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Chandras A, Mendu DR, Kirchhoff DC. Effect of Extraction Procedure Substitution on Automated Tacrolimus, Sirolimus, and Cyclosporine Assays. J Appl Lab Med 2024; 9:573-578. [PMID: 38300648 DOI: 10.1093/jalm/jfad128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 10/30/2023] [Indexed: 02/02/2024]
Abstract
BACKGROUND An erroneously high tacrolimus level was reported to a clinician. A root cause analysis investigation failed to determine the cause of the error. It was suspected that the incorrect preanalytical extraction reagent and procedure was used during testing; however, how this would affect the assayed drug concentration was unclear. Here we investigated the effect of the substitution of sirolimus, tacrolimus, and cyclosporine extraction reagents on assayed drug concentration. METHODS Tacrolimus, sirolimus, and cyclosporine concentration were measured on the Abbott Architect i2000 analyzer. Each assay requires a preanalytical extraction step, with a distinct reagent. We investigated the effect of the substitution of the extraction reagents and procedure between the 3 assays on the measured drug concentration. Two experiments were performed, one on samples of known drug concentration and one on samples with no drug present. RESULTS Substituting cyclosporine and sirolimus extraction procedures increased assayed tacrolimus concentrations from 5.6 to 8.47 (+51.25%) and 8.13 (+45.18%) ng/mL, respectively. Extraction procedure substitutions decreased assayed sirolimus from 13.63 to 4.60 (-66.25%) and 8.07 (-40.79%) ng/mL for cyclosporine and tacrolimus. Cyclosporine concentration increased from 274.60 to 391.30 (+42.50%) ng/mL using sirolimus extraction reagents and to 757.30 (+175.78%) ng/mL using tacrolimus extraction reagents. Cross-reactivity was observed between the tacrolimus assay and sirolimus and cyclosporine extraction reagents. CONCLUSIONS Significant changes, both positive and negative, are observed in assayed drug concentration when incorrect extraction procedures are used in the Abbott i2000 tacrolimus, sirolimus, and cyclosporine assays. Preanalytic extraction procedures should be investigated when performing root cause analysis for erroneous therapeutic drug values.
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Affiliation(s)
- Athanasia Chandras
- Department of Pathology, Molecular & Cell Based Medicine, Mount Sinai Hospital, New York, NY, United States
| | - Damodara R Mendu
- Department of Pathology, Molecular & Cell Based Medicine, Mount Sinai Hospital, New York, NY, United States
| | - Daniel C Kirchhoff
- Department of Pathology, Molecular & Cell Based Medicine, Mount Sinai Hospital, New York, NY, United States
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Budelier MM, Hubbard JA. The regulatory landscape of laboratory developed tests: Past, present, and a perspective on the future. J Mass Spectrom Adv Clin Lab 2023; 28:67-69. [PMID: 36880010 PMCID: PMC9985058 DOI: 10.1016/j.jmsacl.2023.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/18/2023] [Accepted: 02/19/2023] [Indexed: 02/25/2023] Open
Affiliation(s)
- Melissa M Budelier
- TriCore Reference Laboratories, Albuquerque, NM, United States.,Department of Pathology, University of New Mexico, Albuquerque, NM, United States
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Brito D, Leogrande P, de la Torre X, Botrè F. Optimization of a method to detect levothyroxine and related compounds in serum and urine by liquid chromatography coupled to triple quadrupole mass spectrometry. J Pharmacol Toxicol Methods 2022; 115:107169. [DOI: 10.1016/j.vascn.2022.107169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/15/2022] [Accepted: 03/23/2022] [Indexed: 11/29/2022]
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Llop S, Murcia M, Alvarez-Pedrerol M, Grimalt JO, Santa-Marina L, Julvez J, Goñi-Irigoyen F, Espada M, Ballester F, Rebagliato M, Lopez-Espinosa MJ. Association between exposure to organochlorine compounds and maternal thyroid status: Role of the iodothyronine deiodinase 1 gene. ENVIRONMENT INTERNATIONAL 2017; 104:83-90. [PMID: 28395858 DOI: 10.1016/j.envint.2016.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 12/09/2016] [Accepted: 12/09/2016] [Indexed: 06/07/2023]
Abstract
INTRODUCTION Exposure to organochlorine compounds (OCs) may interfere with thyroid hormone (TH) homeostasis. The disruption of the deiodinase (DIO) enzymes has been proposed as a mechanism of action. AIM To evaluate the association between exposure to OCs and TH status in pregnant women, as well as to explore the role of genetic variations in the DIO1 and DIO2 genes. METHODS The study population (n=1128) was composed of pregnant women who participated in the INMA Project (Spain, 2003-2006). Hexachlorobenzene (HCB), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4´-DDE), b-hexachlorocyclohexane (b-HCH), polychlorobiphenyl (PCB) congeners 138, 153 and 180, thyroid stimulating hormone (TSH), total triiodothyronine (TT3) and free thyroxine (FT4) were measured in serum samples taken during the first trimester of pregnancy (mean [standard deviation (SD)]: 13.5 [2] weeks of gestation). Polymorphisms in DIO1 (rs2235544) and DIO2 (rs12885300) were genotyped in maternal DNA. Sociodemographic and dietary characteristics were obtained by questionnaire. RESULTS A 2-fold increase in HCB was associated with lower TT3 (% change=-1.48; 95%CI: -2.36, -0.60). Women in the third tertile for b-HCH had lower TT3 (% change=-3.19; 95%CI: -5.64, -0.67). The interactions between DIO1 rs2235544 and PCB153 and b-HCH were statistically significant. The inverse association between PCB153 and TT3 was the strongest among women with AA genotype. Women with CC genotype presented the strongest inverse association between b-HCH and FT4. CONCLUSION Exposure to HCB and b-HCH was associated to a disruption in maternal TT3. The DIO1 rs2235544 SNP modified the association between exposure to some of the OCs (specifically b-HCH and PCB153) and maternal thyroid hormone levels. These results strengthen the hypothesis that DIO enzymes play a role in explaining the disruption of thyroid hormones in relation to exposure to OCs.
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Affiliation(s)
- Sabrina Llop
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
| | - Mario Murcia
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Mar Alvarez-Pedrerol
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Institut Municipal d'Investigació Mèdica (IMIM)-Hospital del Mar, Barcelona, Spain
| | - Joan O Grimalt
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain
| | - Loreto Santa-Marina
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Biodonostia, Instituto de Investigación Biomédica, San Sebastián, Spain; Departamento de Sanidad Gobierno Vasco, Subdirección de Salud Pública de Gipuzkoa, San Sebastián, Spain
| | - Jordi Julvez
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Institut Municipal d'Investigació Mèdica (IMIM)-Hospital del Mar, Barcelona, Spain
| | - Fernando Goñi-Irigoyen
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Biodonostia, Instituto de Investigación Biomédica, San Sebastián, Spain; Public Health Laboratory, Basque Government, San Sebastian, Spain
| | | | - Ferran Ballester
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Marisa Rebagliato
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Department of Medicine, Universitat Jaume I, Castelló de la Plana, Spain
| | - Maria-Jose Lopez-Espinosa
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain
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Barakauskas VE, Bradshaw TA, Smith LD, Lehman CM, Johnson-Davis KL. Process Optimization to Improve Immunosuppressant Drug Testing Turnaround Time. Am J Clin Pathol 2016; 146:182-90. [PMID: 27453440 DOI: 10.1093/ajcp/aqw087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Timely reporting of immunosuppressant (ISP) drug level results is needed for transplant patient management. This study characterized the local ISP testing process, identified bottlenecks and implemented process improvements to meet turnaround time requirements. METHODS Laboratory information time stamps, direct observation and discussion with staff were used to construct a value stream map of the ISP testing process to identify process bottlenecks. Improvements were implemented to attain the required turnaround time. RESULTS Baseline performance of the existing ISP process (seven weeks, n = 272 samples) indicated that only 28% of samples were reported by 2:00 pm Major bottlenecks were identified to be the analytical run schedule, instrument delays, difficulty identifying ISP samples at intake, and difficulty collecting specimens. Process changes resulted in a median of 76% samples reported by 2:00 pm CONCLUSIONS : Adjusting ISP collection and analysis processes improved the laboratory's ability to meet physician requested result reporting time of 2:00 pm.
