title: Development and analytic validation of a radioimmunoassay for the quantification of canine calprotectin in serum and feces from dogs.
abstract: OBJECTIVE
  To develop and analytically validate a radioimmunoassay (RIA) for the quantification of canine calprotectin (cCP) in serum and fecal extracts of dogs. Sample Population-Serum samples (n = 50) and fecal samples (30) were obtained from healthy dogs of various breeds and ages.
  
  
  METHODS
  A competitive, liquid-phase, double-antibody RIA was developed and analytically validated by assessing analytic sensitivity, working range, linearity, accuracy, precision, and reproducibility. Reference intervals for serum and fecal cCP concentrations were determined.
  
  
  RESULTS
  Sensitivity and upper limit of the working range were 29 and 12,774 microg/L for serum and 2.9 and 1,277.4 microg/g for fecal extracts, respectively. Observed-to-expected ratios for serial dilutions of 6 serum samples and 6 fecal extracts ranged from 95.3% to 138.2% and from 80.9% to 118.1%, respectively. Observed-to-expected ratios for spiking recovery for 6 serum samples and 6 fecal extracts ranged from 84.6% to 121.5% and from 80.3% to 132.1%, respectively. Coefficients of variation for intra-assay and interassay variability were < 3.9% and < 8.7% for 6 serum samples and < 8.5% and < 12.6% for 6 fecal extracts, respectively. Reference intervals were 92 to 1,121 microg of cCP/L for serum and < 2.9 to 137.5 microg of cCP/g for fecal extracts.
  
  
  CONCLUSIONS
  The RIA described here was analytically sensitive, linear, accurate, precise, and reproducible for the quantification of cCP in serum and fecal extracts. This assay should facilitate research into the clinical use of serum and fecal cCP measurements in dogs with inflammatory bowel disease.
authors.affiliation: Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4474, USA.
authors.forename: Romy M
authors.initials: RM
authors.lastname: Heilmann
authors.forename: Jan S
authors.initials: JS
authors.lastname: Suchodolski
authors.forename: Jörg M
authors.initials: JM
authors.lastname: Steiner
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D005243:Feces / Q000737:chemistry*; D015212:Inflammatory Bowel Diseases / Q000378:metabolism / Q000662:veterinary*; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis* / Q000097:blood; D011863:Radioimmunoassay / Q000379:methods / Q000662:veterinary*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D039841:Leukocyte L1 Antigen Complex