Study on Dynamic Upwarp State Correction Coefficient of Cyclosporine Blood Concentration Determined by EMIT / 中国药房

OBJECTIVE:To explore the dynamic upwarp state correction coefficient of cyclosporine blood concentration determined by EMIT. METHODS:The dynamic upwarp state of cyclosporine concentration was determined by EMIT. The cyclosporine calibration reagents with concentration of 100 ng/mL was used as the sample to be measured,the 58th and 101st test results were selected to simulate the dynamic upwarp state related coefficients,and the 1st,20th,45th,77th,106th,115th test results were corrected by above coefficients. The difference of correction quality concentration with real quality concentration was investigated. RESULTS:The dynamic upwarp state coefficient [k=(1+0.001 235×n0.419 5)n] and dynamic upwarp state correction coefficient {k′=1/[(1+0.001 235×n0.419 5)n} were obtained. After determination results were corrected,relative error of corrected quality concentration with real quality concentration was within ± 4%.CONCLUSIONS:The obtained dynamic upwarp state correction coefficient can be used for dynamic calibration of cyclosporine quality control concentration,which contribute to correct determination of blood concentration of cyclosporine.

Comparative Stndy on Concentration Determination of Valproic Acid in Human Serum by LC-MS/MS and EMIT / 中国药房

OBJECTIVE:To compare the difference in the concentration determination of valproie acid (VPA) in human serum by LC-MS/MS and EMIT.METHODS:Both LC-MS/MS and EMIT methods were applied to determine the serum concentration of VPA in 144 inpatients or outpatients.The paired t-test,Pearson correlation analysis,Bland-Altman deviation chart and other methods were used to evaluate the difference in the results of concentration determination.RESULTS:The results of LC-MS/MS method was pos itively correlated with that of EMIT method (r=0.924,P＜0.05);the regression equation of them was cEMIT=0.920 7cLC.MS/MS-1.114 4 (r=0.924).Average serum concentrations of VPA determined by LC-MS/MS and EMIT were (49.9 ± 21.2) and (54.9 ± 21.3) μg/mL,with statistical significance (P＜0.05).The serum concentration of VPA determined by EMIT was higher than that by LC-MS/MS 8.3 μg/mL,95％ confidence interval was (-13.6,18.7).CONCLUSIONS:The serum concentration of VPA determined by LC-MS/MS and EMIT have high correlation.But the determination results still have certain difference,it is suggested to use same method for long term monitering.

Research on Results of Plasma Mycophenolic Acid Concentration Detected by EMIT and HPLC in the Patients after Renal Transplantation / 现代检验医学杂志

Objective The correlation and agreement of mycophenolic acid (MPA) plasma concentrations that detected by enzyme extended immunoassay (EMIT) and high performance liquid chromatography (HPLC) were studied using Pearson's correlation and Bland-Altman plots.METHODS 435 plasma samples were collected from 95 renal transplant patients who were treated with MPA from October 2014 to December 2015.The MPA plasma concentrations were simultaneously measured by EMIT and HPLC respectively,and the results were divided into two levels.Paired t test and Pearson's correlation were performed using SPSS13.0 to evaluate the relationships between the results in each level.The Bland-Altman plot was used to assess the agreement of the results of two methods.Results Higher concentrations were obtained with EMIT,there was a significant positive bias of EMIT for MPA(20.94％ ±14.42 ％,P＜0.001).Pearson's correlation analysis and Bland-Altman analysis showed that the results from different methods presented good correlation (r＞0.98) and agreement.Conclusion The results of EMIT were higher than that of HPLC.There were good correlation and agreement between the two methods.The differences between EMIT and HPLC suggest that different therapeutic window should be set up when the two methods are used for MPA therapeutic drug monitoring.

Performance Evaluation of the Syva EMIT Methotrexate Assay on the Toshiba 200FR NEO

BACKGROUND: Methotrexate (MTX) is an antifolate antagonist that is widely used for treating various malignancies and non-malignant diseases. MTX levels should be monitored when used in high concentration to determine when to start leucovorin rescue. In this study, we evaluated the analytical performance of the EMIT Methotrexate Assay on a 200FR NEO Chemistry Analyzer (Toshiba Medical System Co., Japan) and compared it with Viva-E Drug Testing System (Siemens Healthcare, Germany). METHODS: According to the Clinical Laboratory and Standards Institute (CLSI) Evaluation Protocol (EP) 5-A2, three concentrations of the Liquichek Therapeutic Drug Monitoring Control (Bio-Rad Laboratories, USA) were analyzed twice a day for 20 days to monitor assay precision. The 200FR NEO and Viva-E instruments were compared using 40 patients' sera, according to CLSI EP9-A2. The linearity and carry-over rate were also evaluated. RESULTS: Between-run CVs for low-, medium-, and high-level controls were 4.9%, 0.9%, and 2.0%, respectively, whereas between-day CVs for low-, medium-, and high-level controls were 8.1%, 1.3%, and 3.5%, respectively. In the linearity test, the coefficient of determination (R2) was 0.98 (0.06-1.92 micromol/L). In the comparison study, R2 was 0.955, showing good correlation between the 200FR NEO and Viva-E instruments. The carry-over rate was 0.9%. CONCLUSIONS: The EMIT assay showed good precision, linearity, and carry-over rate on the Toshiba 200FR. An excellent correlation was observed when comparing results obtained using the Toshiba and Viva-E instruments. In conclusion, the Syva EMIT MTX assay can be readily used for MTX monitoring on the Toshiba 200FR NEO.

Evaluation of Viva-E Drug Testing System / 대한진단검사의학회지

BACKGROUND: The importance and usefulness of therapeutic drug monitoring (TDM) have been emphasized, and analysis of drugs has been increased in clinical laboratories. We evaluated the analytical performance and clinical usefulness of a recently introduced enzyme multiplied immunoassay instrument, Viva-E Drug Testing System (Dade Behring Inc., USA). METHODS: Using patients' samples and quality control material, we evaluated the analytical performance of Viva-E for a total of 11 drugs (cyclosporine, tacrolimus, mycophenolic acid, valproic acid, digoxin, theophylline, carbamazepine, phenytoin, phenobarbital, vancomycin, and gentamicin) with respect to linearity, precision, and correlations with other methods according to CLSI guidelines. Cobas Integra 800 (Roche Diagnostics, Switzerland) and API 4000 LC-MS/MS System (Applied Biosystems, USA) were used to make a comparison. In addition, we analyzed analysis time. RESULTS: Viva-E showed a good linearity (r2 > or = 0.97) for all items. Within-run CVs were within 5% and total CVs were within 10% for all drugs except for tacrolimus and digoxin at low concentrations. The system correlated well with the other methods (r=0.9283-0.9778). The time required for reporting the first sample was 11 min and the analysis time was 1.1 min. CONCLUSIONS: Since Viva-E showed a good analytical performance required for TDM in its linearity, precision, and accuracy with its wide drug menus including cyclosporine, tacrolimus, and mycophenolic acid, stat and random accessing functions, and the consolidation to a single workstation, it could be very useful in the clinical laboratory for various needs.