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Affiliation(s)
- Vilte E Barakauskas
- From the Department of Pathology and Laboratory Medicine, Children's and Women's Health Centre of British Columbia, Vancouver, Canada Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
| | | | - Lonnie D Smith
- University of Utah Health Care, Pharmacy Transplant Services, Salt Lake City
| | - Christopher M Lehman
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City
| | - Kamisha L Johnson-Davis
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT.
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Assuring the Proper Analytical Performance of Measurement Procedures for Immunosuppressive Drug Concentrations in Clinical Practice. Ther Drug Monit 2016; 38:170-89. [DOI: 10.1097/ftd.0000000000000269] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Iyengar A, Kamath N, Phadke KD, Bitzan M. Cyclosporine/ketoconazole reduces treatment costs for nephrotic syndrome. Indian J Nephrol 2013; 23:419-23. [PMID: 24339519 PMCID: PMC3841509 DOI: 10.4103/0971-4065.120338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cyclosporine A (CyA) is an effective agent for the treatment of glucocorticoid-dependent idiopathic nephrotic syndrome (GCDNS), but costs are prohibitive in resource-poor societies. The objectives of this study were to evaluate the efficacy and safety of reducing the dose of CyA by co-administering ketoconazole. A prospective study targeting children 2-18 years of age with GCDNS in remission with CyA monotherapy was conducted. CyA dose was reduced by 50% and ketoconazole was added at 25% of the recommended therapeutic dose, and the drug levels and therapeutic and adverse effects (AE) were monitored. Continued combined therapy after completion of the 4-week trial period was offered. Ten patients (median age 9.5 years, range 3.0-16.0 years) were enrolled in the study. At week 4, the CyA dose was 2.2 ± 0.7 mg/kg/day compared with 5.6 ± 0.9 mg/kg/day at enrolment (P < 0.0001). No AE were noted. All patients continued ketoconazole treatment for at least 3 months. CyA drug cost savings were 61%, and approximately 60% with ketoconazole cost included. The combination of an expensive immunosuppressive drug with a cheap metabolic inhibitor reduced the treatment costs by> 50% without increased adverse events or drug monitoring needs. This intervention demonstrates how access of patients with limited resources to needed drugs can be improved by interference with physiological drug elimination.
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Affiliation(s)
- A Iyengar
- Division of Pediatric Nephrology, St John's Medical College Hospital, Bangalore, India
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Ultra high performance liquid chromatography–tandem mass spectrometry method for cyclosporine a quantification in biological samples and lipid nanosystems. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 927:164-72. [DOI: 10.1016/j.jchromb.2013.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/25/2013] [Accepted: 02/01/2013] [Indexed: 11/20/2022]
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Cangemi G, Barco S, Bonifazio P, Maffia A, Agazzi A, Melioli G. Comparison of Antibody-Conjugated Magnetic Immunoassay and Liquid Chromatography-Tandem Mass Spectrometry for the Measurement of Cyclosporine and Tacrolimus in Whole Blood. Int J Immunopathol Pharmacol 2013; 26:419-26. [DOI: 10.1177/039463201302600214] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The aim of this work is to compare the results of a commercially available liquid chromatography tandem mass spectrometry (LC-MS/MS) method in a clinical pathology laboratory for routine Therapeutic Drug Monitoring (TDM) of cyclosporine (CsA) and tacrolimus (Tacr) in pediatric patients with those obtained with the current antibody-conjugated magnetic immunoassay (ACMIA). Whole blood levels of CsA (n= 135) and Tacr (n=100) were sequentially analyzed by using ACMIA and LC-MS/MS on pediatric transplanted patients. The differences were analyzed by using the Passing Bablok regression analysis and the Bland and Altman test. The LC-MS/MS method showed excellent reproducibility and lower limits of quantification compared to the ACMIA. A linear relationship between ACMIA and LC-MS/MS was obtained for both CsA (r= 0.9449; P<0.0001, 95% CI 0.9234 to 0.9605) and Tacr (r=0.9275; P<0.0001, 95% CI 0.8941 to 0.9506). No significant inter-method biases were observed. The analytical performances of the LC-MS/MS method make it suitable for the accurate measurement of CsA and Tacr in pediatric transplanted patients. However ACMIA results are also accurate and reliable. For this reason the choice of the method to be used in a routine clinical pathology laboratory can be made on the bases of non-analytical considerations such as costs, organization, availability of skilled personnel.
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Affiliation(s)
- G. Cangemi
- Laboratorio Centrale di Analisi, Istituto Giannina Gaslini, Genoa, Italy
| | - S. Barco
- Laboratorio Centrale di Analisi, Istituto Giannina Gaslini, Genoa, Italy
| | - P. Bonifazio
- Laboratorio Centrale di Analisi, Istituto Giannina Gaslini, Genoa, Italy
| | - A. Maffia
- Laboratorio Centrale di Analisi, Istituto Giannina Gaslini, Genoa, Italy
| | - A. Agazzi
- Laboratorio Centrale di Analisi, Istituto Giannina Gaslini, Genoa, Italy
| | - G. Melioli
- Laboratorio Centrale di Analisi, Istituto Giannina Gaslini, Genoa, Italy
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The concentration of cyclosporine metabolites is significantly lower in kidney transplant recipients with diabetes mellitus. Ther Drug Monit 2012; 34:38-45. [PMID: 22210099 DOI: 10.1097/ftd.0b013e318241ac71] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Diabetes mellitus is prevalent among kidney transplant recipients. The activity of drug metabolizing enzymes or transporters may be altered by diabetes leading to changes in the concentration of parent drug or metabolites. This study was aimed to characterize the effect of diabetes on the concentration of cyclosporine (CsA) and metabolites. METHODS Concentration-time profiles of CsA and metabolites (AM1, AM9, AM4N, AM1c, AM19, and AM1c9) were characterized over a 12-hour dosing interval in 10 nondiabetic and 7 diabetic stable kidney transplant recipients. All patients were male, had nonfunctional CYP3A5*3 genotype, and were on combination therapy with ketoconazole. RESULTS The average daily dose (±SD) of CsA was 65 ± 21 and 68 ± 35 mg in nondiabetic and diabetic subjects, respectively (P = 0.550). Cyclosporine metabolites that involved amino acid 1 (AM1, AM19, AM1c) exhibited significantly lower dose-normalized values of area under the concentration-time curve in patients with diabetes. Moreover, during the postabsorption phase (≥3 hours after dose), metabolite-parent concentration ratios for all metabolites, except AM4N, was significantly lower in diabetic patients. The pharmacokinetic parameters of ketoconazole were similar between the 2 groups thus excluding inconsistent ketoconazole exposure as a source of altered CsA metabolism. CONCLUSIONS This study indicates that diabetes mellitus significantly affects the concentration of CsA metabolites. Because CsA is eliminated as metabolites via the biliary route, the decrease in the blood concentration of CsA metabolites during postabsorption phase would probably reflect lower hepatic cytochrome P450 3A4 enzyme activity. However, other mechanisms including altered expression of transporters may also play a role. Results of cyclosporine therapeutic drug monitoring in diabetic patients must be interpreted with caution when nonspecific assays are used.
