化学发光微粒子免疫法和酶放大免疫法检测环孢素A全血浓度的相关性分析

目的 通过化学发光微粒子免疫法（CMIA）和酶放大免疫法（EMIT）检测环孢素A全血浓度,评价2种方法检测结果的准确性和相关性。方法 CMIA和EMIT检测低、中、高3个全血免疫抑制剂质控物,进行准确度和批内、批间精密度分析;已知浓度的环孢素A（49.5,155.2,395.8,500.0,995.0,1 390.1 ng·mL^-1）加入到不含环孢素A全血样本中,检测后计算结果回收率;测定100份环孢素A患者全血样本,测定值用Deming法进行线性回归分析和Bland-Altman法计算偏倚。结果 CMIA低、中、高3个全血免疫抑制剂质控物准确度相对误差分别为5.8%,5.2%,9.1%,其批内和批间的变异系数分别为7.4%,6.9%,8.6%和10.1%,11.3%,8.7%,CMIA回收率分别为91%,95%,103%,102%,102%,104%;EMIT低、中、高3个全血免疫抑制剂质控物的相对误差分别为2.8%,2.3%,4.3%,其批内和批间的变异系数分别11.2%,5.9%,5.7%和11.3%,9.2%,8.3%,EMIT回收率分别为90%,92%,97%,98%,99%,102%;CMIA和EMIT平均差异偏倚21.7 ng·mL^-1（95% CI：-125.1~168.4 ng·mL^-1）,EMIT测定值/CMIA测定值平均为0.951（95% CI：0.56~1.34）,EMIT测定结果平均低于CMIA 5%左右。结论 CMIA和EMIT检测环孢素A全血浓度符合免疫分析精密度的要求,2种方法的检测结果相关性好,临床合理调整用药剂量时应考虑检测方法类型不同造成的影响。     

Pharmacokinetics of valproic acid in volunteers after a single dose study

The pharmacokinetics of valproic acid (VPA) was investigated in six healthy volunteers. This was done by monitoring total and free (unbound) valproic acid levels in the serum, and the amount of one of its metabolites, VPA glucuronide, in the urine as a function of time, after a single dose administration of the parent drug. VPA half-life calculated from the urine data of the metabolite was shorter than the half-life calculated from the blood data. About 15 to 20 per cent of the administered oral dose of VPA was excreted in the urine as VPA glucuronide. The average free fraction of VPA obtained in this study, by using the EMIT technique, ranged from 1.5 to 11.5 per cent with a mean value of 4.9 per cent.     

酶放大免疫分析法与二维高效液相色谱法监测万古霉素血药浓度的比较

万古霉素血药浓度个体差异较大,故临床需监测其血药浓度。本文分别建立酶放大免疫分析法（EMIT）、二维高效液相色谱法（2D-HPLC-UV）测定万古霉素血药浓度,2种方法的线性、准确度和精密度均符合生物样品检定要求。60份静脉滴注万古霉素患者的血浆样品测定结果显示,两种方法无统计学差异,且相关性好,回归方程为Y2D-HPLC-UV=0.9670×XEMIT-0.7029,Bland-Altman分析显示两种方法一致性良好。两种方法均可有效且可靠地监测万古霉素血药浓度,临床上应综合考虑监测目的、实验室条件和人员配置等,选择合适的测定方法。     

三种检测方法测定甲氨蝶呤血药浓度的比较分析

目的比较高效液相色谱法（HPLC）、荧光偏振免疫分析法（FPIA）和酶增强免疫法（EMIT）监测甲氨蝶呤（MTX）血浆药物浓度的相关性。方法收集接受大剂量甲氨蝶呤化疗后的患者的血液样品,分别用HPLC、FPIA和EMIT法进行测定,考察3种测定方法的相关程度。结果多配对样本Friedman检验提示3种方法间差异有显著性,Wilcoxon检验结果提示HPLC法和FPIA法检测结果之间差异无显著性,EMIT法结果与另外两种方法之间差异有显著性。3种检测方法的的回归分析结果为：Y HPLC=1.00X FPIA＋0.015（r=0.978,P〈0.000 1）;Y HPLC=0.94X EMIT-0.079（r=0.956,P〈0.000 1）;Y FPIA=0.95X EMIT-0.089（r=0.927,P〈0.000 1）。结论 3种甲氨蝶呤检测方法之间还是存在差异,但这种差异是可以预见性的,且可以通过换算消除,临床治疗和研究工作要予以注意。     

The screening for common drugs of abuse in whole blood by means of EMIT-ETS and FPIA-ADx urine immunoassays

Summary The purpose of the paper was to compare the performance of ETS (EMIT) and ADx (FPIA) analyzers for screening blood samples for drugs of abuse after 2 alternative pretreatment procedures (acetone precipitation and ultrafiltration). Cannabinoids, benzodiazepines and benzoylecgonine were not detectable with both assays after ultrafiltration. The detectability of morphine in blood ultrafiltrates was distinctly lower than after acetone precipitation. The comparison of results obtained with ETS and ADx after acetone precipitation showed that ETS assay is slightly more sensitive but AD is slightly more reproducible. Both assays may be used for blood examination with similar cut-off values. The ETS analyzer gave much better analytical performance (speed, flexibility) and lower reagent costs than the ADx analyzer.      

