Comparison of high performance liquid chromatography and immunoassay methods for measurement of cyclosporine A blood concentrations after feline kidney transplantation.
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.
McAnulty
J F
JF
Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
Lensmeyer
G L
GL
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
D007166:Immunosuppressive Agents; D016572:Cyclosporine