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Abstract
Due to their narrow therapeutic indices and highly variable pharmacokinetics, therapeutic drug monitoring is necessary to individualize immunosuppressant dosage following organ transplantation. Until recently, monitoring was performed primarily using immunoassays, however, there is an increasing shift to HPLC coupled with MS/MS, due to its greater sensitivity and specificity. Online sample clean-up with either a single analytical column or with 2D chromatography significantly reduces manual handling and is essential to minimize matrix effects and maximize specificity and, coupled with rapid chromatography, allows the simultaneous analysis of the major immunosuppressants, with rapid sample throughput. Thus, LC-MS/MS is an attractive and versatile technique that facilitates rapid development of analytical methods, including new immunosuppressants as they become approved for clinical use.
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Brozmanová H, Perinová I, Halvová P, Grundmann M. Liquid chromatography-tandem mass spectrometry method for simultaneous determination of cyclosporine A and its three metabolites AM1, AM9 and AM4N in whole blood and isolated lymphocytes in renal transplant patients. J Sep Sci 2010; 33:2287-93. [PMID: 20589784 DOI: 10.1002/jssc.201000185] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A LC-MS/MS method was developed and validated for the determination of cyclosporine A (CsA) and its three phase 1 metabolites AM1, AM9, and AM4N in whole blood and lymphocytes isolated on the Histopaque gradient. 200 microL of whole blood was precipitated with 10 mol/L zinc sulfate in acetonitrile/methanol (40:60, v/v) and lymphocytes isolated from 1.5 mL blood were extracted with acetonitrile/methanol (40:60, v/v). The analytes and internal standard cyclosporine D were separated on RP column BEH C18, 2.1 x 50 mm, 1.7 microm using gradient LC-MS/MS analysis in positive electrospray mode. Time of analysis was 5 min. Linearity in blood was 5-2000 microg/L for CsA, AM1, and AM9; 2-500 microg/L for AM4N; and 2-500 microg/L for all substances in lymphocytes. Coefficient of variations was 1.8-9.8% and recovery was 92.0-110.0%. The method was used in early and chronic renal transplant patients for therapeutic drug monitoring of CsA to compare either its share in lymphocytes as target organ or binding to one lymphocyte. The same parameters were calculated for all metabolites tested.
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Affiliation(s)
- Hana Brozmanová
- Department of Clinical Pharmacology of University Hospital and Faculty of Health Studies, University of Ostrava, Ostrava, Czech Republic.
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Abstract
The objective of this study was to evaluate the analytical performance of the Abbott ARCHITECT Cyclosporine (CsA) immunoassay in 7 clinical laboratories in comparison to liquid chromatography/tandem mass spectrometry (LC/MS/MS), Abbott TDx, Cobas Integra 800, and the Dade Dimension Xpand immunoassay. The ARCHITECT assay uses a whole blood specimen, a pretreatment step with organic reagents to precipitate proteins and extract the drug, followed by a 2-step automated immunoassay with magnetic microparticles coated with anti-CsA antibody and an acridinium-CsA tracer. Imprecision testing at the 7 evaluation sites gave a range of total % coefficient of variations of 7.5%-12.2% at 87.5 ng/mL, 6.6%-14.3% at 411 ng/mL, and 5.2%-10.7% at 916 ng/mL. The lower limit of quantification ranged from 12 to 20 ng/mL. Purified CsA metabolites AM1, AM1c, AM4N, AM9, and AM19 were tested in whole blood by the ARCHITECT assay and showed minimal cross-reactivity at all 7 sites. In particular, AM1 and AM9 cross-reactivity in the ARCHITECT assay, ranged from -2.5% to 0.2% and -0.8% to 2.2%, respectively, and was significantly lower than for the TDx assay, in which the values were 3.2% and 16.1%, respectively. Comparable testing of metabolites in the Dade Dimension Xpand assay at 2 evaluation sites showed cross-reactivity to AM4N (6.4% and 6.8%) and AM9 (2.6% and 3.6%) and testing on the Roche Integra 800 showed cross-reactivity to AM1c (2.4%), AM9 (10.7%), and AM19 (2.8%). Cyclosporine International Proficiency Testing Scheme samples, consisting of both pooled specimens from patients receiving CsA therapy as well as whole-blood specimens supplemented with CsA, were tested by the ARCHITECT assay at 6 sites and showed an average bias of -24 to -58 ng/mL versus LC/MSMS CsA and -2 to -37 ng/mL versus AxSYM CsA. Studies were performed with the ARCHITECT CsA assay on patient specimens with the following results: ARCHITECT CsA assay versus LC/MSMS, average bias of 31 ng/mL; ARCHITECT versus the Dade Dimension assay (4 sites), average biases of -7 to -228 ng/mL; ARCHITECT versus AxSYM and TDx, average biases of -4 and -53 ng/mL, respectively. Spearman correlation coefficients were >or=0.89. The ARCHITECT CsA assay has significantly reduced CsA metabolite interference relative to other immunoassays and is a convenient and sensitive semiautomated method to measure CsA in whole blood.
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Development of an Abbott ARCHITECT cyclosporine immunoassay without metabolite cross-reactivity. Clin Biochem 2010; 43:1152-7. [DOI: 10.1016/j.clinbiochem.2010.06.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 06/09/2010] [Accepted: 06/14/2010] [Indexed: 11/24/2022]
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Analysis of thyroid hormones in serum by liquid chromatography-tandem mass spectrometry. Anal Bioanal Chem 2010; 397:1831-9. [PMID: 20437035 DOI: 10.1007/s00216-010-3705-9] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 03/24/2010] [Accepted: 03/29/2010] [Indexed: 11/27/2022]
Abstract
Thyroid hormones are essential hormones for regulating growth and development in humans and wildlife. Methods to monitor precise and low levels of these hormones in serum and tissues are needed to assess overall health, whether from disease considerations or possibly from environmental contaminant exposures. Common and routine methods typically rely upon radioimmunoassays, which can be expensive, and typically only measure thyroxine and 3,3',5-triidothyronine, which can be a limitation in fully evaluating impacts on thyroid regulation. In this study we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous analysis of five thyroid hormones--thyroxine, 3,3',5-triidothyronine, 3,3',5'-triiodothyronine, 3,3'-diiodothyronine, and 3,5-diiodothyronine--in serum samples. The LC-MS/MS parameters were optimized and calibrated over a wide concentration range (1.0-500 ng/mL) with on-column detection limits of 1.5-7.0 pg. With use of spiked bovine serum samples, the mean method recoveries were calculated to be 81.3-111.9% with relative standard deviations of 1.2-9.6% at spiking levels ranging from 10 to 100 ng/mL. This method was compared with measurements made by standard radioimmunoassays and with measurements made in a serum Standard Reference Material (SRM 1951b). Development of this method expands the capacity to measure thyroid hormones by including a larger suite of thyroid hormones, and has promising applications for measuring catabolism of thyroid hormones in vitro.
