valuable tool for NAFLD diagnosis and transplant graft assessment.
  
  
  METHODS
  A system was constructed consisting of a fibre probe with two laser diodes that provided excitation light at 375 and 405 nm, and an imaging spectrograph system. This was used to distinguish fluorescence spectra acquired from the harvested livers from mice with NAFLD of differing severity (healthy, mild steatotic and steatohepatitic). The fluorescence data were entered into a sparse multiclass probabilistic algorithm for disease classification. Histopathology, thiobarbituric acid reactive substances (TBARS) and alanine transaminase (ALT) assays were conducted in addition to the fluorescence measurements
  
  
  RESULTS
  TBARS and ALT assays enabled differentiation of the steatohepatitic group from the mild steatosis and control groups (P ≤ 0.028) but failed to separate the mild steatotic group from the control group. The three groups were all clearly differentiated from each other using fluorescence spectroscopy, and classification accuracy was found to be 95%.
  
  
  CONCLUSIONS
  Fluorescence spectroscopy appears to be a promising approach for the analysis of diseased liver tissue.
authors.affiliation: Department of Surgery and Cancer, Imperial College London, London SW72AZ, United Kingdom.
authors.forename: Vincent R
authors.initials: VR
authors.lastname: Sauvage
authors.forename: Adam P
authors.initials: AP
authors.lastname: Levene
authors.forename: Hoa T
authors.initials: HT
authors.lastname: Nguyen
authors.forename: Tobias C
authors.initials: TC
authors.lastname: Wood
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kudo
authors.forename: Danilo
authors.initials: D
authors.lastname: Concas
authors.forename: Howard C
authors.initials: HC
authors.lastname: Thomas
authors.forename: Mark R
authors.initials: MR
authors.lastname: Thursz
authors.forename: Robert D
authors.initials: RD
authors.lastname: Goldin
authors.forename: Quentin M
authors.initials: QM
authors.lastname: Anstee
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Elson
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D005234:Fatty Liver / Q000175:diagnosis* / Q000473:pathology; D054023:Lasers, Semiconductor; D008099:Liver / Q000473:pathology; D016015:Logistic Models; D008297:Male; D051379:Mice; D065626:Non-alcoholic Fatty Liver Disease; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
chemical_list: D017392:Thiobarbituric Acid Reactive Substances; D000410:Alanine Transaminase