Morishige H, Shuto H, Ieiri I, Otsubo K, Oishi R
Department of Hospital Pharmacy, Kyushu University, Fukuoka, Japan.
Ther Drug Monit. 1996 Feb;18(1):80-5. doi: 10.1097/00007691-199602000-00013.
Fluorescence polarization immunoassay (FPIA) is widely used to determine serum vancomycin concentrations, and it has been shown to over-estimate vancomycin concentrations in sera from renally impaired patients. This phenomenon has generally been thought to result from interference by vancomycin crystalline degradation products (CDP-1). In this study, we confirmed that serum vancomycin concentrations in various patients determined by FPIA were higher than those determined by high-performance liquid chromatography (HPLC) or enzyme multiplied immunoassay (EMIT). However, the quantitative differences in the serum vancomycin concentrations determined by FPIA versus HPLC were higher than the CDP-1 concentrations, even when the cross-reactivity of FPIA to CDP-1 is assumed to be 100%. When the vancomycin calibrators for FPIA were stored at 4 degrees C for 30 days, their concentrations determined by FPIA and HPLC decreased by 14 and 20%, respectively, and CDP-1 corresponding to 20% of primary vancomycin was formed. When stored at 25 degrees C, the degradation of vancomycin was more marked. We concluded that not only the cross-reactivity of FPIA to CDP-1 but also the instability of calibrators may cause the overestimation of serum vancomycin concentrations determined by FPIA.
荧光偏振免疫分析法（FPIA）被广泛用于测定血清万古霉素浓度，并且已证明它会高估肾功能受损患者血清中的万古霉素浓度。一般认为这种现象是由万古霉素结晶降解产物（CDP - 1）的干扰导致的。在本研究中，我们证实通过FPIA测定的各类患者血清万古霉素浓度高于通过高效液相色谱法（HPLC）或酶放大免疫分析法（EMIT）测定的浓度。然而，即使假设FPIA对CDP - 1的交叉反应率为100%，FPIA与HPLC测定的血清万古霉素浓度的定量差异仍高于CDP - 1的浓度。当FPIA的万古霉素校准品在4℃储存30天时，通过FPIA和HPLC测定的其浓度分别下降了14%和20%，并且形成了相当于初始万古霉素20%的CDP - 1。当在25℃储存时，万古霉素的降解更为明显。我们得出结论，不仅FPIA对CDP - 1的交叉反应率，而且校准品的不稳定性都可能导致FPIA测定的血清万古霉素浓度被高估。