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Performance evaluation of the new ADVIA Centaur system cyclosporine assay (single-step extraction). Clin Chim Acta 2010; 411:806-11. [PMID: 20188087 DOI: 10.1016/j.cca.2010.02.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 01/22/2010] [Accepted: 02/18/2010] [Indexed: 11/24/2022]
Abstract
BACKGROUND Cyclosporine (CsA) monitoring is essential for transplant success. We report a performance study of the recently released, fully automated Siemens ADVIA Centaur CsA assay. METHODS Whole blood samples from 248 transplant patients were prepared using a new 1-step extraction method. Performance evaluations vs. HPLC-tandem MS (LC-MS/MS), Abbott TDx and AxSYM assays were conducted according to CLSI EP5-A2 and EP9-A2 guidelines. RESULTS The correlation coefficient for LC-MS/MS and ADVIA Centaur was > or = 0.97 at each site, and for each transplant type. Regression analysis yielded y=0.94x+19 for all sites: 95% CI=0.91-0.96 (slope) and 10-28 (intercept). Absolute and relative bias was minimal for C0 and C2 sampling. Centaur vs. Abbott TDx and AxSYM assays: y = 0.72x+6, r = 0.98, 95% CI = 0.70-0.73 (slope), 3-9 (intercept); and y = 0.69x+18, r = 0.97, 95% CI = 0.67-0.71 (slope), 8-27(intercept). Within run CVs were 4.5%-7.1%, total CVs were 5.3%-7.7%. CONCLUSIONS The ADVIA Centaur assay compared favorably with LC-MS/MS and Abbott assays, displaying good correlation for all transplant types and methods.
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Soldin OP, Sharma H, Husted L, Soldin SJ. Pediatric reference intervals for aldosterone, 17alpha-hydroxyprogesterone, dehydroepiandrosterone, testosterone and 25-hydroxy vitamin D3 using tandem mass spectrometry. Clin Biochem 2009; 42:823-7. [PMID: 19318024 DOI: 10.1016/j.clinbiochem.2009.01.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 01/20/2009] [Accepted: 01/23/2009] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To determine age and sex-specific pediatric reference intervals for aldosterone, 17alpha-hydroxyprogesterone, dehydroepiandrosterone, testosterone, and 25-hydroxy vitamin D(3). BACKGROUND AND DESIGN Reference intervals were determined for neonates and children 0-18 years of age. The study was conducted at both Children's National Medical Center and Georgetown University using outpatient blood samples obtained between January 1, 2004 and June 30, 2008. METHODS Serum samples were analyzed using isotope dilution liquid chromatography tandem mass spectrometry (LC/MS/MS) with deuterium-labeled internal standards at Children's National Medical Center and Georgetown University Medical Center Bioanalytical Core Laboratory. RESULTS AND CONCLUSIONS This is the first study to provide pediatric reference intervals of steroid hormones for children from birth to 18 years of age using LC/MS/MS. Reference intervals were established for aldosterone, 17alpha-hydroxyprogesterone, dehydroepiandrosterone, testosterone, and 25-hydroxy vitamin D(3). All the analytes exhibited at least some age dependence. Sex differences between early and late childhood and adolescence were found for 17alpha-hydroxyprogesterone and testosterone. Seasonal differences were apparent for 25-hydroxy vitamin D(3).
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Affiliation(s)
- Offie P Soldin
- Department of Oncology, Georgetown University Medical Center, USA.
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Abstract
Use of prescription and nonprescription medications is common during pregnancy and is required in many women with underlying kidney disease or hypertension and in all with solid-organ allografts. Systematic assessment of drug safety during pregnancy is lacking, as are rigorous and comprehensive studies of pharmacokinetics and pharmacodynamics to guide drug selection and dosing across pregnancy. Renal and hepatic clearances of many drugs change markedly during pregnancy and pitfalls may complicate routine therapeutic monitoring of some drugs during pregnancy. However, available data and clinical experience allow reasonable strategies for selection and dosing of immunosuppressive agents in pregnant transplant recipients and of antihypertensive agents in women with mild or more severe hypertension complicating their pregnancies.
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Affiliation(s)
- Jason G Umans
- Penn Medical Laboratory, MedStar Research Institute, Washington, DC, USA.
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22
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Napoli KL. 12-Hour Area Under the Curve Cyclosporine Concentrations Determined by a Validated Liquid Chromatography-Mass Spectrometry Procedure Compared With Fluorescence Polarization Immunoassay Reveals Sirolimus Effect on Cyclosporine Pharmacokinetics. Ther Drug Monit 2006; 28:726-36. [PMID: 17164687 DOI: 10.1097/01.ftd.0000249951.58504.0e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Liquid chromatographic (LC) procedures have been applied to cyclosporine therapeutic drug monitoring (TDM) since the agent was introduced in 1983. In recent years, the advance to mass spectrometric (MS) detection has enhanced the capability of LC by providing more sensitive and selective detection, a wider analytical range, faster turnaround time, and relative ease of use. Although fluorescence polarization immunoassay (FPIA) is a widely popular technology for cyclosporine TDM, it is compromised by a limited analytical range and lack of selectivity for parent drug. Here, we present the validation of an LC-MS procedure that is equally applicable to use on single or tandem quadrupole instruments. An extensive method comparison with FPIA was performed using samples (n = 726) collected for full 12-hour pharmacokinetic studies on 121 renal transplant recipients. Patients were receiving either full-dose cyclosporine or primary sirolimus therapy complimented with low-dose cyclosporine. FPIA overestimated all cyclosporine concentrations to varying degrees depending on hour of collection (12 approximately 0 > 8 > 6 > 4 > 2-hour). The mean FPIA/LC-MS ratio was significantly higher at 0 hour in the presence of sirolimus (P = 0.008) and trended higher at the other collection times and for area under the curve. Sirolimus also had a significant effect on the FPIA/LC-MS ratio at 12 hour in studies with tmax at 2 hours (P = 0.042) but not 4 hours (P = 0.735). Use of LC-MS procedures for cyclosporine TDM provides for quantitation of approximately 20% more samples from patients receiving low-dose cyclosporine and reduces any errors in dosing that may occur because of the sirolimus effect on cyclosporine pharmacokinetics when combined with varying degrees of overestimation of cyclosporine concentrations by FPIA.
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Affiliation(s)
- Kimberly L Napoli
- University of Texas Medical School at Houston, Houston, Texas 77030, USA.
