Kl. Napoli et al., AN APPROPRIATE STATISTICAL APPROACH FOR THE COMPARISON OF FPIA TO HPLC FOR DETERMINATION OF CYCLOSPORINE CONCENTRATIONS IN ANIMAL-TISSUES, Journal of clinical ligand assay, 19(3), 1996, pp. 190-197
Monoclonal antibody-mediated fluorescence polarization immunoassay (FP
IA) is used with the TDx(R) analyzer to determine cyclosporine (CsA) w
hole blood concentrations in the clinical laboratory. In this study we
compared FPIA with high performance liquid chromatography (HPLC) for
quantitation of CsA in tissue homogenates from rats that had been subj
ected to CsA administration. After FPIA analysis of drug-free tissue h
omogenates spiked with known amounts of CsA showed no significant matr
ix effects, FPIA was used to reevaluate CsA concentrations in homogena
tes of 238 heart, kidney, liver, spleen, lung, muscle and intestinal t
issues that had previously been analyzed by HPLC. As the results of bo
th analytical methods expressed variation in measurement imprecision a
s a function of CsA concentration, a rigorous weighted Deming regressi
on analysis was deemed most appropriate for comparison of the results
of the two methods. This statistical evaluation provided convincing ev
idence that FPIA is a suitable substitute for HPLC for analysis of CsA
concentrations in rat tissues, as the FPIA produced CsA concentration
s that were only marginally different statistically from concentration
s produced by HPLC.