False Positive Acetaminophen Levels Associated with Hyperbilirubinemia

Serum acetaminophen determination is frequently necessary in patients with hepatic failure. We observed two patients (#1, #2) with elevated serum total bilirubin levels (26.5 mg/dL and 40.1 mg/dL) who had multiple false positive acetaminophen levels using the kinetic method of the GDS Diagnostics enzymatic acetaminophen assay (GDS Diagnostics, Elkhart, IN). We investigated the magnitude, threshold, and linearity of this effect using the GDS Diagnostics assay and an EMIT acetaminophen assay on two other hyperbilirubinemic patients (#3, #4) and a commercial solubilized bilirubin standard. Samples were diluted using fresh frozen plasma, and acetaminophen levels were analyzed twice using the kinetic method of the GDS Diagnostic acetaminophen assay and twice with the EMIT assay. The absence of acetaminophen in all samples was verified by gas chromatography/mass spectroscopy (GC/MS). The kinetic GDS assay resulted in a positive acetaminophen assay (cutoff for a positive result = 10 mg/L) with patient #3, patient #4, and in the bilirubin standard when the total bilirubin levels were 28.2 mg/dL, 22.5 mg/dL, and 18.3 mg/dL, respectively. One sample was interpolated to give a positive acetaminophen reading when diluted to a total bilirubin concentration of 15 mg/L. None of the samples tested with GC/MS or the EMIT assay resulted in any detectable acetaminophen. In conclusion, caution must be taken utilizing the GDS Diagnostic assay for the quantification of acetaminophen with concomitant hyperbilirubinemia. Alternatives such as EMIT or GC/MS should be employed to assess acetaminophen levels in such patients.     

他克莫司血药浓度监测的质控方法比较

目的 评价酶增强免疫分析法(enzyme-multiplied immunoassay technique,EMIT)监测患者全血中他克莫司浓度的质量,建立他克莫司血药浓度监测的质量控制方法,提高血药浓度监测的准确性。方法 对本实验室2013年6月—2014年7月的他克莫司血药浓度监测的随行质控结果进行回顾性评价与分析,建立常规中心线及控制限,并分析他克莫司血药浓度低、中、高质控品共计127个点,其中低浓度36点、中浓度52点、高浓度39点。结果 他克莫司低、中、高3水平的常规中心线分别为5.21,9.20,19.34 ng·mL^-1;CV分别为31.01%,22.84%,15.11%。Levey-jennings质控方法检出结果失控1次,Westgard多规则控制方法检出6次失控。结论 Westgard多规则控制方法有较高的误差检出率,优于以作为失控限的Levey-jennings质控方法,使用Westgard多规则控制方法来判断质控结果,提高了监测数据的可靠性,可以为临床提供准确的血药浓度监测结果。     

Detectability of new psychoactive substances, ‘legal highs’, in CEDIA,EMIT, and KIMS immunochemical screening assays for drugs of abuse

The increasing number of new psychoactive substances made available for recreational drug use has created a challenge for clinical toxicology and drug testing laboratories. As a consequence, the routine immunoassay drug testing may become less effective due to an increased occurrence of false negative and false positive screening results. This work aimed to extend the knowledge about analytical cross‐reactivity of new substances in selected CEDIA, EMIT, and KIMS immunoassays for drugs‐of‐abuse screening. Urine standards were prepared by spiking blank urine with 45 new substances. Authentic urine samples from intoxication cases identified by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) were also studied. Several new psychoactive substances were demonstrated to display cross‐reactivity in the immunoassays. CEDIA Amphetamine/Ecstasy and EMIT d.a.u. Amphetamine Class tests showed the highest reactivity towards the new drugs, which was expected since many have amphetamine‐like structure and activity. In the samples from authentic cases, five new substances displayed 100% detection rate in the CEDIA Amphetamine/Ecstasy test. In conclusion, cross‐reactivity data in routine urine drug screening immunoassays for a number of new psychoactive substances not studied before were reported. In both spiked and authentic urine samples, some new substances showed significant cross‐reactivity and are thus detectable in the routine screening methods. Copyright © 2014 John Wiley & Sons, Ltd.