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23
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Abstract
During pregnancy the thyroid is hyperstimulated, resulting in changes in thyroid hormone concentrations. Accurate assessment of thyroid function during pregnancy is critical, for both the initiation of thyroid hormone therapy, and for the adjustment of thyroid hormone dose in those already receiving thyroid hormone. Trimester-specific intervals are especially important during pregnancy when thyroid insufficiency may be associated with adverse obstetric outcome and fetal neurodevelopmental deficits. Gestational age-specific reference intervals are now available for thyroid function tests. Knowing the expected normal changes in hormone concentrations throughout pregnancy allows individualized supplementation when necessary.
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Affiliation(s)
- Offie P Soldin
- Department of Medicine, Division of Endocrinology and Metabolism, Lombardi Cancer Center, Washington, DC 20057-1465, USA.
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24
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Guo T, Taylor RL, Singh RJ, Soldin SJ. Simultaneous determination of 12 steroids by isotope dilution liquid chromatography-photospray ionization tandem mass spectrometry. Clin Chim Acta 2006; 372:76-82. [PMID: 16707118 DOI: 10.1016/j.cca.2006.03.034] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2006] [Revised: 03/16/2006] [Accepted: 03/17/2006] [Indexed: 11/22/2022]
Abstract
BACKGROUND Serum steroid assays play an important role in the clinical evaluation of a number of common endocrine disorders. Among various assays, tandem mass spectrometry (MS/MS) has being increasingly applied in clinical laboratories for its high sensitivity, specificity, and simultaneous multi-analyte quantitation capability. Our first generation isotope dilution steroid profile assay by HPLC-tandem MS/MS with a C-18 column allowed for the measurement of 9 steroids in 18 min employing a sample volume of 760 ul serum. We describe our second generation steroid profile assay which allows for the quantitation of 12 steroids simultaneously employing HPLC-MS/MS and isotope dilution tandem MS in 11 min. This method requires a sample volume of 200 microl. METHODS An API-5000 triple-quadrupole mass spectrometer (Sciex, Concord, Canada) coupled with the PhotoSpray source and Shimadzu HPLC system (Shimadzu Scientific Instruments, Columbia, MD) was used employing isotope dilution with deuterium labeled internal standard (IS) for each analyte. Two hundred microliters of serum were deproteinized by adding 300 microl of acetonitrile containing internal standards. After centrifugation, 450 microl of supernatant were diluted with 900 microl of water and 1000 microl aliquot were injected onto a C-8 column. After a 3 min wash the valve was activated to initiate the gradient elution program which eluted the steroids. Quantitation by MRM analysis was performed both in positive ion mode for 11 analytes and in negative ion mode for aldosterone. Within-day and between-day precision, reliability and accuracy of this method were assessed by correlation with other MS/MS and immunoassay methods and by recovery study. RESULTS Within-day CVs were <11.5% for all analytes tested and between-day CVs ranged from 3.5% to 12.2%. The results of the comparison study yield r values ranging between 0.908 and 0.999. Recovery ranged from 90% to 110%. CONCLUSIONS This method can simultaneously measure 12 steroids in serum within 11 min with minimal sample preparation. It can be routinely employed in a clinical environment and is attractive because of its simplicity in sample processing and high throughput.
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Affiliation(s)
- Tiedong Guo
- Bioanalytical Core Laboratory, General Clinical Research Center, Georgetown University, Washington, DC 20007-2197, USA
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25
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Zhang Y, Conrad AH, Thoma R, Conrad GW. Differentiation of diiodothyronines using electrospray ionization tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2006; 41:162-8. [PMID: 16353128 DOI: 10.1002/jms.971] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Diiodothyronines 3,5-diiodothyronine (3,5-T2), 3',5'-diiodothyronine (3',5'-T2), and 3,3'-diiodothyronine (3,3'-T2) are important metabolites of 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyronine (rT3; reverse T3). In this paper, a novel and rapid method for identifying and quantifying 3,5-T2, 3',5'-T2 and 3,3'-T2 has been introduced using electrospray ionization tandem mass spectrometry (ESI-MS/MS). Fragmentation patterns were proposed on the basis of our data obtained by ESI-MS/MS. MS2 spectra in either negative ionization mode or positive ionization mode can be used to differentiate 3,5-T2, 3',5'-T2 and 3,3'-T2. On the basis of the relative abundance of fragment ions in MS2 spectra under the positive ionization mode, quantification of the 3,5-T2, 3',5'-T2 and 3,3'-T2 isomers in mixtures is also achieved without prior separation.
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Affiliation(s)
- Yuntao Zhang
- Division of Biology, Ackert Hall, Kansas State University, Manhattan, Kansas 66506-4901, USA.
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26
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Zhang Y, Conrad AH, Conrad GW. Detection and quantification of 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine by electrospray ionization tandem mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2005; 16:1781-6. [PMID: 16182556 DOI: 10.1016/j.jasms.2005.06.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 06/23/2005] [Accepted: 06/24/2005] [Indexed: 05/04/2023]
Abstract
A novel and rapid method for identifying and quantifying 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyronine (rT3; reverse T3) has been introduced using electrospray ionization tandem mass spectrometry (ESI-MS/MS). MS(2) spectra in either negative ionization mode or positive ionization mode can be used to differentiate T3 and rT3. Quantification of the T3 and rT3 isomers under the negative ionization mode is also achieved without prior separation by HPLC.
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Affiliation(s)
- Yuntao Zhang
- Division of Biology, Kansas State University, Ackert Hall, Manhattan, KS 66506-4901, USA.
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27
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Roberts NB, Dutton J, Higgins G, Allars L. Evaluation of a novel semi-automated HPLC procedure for whole blood cyclosporin A confirms equivalence to adjusted monoclonal values from Abbott TDx. Clin Chem Lab Med 2005; 43:228-36. [PMID: 15843222 DOI: 10.1515/cclm.2005.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The problem in the measurement of cyclosporin (CyA) is that the widely used immuno-based assays suffer from interference by metabolites present in unpredictable excess. To resolve this, the consensus view has been to develop more specific and robust procedures for the measurement of CyA alone in order to give values similar to those obtained by HPLC. We developed an alternative strategy based on Abbott poly- and monoclonal assays to derive an adjusted monoclonal value as an equivalent measurement to HPLC. We have now evaluated a recently developed semi-automated HPLC procedure and used it to test the validity of the adjusted monoclonal value. The automated HPLC procedure with online clean-up was optimised for the separation of CyA and internal standard CyD. The assay was simple to use, precise and gave good recovery of cyclosporin from whole blood. Comparisons with the more specific immunoassays Abbott AxSym and EMIT showed close agreement, whereas Abbott monoclonal values indicated up to 20% positive bias. In contrast, the adjusted monoclonal values gave good agreement with HPLC. Data obtained from HPLC linked to tandem mass spectrometry (MS) indicated closer agreement with Abbott monoclonal values than expected, suggesting some positive bias with MS. The benefit of using an adjusted monoclonal value is that a result equivalent to HPLC is obtained, as well as an indication of the concentration of metabolites from the Abbott polyclonal measurement.
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Affiliation(s)
- Norman B Roberts
- Department of Clinical Biochemistry, The Royal Liverpool and Broadgreen University Hospitals, Liverpool, UK.
