title: Comparison of high performance liquid chromatography and immunoassay methods for measurement of cyclosporine A blood concentrations after feline kidney transplantation.
abstract: OBJECTIVE
  To compare two methods of whole blood cyclosporine A (CsA) measurement in cats.
  
  
  METHODS
  Whole blood samples were analyzed for CsA concentrations with use of high performance liquid chromatography (HPLC) and monoclonal immunoassay methods.
  
  
  METHODS
  Blood (n = 36 samples) was obtained from six cats after renal transplantation.
  
  
  METHODS
  Results were compared by linear regression analysis using both pooled and individual patient data. Eight samples were off-scale on the immunoassay and were excluded.
  
  
  RESULTS
  There was significant correlation between CsA measured using HPLC and immunoassay methods (P < .001; r = .942; r2 = .887). However, individuals varied nonrandomly from the mean pooled patient data. Correlation between the assay methods was higher for individual patients using data only from that specific individual (mean r value = .976; r2 = .955). Clinical utility of the immunoassay (ie, results would prompt an appropriate CsA dosage adjustment) was good when based on individually derived conversion factors (27 of 28 [96.5%] of decision events).
  
  
  CONCLUSIONS
  HPLC is superior for measurement of blood CsA concentrations in cats after kidney transplantation. However, an immunoassay may provide reliable information for CsA management if a comparative database (HPLC v immunoassay) has been previously determined in a specific patient.
  
  
  CONCLUSIONS
  Locally available monitoring of CsA by immunoassay in cats may provide significant advantages when shipping of blood samples to distant locations is required to obtain analysis by HPLC. These advantages may include cost and timeliness of results in circumstances where daily blood CsA concentrations may be desired, such as when managing an acute rejection reaction.
authors.affiliation: Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: McAnulty
authors.forename: G L
authors.initials: GL
authors.lastname: Lensmeyer
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000601:surgery; D002415:Cats / Q000097:blood / Q000601:surgery*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D016572:Cyclosporine / Q000097:blood*; D007118:Immunoassay / Q000662:veterinary; D007166:Immunosuppressive Agents / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000601:surgery / Q000662:veterinary; D016030:Kidney Transplantation / Q000662:veterinary*; D016014:Linear Models
chemical_list: D007166:Immunosuppressive Agents; D016572:Cyclosporine