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Merrigan SD, Kish-Trier E, Seegmiller JC, Johnson-Davis KL. LC-MS/MS method for quantitation of mycophenolic acid, mycophenolic acid acyl-glucuronide, and 7-O-mycophenolic acid glucuronide in serum. CLINICAL MASS SPECTROMETRY (DEL MAR, CALIF.) 2017; 3:41-48. [PMID: 39193102 PMCID: PMC11322753 DOI: 10.1016/j.clinms.2017.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 07/05/2017] [Accepted: 07/07/2017] [Indexed: 11/18/2022]
Abstract
Mycophenolic acid (MPA) is the active metabolite of the immunosuppressant drug mycophenolate mofetil (MMF), which is commonly prescribed after organ transplantation in conjunction with other immunosuppressants. MMF therapy is monitored to balance therapeutic efficacy with minimizing adverse effects associated with high serum concentrations. A LC-MS/MS method was developed for the quantification of MPA and two additional metabolites, 7-O-mycophenolic acid glucuronide (MPAG) and mycophenolic acid acyl-glucuronide (AcMPAG), in serum using reverse-phase chromatography and multiple reaction monitoring (MRM) in positive electrospray ionization mode. Analytes were chromatographically resolved and the method was linear from 0.5 to 30.0 µg/ml MPA, 4.7 to 300 µg/ml MPAG, and from 0.5 to 30.0 µg/ml AcMPAG. Calibration curves for all analytes had r ≥ 0.990. Intra- and inter-assay imprecision coefficients of variation (CVs) were ≤6.9% and ≤14.5%, respectively. No ion suppression or interferences were observed. The method compared favorably with an unaffiliated reference laboratory. Retrospective data analyses indicate interpatient differences in drug metabolism.
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Affiliation(s)
- Stephen D. Merrigan
- ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, United States
| | - Erik Kish-Trier
- ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, United States
| | - Jesse C. Seegmiller
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Kamisha L. Johnson-Davis
- ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, United States
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT, United States
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Abstract
Since the early 1980s, the combination of cyclosporine, azathioprine, and prednisone has been the mainstay tripledrug immunosuppressive regimen used in transplantation. However, advances in drug research, design, and development have allowed for the introduction of new agents that have greatly increased the number of immunosuppressive agents available for use in transplant recipients. Particularly, the newer antiproliferative immunosuppressive drugs (agents that directly inhibit the proliferation of T and B lymphocytes) have had an important impact on patient outcomes posttransplant. These agents are mycophenolate mofetil and sirolimus.
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Affiliation(s)
- Theodore M. Sievers
- Transplant Pharmacokinetic Laboratory, Dumont-UCLA Transplant Center, 10833 LeConte Avenue, Room 77-120, Los Angeles, CA 90025
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Simultaneous quantification of IMPDH activity and purine bases in lymphocytes using LC-MS/MS: assessment of biomarker responses to mycophenolic acid. Ther Drug Monit 2014; 36:108-18. [PMID: 24061448 DOI: 10.1097/ftd.0b013e3182a13900] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The development of biomarkers describing the individual responses to the immunosuppressant mycophenolic acid (MPA) has focused on the target enzyme activity [inosine 5'-monophosphate dehydrogenase (IMPDH)]. An extended strategy is to quantify the metabolic consequences of IMPDH inhibition. The aim of this study was to develop an assay for quantification of IMPDH activity and related purine bases and to provide preliminary data on the behavior of these biomarkers during clinical exposure to MPA. METHODS Liquid chromatography-mass spectrometry was used to determine xanthine (IMPDH activity in incubated cell lysate), hypoxanthine, guanine, and adenine derived from free nucleotides in lymphocytes. Analytical performance was assessed, and the biomarkers were examined in CD4⁺ cells from 2 groups: Healthy individuals in a single-dose MPA study (n = 5) and liver transplant recipients on MPA therapy (n = 15). RESULTS Coefficients of variation between series were below 10% and 15% for measurement of the purines and IMPDH activity, respectively. Although IMPDH was inhibited, the purine levels increased in response to MPA in 3 of the 5 healthy individuals, and this positive response seemed to be associated with IMPDH1 c.579 + 119 G/G and c.580 - 106 G/G. In the liver transplant study, guanine was not reduced in response to the transient drop in IMPDH activity after MPA dosing. However, there were trends toward decrease in guanine and elevation of hypoxanthine during prolonged MPA therapy. The guanine/hypoxanthine ratio (median) was 37% lower and the adenine level was 21% lower at day 17 compared with day 4 after transplantation. CONCLUSIONS The assay allows precise quantification of IMPDH activity, hypoxanthine, guanine, and adenine in lymphocytes. Some individuals may possess a counteracting purine response to the MPA-mediated inhibition of IMPDH. Reduction of the guanine/hypoxanthine ratio may be related to prolonged inhibition of IMPDH and seems as an intriguing pharmacodynamic biomarker for MPA.