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28
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Westley IS, Morris RG, Taylor PJ, Salm P, James MJ. CEDIA® Sirolimus Assay Compared With HPLC-MS/MS and HPLC-UV in Transplant Recipient Specimens. Ther Drug Monit 2005; 27:309-14. [PMID: 15905801 DOI: 10.1097/01.ftd.0000164394.47520.12] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The role of the therapeutic drug monitoring laboratory in support of immunosuppressant drug therapy is well established, and the introduction of sirolimus (SRL) is a new direction in this field. The lack of an immunoassay for several years has restricted the availability of SRL assay services. The recent availability of a CEDIA SRL assay has the potential to improve this situation. The present communication has compared the CEDIA SRL method with 2 established chromatographic methods, HPLC-UV and HPLC-MS/MS. The CEDIA method, run on a Hitachi 917 analyzer, showed acceptable validation criteria with within-assay precision of 9.1% and 3.3%, and bias of 17.1% and 5.8%, at SRL concentrations of 5.0 microg/L and 20 microg/L, respectively. The corresponding between-run precision values were 11.5% and 3.3% and bias of 7.1% and 2.9% at 5.0 microg/L and 20 microg/L, respectively. The lower limit of quantification was found to be 3.0 microg/L. A series of 96 EDTA whole-blood samples predominantly from renal transplant recipients were assayed by the 3 methods for comparison. It was found that the CEDIA method showed a Deming regression line of CEDIA=1.20xHPLC-MS/MS-0.07 (r=0.934, SEE=.47), with a mean bias of 20.4%. Serial blood samples from 8 patients included in this evaluation showed that the CEDIA method reflected the clinical fluctuations in the chromatographic methods, albeit with the variable bias noted. The CEDIA method on the H917 analyzer is therefore a useful adjunct to SRL dosage individualization in renal transplant recipients.
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Affiliation(s)
- Ian S Westley
- Department of Cardiology and Clinical Pharmacology, The Queen Elizabeth Hospital, Woodville, South Australia 5011, Australia
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29
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Cattaneo D, Zenoni S, Murgia S, Merlini S, Baldelli S, Perico N, Gotti E, Ottomano C, Crippa A, Remuzzi G. Comparison of different cyclosporine immunoassays to monitor C0 and C2 blood levels from kidney transplant recipients: Not simply overestimation. Clin Chim Acta 2005; 355:153-64. [PMID: 15820490 DOI: 10.1016/j.cccn.2004.12.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Revised: 12/23/2004] [Accepted: 12/23/2004] [Indexed: 11/15/2022]
Abstract
BACKGROUND Immunoassays used for the measurement of cyclosporine (CsA) usually show cross-reactivity for CsA metabolites, usually resulting in unacceptable bias. METHODS To assess the performance of different immunoassays, CsA concentrations were analyzed in 132 samples using ACMIA, EMIT-VIVA, CEDIA-PLUS, and HPLC. Samples were collected from kidney transplant patients monitored with the traditional blood CsA trough level (C0, n=73) and the new sampling at 2-h post CsA dosing (C2, n=59). RESULTS Overall, the correlations between HPLC and other methods were good (r values ranging from 0.85 to 0.97). The use of C2 concentrations to monitor CsA exposure were associated with an overall better performance of all the immunoassays as compared with C0 values. However, none of the immunoassays agreed with the guidelines proposed in the Lake Louis Consensus Conference. Of note, the CEDIA-PLUS was the only that provided a linear relationship with HPLC for both sampling times. A false positive case associated with ACMIA was also documented in blood samples from a patient withdrawn from CsA for 1 month. CONCLUSION These data suggest that the performance of some of the most used immunoassays is not satisfactory, eventually leading to incorrect therapeutic decision guided by erroneous CsA monitoring.
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Affiliation(s)
- Dario Cattaneo
- Department of Medicine and Transplantation, Ospedali Riuniti di Bergamo-Mario Negri Institute for Pharmacological Research, Bergamo, Italy.
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30
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Soldin OP, Hilakivi-Clarke L, Weiderpass E, Soldin SJ. Trimester-specific reference intervals for thyroxine and triiodothyronine in pregnancy in iodine-sufficient women using isotope dilution tandem mass spectrometry and immunoassays. Clin Chim Acta 2005; 349:181-9. [PMID: 15469872 PMCID: PMC3625638 DOI: 10.1016/j.cccn.2004.06.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2004] [Revised: 06/24/2004] [Accepted: 06/24/2004] [Indexed: 11/24/2022]
Abstract
BACKGROUND Accurate assessment of the pregnant woman's thyroid status is critical, for both the initiation of thyroid hormone therapy and for the adjustment of thyroid hormone dose in those already receiving thyroid hormone. Trimester-specific intervals are especially important during pregnancy when thyroid insufficiency may be associated with adverse obstetric outcome and fetal neurodevelopmental deficits. We defined pregnancy-specific reference intervals for thyroxine (T4) and 3,5,3'-triiodothyronine (T3). We used a novel isotope dilution tandem mass spectrometry (LC/MS/MS) method, and compare these to reference intervals obtained by immunoassays (IAs) performed on the same samples. METHODS Concentrations of circulating T4 and T3 were measured simultaneously during first, second and third trimesters and postpartum in iodine-sufficient, healthy, singleton pregnancies using API-3000 LC/MS/MS with deuterium-labeled internal standard (L-thyroxine-d2). Immunoassays were conducted on the same samples (T4 Dade Behring RxL, T3 DPC-Immunolite). RESULTS Linear regression is reported for method comparisons; for T4, the slope decreased from r=0.900 in nonpregnant women to 0.802-0.820 during pregnancy. For T3, correlations between LC/MS/MS and immunoassays were weaker in all cases (r=0.407-0.574). CONCLUSION In this longitudinal study, we established trimester-specific reference intervals for T4 and T3 by LC/MS/MS and compare these to intervals obtained by immunoassays.
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Affiliation(s)
- O P Soldin
- Division of Cancer Genetics and Epidemiology, Lombardi Cancer Center, Georgetown University Medical Center, Room S-165-A, Washington, DC 20007-2197, USA.
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31
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Karamperis N, Koefoed-Nielsen P, Bagger Sørensen A, Højskov C, Poulsen J, Jørgensen K. Role of metabolites and calcineurin inhibition on C2 monitoring in renal transplant patients. Nephrol Dial Transplant 2005; 20:618-21. [PMID: 15671072 DOI: 10.1093/ndt/gfh671] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Many transplantation centres have switched to C2 monitoring of cyclosporin-treated renal transplant patients. The rationale is that the C2 correlates best with AUC0-4 (area under the concentration-time curve), which again correlates with rejection and nephrotoxicity. It has also been demonstrated that calcineurin phosphatase is inhibited maximally 1-2 h after intake of cyclosporin in patients receiving their first dose. Cyclosporin is metabolized to many compounds, which may influence the results of immunoassays. Some metabolites may have immunosuppressive activity. METHODS Cyclosporin metabolites were added to whole blood from healthy volunteers and the calcineurin phosphatase activity (CaN) was determined. Twenty renal transplant patients at varying times after transplantation had blood samples drawn in the morning before and 1, 2, 3 and 4 h after intake of their usual dose of cyclosporin microemulsion. Whole blood samples were analysed by liquid chromatography/tandem mass spectrometry for cyclosporin blood concentration and for the cyclosporin metabolites AM1, AM9, AM1c and AM4n. All samples were analysed for CaN utilizing a 32P-labelled 19 amino-acid peptide. RESULTS The concentrations of AM1c and AM4n were very low and cannot contribute to CaN inhibition. The ratio of AM1 and AM9 to cyclosporin was high before intake of the drug, but it was much lower during the following 4 h. The 2-h values of cyclosporin were the best predictors of AUC0-4. Calcineurin phosphatase was most inhibited in the 2-h samples and the 2-h value of CaN was the best predictor of CaN AUC0-4. The correlation with calcineurin inhibition seemed better for cyclosporin plus metabolites than for cyclosporin. CONCLUSIONS Samples collected at 2 h are the best predictors of AUC0-4 for both cyclosporin and calcineurin inhibition. The impact of metabolites appears to be small; however, the temporal profile of calcineurin inhibition seemed to follow cyclosporin plus metabolites better than cyclosporin alone.
