We evaluated ARCHITECT®･iCarbamazepine using chemiluminescent immunoassay (CLIA) with carbamazepine (CBZ) concentration in the serum of patients with epilepsy. The intra- and inter-assay coefficients of variation were 0.87-1.34% and 2.20-6.06%, respectively. Cross-reactivity of CBZ analogs by CLIA varied from 7.00-9.26% with carbamazepine-10,11-epoxide lower than that evaluated by fluorescence polarization immunoassay (FPIA), and 2.09-2.51% with 10-monohydroxycarbazepine higher than that evaluated by FPIA. Oxcarbazepine was not detected. In addition, we observed a correlation between the values obtained by CLIA method and the high performance liquid chromatography (HPLC) method (y = 1.07x - 0.09, r = 0.98), and FPIA method and HPLC method (y = 0.95x - 0.22, r = 0.97). Our results suggest that ARCHITECT®･iCarbamazepine measured the CBZ concentration in serum lower than that measured by FPIA. However we conclude that ARCHITECT®･iCarbamazepine can be used for routine monitoring of CBZ for the reason that ARCHITECT®･iCarbamazepine showed low cross-reactivity with CBZE by classification of CBZE/CBZ ratio.
