title: Measurement of plasma cell-free DNA concentrations in dogs with sepsis, trauma, and neoplasia.
abstract: OBJECTIVE
  To determine if cell-free DNA (cfDNA) was identifiable in canine plasma, to evaluate 3 techniques for the measurement of plasma cfDNA concentrations in dogs presented to an emergency service, and to compare the plasma cfDNA concentrations of healthy dogs to those with sepsis, trauma, and neoplasia.
  
  
  METHODS
  Retrospective study of banked canine plasma samples collected between May 2014 and December 2014.
  
  
  METHODS
  Dogs presented to the emergency service of a university veterinary teaching hospital.
  
  
  METHODS
  Plasma cfDNA was measured on residual plasma samples obtained from 15 dogs with sepsis, 15 dogs with moderate-severe trauma, 15 dogs diagnosed with a sarcoma. Plasma cfDNA was also measured in 15 healthy dogs.
  
  
  METHODS
  None.
  
  
  RESULTS
  Assay linearity, repeatability, and reproducibility were evaluated. Quantification of cfDNA was performed in duplicate on diluted citrated plasma and following DNA purification using 2 fluorescence assays (SYBR-Gold; Quant-iT) and by ultraviolet absorbance spectroscopy. Fluorescence intensities (FIs) were converted to cfDNA concentrations using standard curves. Median FI values and cfDNA concentrations were compared to healthy controls using the Kruskal-Wallis test, with adjustment for multiple comparisons. Alpha was set at 0.05. Both assays had excellent linearity, and acceptable repeatability and reproducibility. Compared to controls, plasma cfDNA concentrations were significantly increased in dogs with sepsis or moderate-severe trauma with both assays (P ≤ 0.003). Dogs with neoplasia had significantly increased cfDNA concentrations with the Quant-iT assay only (P = 0.003). When measurements were performed on purified DNA, only dogs with moderate-severe trauma had significantly increased cfDNA concentrations (P < 0.001; SYBR-Gold assay).
  
  
  CONCLUSIONS
  cfDNA can be readily identified in canine plasma using 2 fluorescence assays. DNA extraction offers no advantage over direct measurement. Compared to healthy controls, dogs with sepsis or moderate-severe trauma have significantly increased plasma cfDNA concentrations.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853.
authors.forename: Jo-Annie
authors.initials: JA
authors.lastname: Letendre
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853.
authors.forename: Robert
authors.initials: R
authors.lastname: Goggs
mesh_terms: D000818:Animals; D004247:DNA / Q000097:blood*; D004283:Dog Diseases / Q000097:blood*; D004285:Dogs; D004630:Emergencies / Q000662:veterinary; D005470:Fluorometry / Q000662:veterinary; D009104:Multiple Trauma / Q000097:blood / Q000662:veterinary; D009369:Neoplasms / Q000097:blood / Q000662:veterinary; D010949:Plasma / Q000737:chemistry*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018805:Sepsis / Q000097:blood / Q000662:veterinary*; D013056:Spectrophotometry, Ultraviolet / Q000662:veterinary
chemical_list: D004247:DNA