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Affiliation(s)
- Nikolaos Karamperis
- Research Laboratory, Department of Renal Medicine C, Skejby Sygehus, Arhus University Hospital, Arhus, Denmark
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Westley IS, Sallustio BC, Morris RG. Evaluation of the immunotech cyclosporine direct radioimmunoassay for the determination of whole-blood cyclosporine in renal transplant patients. Ther Drug Monit 2005; 27:90-3. [PMID: 15665752 DOI: 10.1097/00007691-200502000-00016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Therapeutic drug monitoring (TDM) of cyclosporine (CsA) has been an accepted as an essential tool in the management of solid organ transplant recipients. The authors evaluated a new CsA method, Immunotech cyclosporine direct radioimmunoassay (Beckman Coulter, Prague, Czech Republic), for the measurement of whole-blood CsA concentrations. The performance was compared with CEDIA Plus method as well as group mean data for HPLC and other immunoassays available from the International CsA Proficiency Testing Program (www.bioanalytics.co.uk). Regression analysis of patient samples gave a relationship of RIA = 1.0822 CEDIA(+) + 69.84 (r(2) = 0.933). External CsA-spiked proficiency-testing (PT) samples gave a regression equation of RIA = 0.9672 CEDIA(+) + 4.99 (r(2) = 0.996). The correlation with the CEDIA Plus method using patient specimens (hence, including CsA metabolites) suggested that the test RIA method possibly had slightly inferior specificity for parent CsA. The results suggest that the Immunotech cyclosporine direct RIA kit is suitable for the measurement of whole-blood CsA concentrations and maintained clinically acceptable analytic precision and accuracy, displaying CVs of less than 15% and biases of less than 10%. The PT program CsA-metabolite-free samples showed that calibration between methods was comparable with the possible exception of mFPIA/TDx.
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Affiliation(s)
- Ian S Westley
- Department of Clinical Pharmacology, The Queen Elizabeth Hospital, Woodville, South Australia, Australia 5011.
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33
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Morris RG. Immunosuppressant Drug Monitoring: Is the Laboratory Meeting Clinical Expectations? Ann Pharmacother 2005; 39:119-27. [PMID: 15590877 DOI: 10.1345/aph.1e287] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE: To review the literature relating to immunosuppressant drug measurement as performed in therapeutic drug monitoring laboratories associated with transplantation centers and consider whether the assay methods widely used for patient dosage management achieve acceptable quality criteria in the context of other sources of variability with these drugs. DATA SOURCES: Articles used were accessed primarily through MEDLINE, as well as references cited in related publications. Searches were restricted to organ transplantation in humans. STUDY SELECTION AND DATA EXTRACTION: Emphasis was placed on the literature relating to the quality of immunosuppressant drug assays, their limitations, and evidence of clinical benefit in dosage individualization. DATA SYNTHESIS: There is a dilemma evident between the quality of the analytical services offered by some diagnostic immunoassay manufacturers and the ability of a significant number of clinical laboratories globally to select only appropriate assay methods. CONCLUSIONS: In many cases, clinical laboratories fail to meet the reasonable clinical expectations required for interpretation of immunosuppressant drug assay results as an adjunct to optimal dosage individualization and patient care.
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Affiliation(s)
- Raymond G Morris
- Clinical Pharmacology Laboratory, The Queen Elizabeth Hospital, Woodville SA, Australia
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34
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Papadea C, Lage JM. Immunosuppressants testing in transplantation. Arch Pathol Lab Med 2004; 128:1328-9. [PMID: 15578873 DOI: 10.5858/2004-128-1328c-itit] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Soukhova N, Soldin OP, Soldin SJ. Isotope dilution tandem mass spectrometric method for T4/T3. Clin Chim Acta 2004; 343:185-90. [PMID: 15115693 PMCID: PMC3634919 DOI: 10.1016/j.cccn.2004.01.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Revised: 01/16/2004] [Accepted: 01/19/2004] [Indexed: 11/22/2022]
Abstract
BACKGROUND The thyroid hormones thyroxine (T4) and 3,5,3'-triidothyronine (T3) are essential for regulating a number of biological processes, including growth, neurodevelopment, carbohydrate metabolism, oxygen consumption and protein synthesis. Immunoassays are the current methods for thyroid hormone measurement and suffer from a lack of specificity. Our objective was to simultaneously measure T4 and T3 using isotope dilution tandem mass spectrometry within a single run. To compare the results obtained by this MS/MS method with those obtained by an immunoassay procedure on the same samples (DPC Immulite for T3, Diagnostics Product, and Dade RxL Dimension for T4, Dade-Behring). METHODS An API-3000 tandem mass spectrometer (SCIEX, Toronto, Canada) equipped with TurboIonSpray and Shimadzu HPLC system was used employing isotope dilution with deuterium-labeled internal standard (l-thyroxin-d2). The method requires 100 microl of serum and involves addition of internal standard, precipitation of proteins with methanol and injection of the supernatant onto a C-18 column. After washing, the switch valve is activated and T4 and T3 eluted using a methanol gradient. T4 and T3 by immunoassay were performed using the Dade RxL Dimension and the DPC Immulite, respectively. RESULTS AND CONCLUSIONS An isotope dilution tandem mass spectrometry method for the simultaneous determination of total T4 and T3 in serum is described which is accurate, specific, precise (%CVs 3.5-9.0), simple and fast (<7 min).
