title: Analytical evaluation of TDx cyclosporine and metabolites fluorescence polarization immunoassay and comparison with the Cyclo-Trac RIA kit.
abstract: The fluorescence polarization immunoassay (FPIA) developed by Abbott Laboratories (TDx system) for the determination of cyclosporine in plasma was evaluated using whole blood as the analytical sample. The coefficients of variation for the within-run and between-run precision ranged from 3.7 to 5.7% and from 5.5 to 7.3%, respectively, for cyclosporine controls ranging in concentration from 200 to 1500 ng/ml. The detection limit was seen to be 26 ng/ml. We used specimens from renal transplant patients who received cyclosporine to compare the TDx assay with the RIA method (Incstar Cyclo-Trac). There was a good correlation between FPIA and RA results (r = 0.91; TDx = 1.29 RIA + 39.13; n = 88). It was concluded that the FPIA is an acceptable and rapid method for patient cyclosporine analysis in whole blood samples. In therapeutic drug monitoring this method offers advantages over the RIA procedure.
authors.affiliation: Service of Pharmacy, Clinical Hospital, University of Salamanca, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Montojo
authors.forename: M V
authors.initials: MV
authors.lastname: Calvo
authors.forename: A
authors.initials: A
authors.lastname: Domínguez-Gil
mesh_terms: D003524:Cyclosporins / Q000097:blood*; D005069:Evaluation Studies as Topic; D005454:Fluorescence Polarization / Q000379:methods; D005455:Fluorescent Antibody Technique; D006801:Humans; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D003524:Cyclosporins