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Affiliation(s)
- Nadia Soukhova
- Bioanalytical Core Laboratory, Georgetown Clinical Research Center, Georgetown University, USA
| | - Offie P. Soldin
- Division of Cancer Genetics and Epidemiology, Lombardy Cancer Center, Georgetown University, USA
| | - Steven J. Soldin
- Bioanalytical Core Laboratory, Georgetown Clinical Research Center, Georgetown University, USA
- Departments of Pharmacology and Endocrinology, Georgetown University, USA
- Department of Laboratory Medicine, Children’s National Medical Center and Departments of Pediatrics and Pathology, The George Washington University School of Medicine, Washington, DC, USA
- Corresponding author. Bioanalytical Core Laboratory, Georgetown Clinical Research Center, GM-12A Pre Clinical Science Building, 3900 Reservoir Road NW, Washington, DC 20007-2197, USA. Tel.: +1-202-687-8038. (S.J. Soldin)
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36
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Kagawa Y, Yanagawa M, Muraki Y, Iwamoto T, Mizutani H, Sugimura Y, Kojima M. Comparison of cyclosporine concentrations in renal transplant recipients using ACMIA and mFPIA methods. Clin Biochem 2004; 37:1016-21. [PMID: 15498531 DOI: 10.1016/j.clinbiochem.2004.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Revised: 04/02/2004] [Accepted: 07/20/2004] [Indexed: 11/19/2022]
Abstract
OBJECTIVE This study investigated the performance and data comparability of a new, relatively specific immunoassay method, affinity column mediated immunoassay (ACMIA) run on the Dimension Xpand-HM, and the established less specific monoclonal fluorescence polarization immunoassay (mFPIA) method on the TDx analyzer (mFPIA/TDx) in determining cyclosporine (CsA) concentrations. METHODS Accuracy and within and between-run precision were tested. Then we measured CsA concentrations of 216 samples obtained from 51 patients and divided the 113 samples from 21 patients with renal transplants into two groups based on sampling time. RESULTS Accuracy relative to the four weighed-in concentrations ranged from 99% to 104% and from 106% to 117% for ACMIA and mFPIA/TDx, respectively. The mean within-run precision (CV%) for the ACMIA and mFPIA/TDx methods was 4.31% and 2.57%, respectively. The mean recovery for ACMIA and mFPIA/TDx in the between-run study was 104.50% and 111.12%, respectively. The mFPIA/ACMIA ratio (the ratio of the concentration measured by mFPIA/TDx to that measured by ACMIA) of C2-3 (concentrations measured 2-3 h after oral administration) was 118.85%, which was significantly smaller than that (139.12%) of C8-12 (those measured more than 8 h after the administration) at each mean concentration. CONCLUSIONS These results indicate that ACMIA is more accurate than mFPIA/TDx, and the difference in the mFPIA/ACMIA ratio between C2-3 and C8-12 was due to the difference in the relative cross-reactivity with CsA metabolites. Although mFPIA/TDx had an apparent calibration error, both methods had a clinically acceptable within and between-run precision.
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Affiliation(s)
- Yoshiyuki Kagawa
- Department of Hospital Pharmacy, Mie University School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan.
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37
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Holst JP, Soldin OP, Guo T, Soldin SJ. Steroid hormones: relevance and measurement in the clinical laboratory. Clin Lab Med 2004; 24:105-18. [PMID: 15157559 PMCID: PMC3636985 DOI: 10.1016/j.cll.2004.01.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Steroid hormones are synthesized in the adrenal cortex, the gonads, and the placenta; are all derived from cholesterol and many are of clinical importance. This article addresses the relevance and methods of measurement of steroid hormones in the clinical laboratory.
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Affiliation(s)
- Jennifer P. Holst
- Division of Endocrinology and Metabolism, Georgetown University, 4000 Reservoir Road Northwest, Washington, DC 20007, USA
| | - Offie P. Soldin
- Division of Cancer Genetics and Epidemiology, Lombardy Cancer Center, Georgetown University, 3800 Reservoir Road Northwest, Washington DC 20007, USA
| | - Tiedong Guo
- Bioanalytical Core Laboratory, Georgetown Clinical Research Center, Georgetown University, 3900 Reservoir Road Northwest, Washington DC, 20007, USA
| | - Steven J. Soldin
- Bioanalytical Core Laboratory, Georgetown Clinical Research Center, Georgetown University, 3900 Reservoir Road Northwest, Washington DC, 20007, USA
- Department of Endocrinology and Pharmacology, Georgetown University, 4000 Resevoir Road, Washington, DC 20007, USA
- Departments of Laboratory Medicine, Childrens National Medical Center, 111 Michigan Avenue Northwest, Washington, DC 20010, USA
- Corresponding author. Department of Laboratory Medicine, Children’s National Medical Center, 111 Michigan Avenue Northwest, Washington, DC 20010. (S.J. Soldin)
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Guo T, Chan M, Soldin SJ. Steroid profiles using liquid chromatography-tandem mass spectrometry with atmospheric pressure photoionization source. Arch Pathol Lab Med 2004; 128:469-75. [PMID: 15043485 DOI: 10.5858/2004-128-469-spulcm] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tiedong Guo
- Bioanalytical Core Laboratory, Georgetown University and Georgetown Clinical Research Center, Washington, DC, USA
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Affiliation(s)
- David W Holt
- Analytical Unit, St. Georges Hospital Medical School, London, England.
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Morris RG, Holt DW, Armstrong VW, Griesmacher A, Napoli KL, Shaw LM. Analytic Aspects of Cyclosporine Monitoring, on Behalf of the IFCC/IATDMCT Joint Working Group. Ther Drug Monit 2004; 26:227-30. [PMID: 15228170 DOI: 10.1097/00007691-200404000-00025] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The use of therapeutic drug monitoring strategies for cyclosporin (CsA) has evolved markedly in recent years since previous consensus guidelines were presented. Apart from the introduction of some new methods, the major change has been the shift away from the traditional predose/trough (C0) sample. The most popular alternative has been shown to be a 2-hour postdose (C2) sample. This has presented a challenge to clinical laboratories where typical C2 sample concentrations exceed the upper limit of the calibration range for their chosen CsA method, hence requiring an accurate dilution to be performed. Data from the Australian/New Zealand survey, as well as that in the International CsA Proficiency Testing Program, have demonstrated both a plethora of dilution protocols and resultant widespread failure of many laboratories to obtain accurate results. This paper compares data from several independent sources, pointing to international problems for reliable CsA measurement in clinical laboratories. This includes the CsA method selection criteria adopted by a large percentage of laboratories in various surveys, indicating that the least specific mFPIA methods have been widely adopted.
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Affiliation(s)
- Raymond G Morris
- Department of Cardiology and Clinical Pharmacology, The Queen Elizabeth Hospital, Woodville, South Australia 5011, Australia.
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Abstract
The advent of cyclosporine 20 years ago was a major advance in the field of solid organ transplantation. Its use enabled directed immunosuppression with a consequent decrease in the incidence of graft failure, acute rejection, and systemic infection. The early oil-based preparation, however, was difficult to administer and had limited bioavailability and unpredictable pharmacokinetics. The drug also has a fairly narrow therapeutic window with major long-term side effects, which include nephrotoxicity, malignancy, hyperlipidemia, and hypertension. The introduction of a microemulsion preparation (Neoral) with improved bioavailability has been associated with lower rates of rejection and comparable tolerability, therefore allowing the use of lower doses. Traditionally cyclosporine toxicity has been minimized by monitoring trough levels. Monitoring of levels 2 hours after dosing may provide a more accurate determination of cyclosporine exposure. The next phase in cardiac transplantation immunosuppression will most likely see a significantly diminished role for cyclosporine with the introduction of newer, more potent immunosuppressive agents with more favorable side-effect profiles. These agents, which include mycophenolate mofetil, sirolimus, and everolimus, also hold the promise of having a major impact on the development of transplant vasculopathy, which up to now has been an important determinant of limiting long-term allograft survival.
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Affiliation(s)
- J K Patel
- Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, Calif 90045, USA
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