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Shao J, Katika MR, Schmeits PCJ, Hendriksen PJM, van Loveren H, Peijnenburg AACM, Volger OL. Toxicogenomics-based identification of mechanisms for direct immunotoxicity. Toxicol Sci 2013; 135:328-46. [PMID: 23824090 DOI: 10.1093/toxsci/kft151] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Compounds with direct immunotoxic properties, including metals, mycotoxins, agricultural pesticides, and industrial chemicals, form potential human health risks due to exposure through food, drinking water, and the environment. Insights into the mechanisms of action are currently lacking for the majority of these direct immunotoxicants. Therefore, the present work aimed to gain insights into the molecular mechanisms underlying direct immunotoxicity. To this end, we assessed in vitro the effects of 31 test compounds on the transcriptome of the human Jurkat T-cell line. These compounds included direct immunotoxicants, immunosuppressive drugs with different mode of actions, and nonimmunotoxic control chemicals. Pathway analysis of the microarray data allowed us to identify canonical pathways and Gene Ontology processes that were transcriptionally regulated in common by immunotoxicants (1) with structural similarities, such as tributyltin chloride and tributyltin oxide that activated the retinoic acid/X receptor signaling pathway and (2) without structural similarities, such as As2O3, dibutyltin chloride, diazinon, MeHg, ochratoxin A (OTA), S9-treated OTA, S9-treated cyclophosphamide, and S9-treated benzo[a]pyrene, which activated unfolded protein response, and FTY720, lindane, and propanil, which activated the cholesterol biosynthesis pathway. In addition, processes uniquely affected by individual immunotoxicants were identified, such as the induction of Notch receptor signaling and the downregulation of acute-phase response genes by OTA. These findings were validated by quantitative real-time PCR analysis of genes involved in these processes. Our study indicated that diverse modes of action are involved in direct immunotoxicity and that a set of pathways or genes, rather than one single gene, can be used to screen compounds for direct immunotoxicity.
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Affiliation(s)
- Jia Shao
- * RIKILT-Institute of Food Safety, Wageningen University and Research Centre, 6700 AE Wageningen, The Netherlands
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Glander P, Hambach P, Liefeldt L, Budde K. Inosine 5'-monophosphate dehydrogenase activity as a biomarker in the field of transplantation. Clin Chim Acta 2011; 413:1391-7. [PMID: 21889500 DOI: 10.1016/j.cca.2011.08.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/09/2011] [Accepted: 08/16/2011] [Indexed: 11/25/2022]
Abstract
Inosine 5'monophosphate dehydrogenase (IMPDH) is the rate limiting enzyme in the de novo synthesis of guanine nucleotides. The direct determination of target enzyme activity as a biomarker of mycophenolic acid (MPA) may help to estimate better the individual response to the immunosuppressant. However, the assessment of the clinical utility of this approach is limited by the diversity of the assay systems, which has not yet allowed the prospective assessment of this enzyme in larger patient cohorts. A recently validated and standardized assay allows the investigation of IMPDH activity in larger clinical studies. Although descriptive results from observational studies hold promise for a more individualized therapy in transplant medicine, more studies are needed to prospectively validate this approach.
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Affiliation(s)
- Petra Glander
- Charite-Universitätsmedizin Berlin, Department of Nephrology, Berlin, Germany.
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Abstract
Pharmacokinetic drug monitoring has been used for many years to relate immunosuppressant dose to drug exposure in vivo. However, this conventional therapeutic drug monitoring of blood immunosuppressant levels may not necessarily predict the pharmacologic effects on immune cells. The direct determination of target enzyme activity (eg, calcineurin activity, inosine-5'-monophospahte dehydrogenase [IMPDH] activity, p70S6 kinase) may help to better assess the individual response to the immunosuppressant. However, its use is limited by the difficulties of the assay systems, which did not allow yet the prospective assessment of these enzymes in larger patient cohorts with the establishment of validated pharmacodynamic drug monitoring. The most progress regarding a robust and reproducible test system has been achieved with the determination of IMPDH activity as a specific pharmacodynamic parameter of mycophenolic acid activity. This recently validated and standardized assay allows the investigation of IMPDH activity in larger clinical studies. Although the determination of target enzyme activity, eg, by the determination of IMPDH activity, holds promise for a more individualized therapy in transplant medicine, more studies are needed to prospectively validate this approach.
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Sabbatini M, Uccello F, Serio V, Troncone G, Varone V, Andreucci M, Faga T, Pisani A. Effects of mycophenolate mofetil on acute ischaemia-reperfusion injury in rats and its consequences in the long term. Nephrol Dial Transplant 2009; 25:1443-50. [DOI: 10.1093/ndt/gfp710] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Vethe NT, Bremer S, Bergan S. IMP dehydrogenase basal activity in MOLT-4 human leukaemia cells is altered by mycophenolic acid and 6-thioguanosine. Scandinavian Journal of Clinical and Laboratory Investigation 2008; 68:277-85. [PMID: 18609073 DOI: 10.1080/00365510701724871] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Depletion of guanine and deoxyguanine nucleotides by inhibition of inosine 5'-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205) or introduction of 6-thioguanine nucleotide antimetabolites are two principles of retarding cell proliferation by interference with the cellular purine nucleotide pool. IMPDH activity may be a promising pharmacodynamic biomarker during immunosuppressive and anticancer pharmacotherapy. The aim of the study was to investigate the impact of mycophenolic acid (MPA) and 6-thioguanosine (tGuO) on IMPDH basal activity. MATERIAL AND METHODS We studied the IMPDH basal activity (i.e. the enzyme activity following inhibitor exposure, but measured in absence of the inhibitor) in response to increasing concentrations of the IMPDH inhibitor MPA and the antimetabolite tGuO in MOLT-4 human leukaemia cells. In parallel, IMPDH gene expression and cellular purine nucleotide concentrations were examined. RESULTS A biphasic concentration-dependent influence of MPA on the IMPDH basal activity was observed. At concentrations < or =IC50, MPA increased the IMPDH basal activity. The increase was associated with elevated expression of IMPDH2. Despite increased expression, the basal enzyme activity decreased following exposure to high MPA concentrations. The IMPDH2 expression increased modestly in response to tGuO exposure. However, the IMPDH basal activity decreased when the cells were exposed to a proliferation-blocking tGuO concentration. CONCLUSIONS These findings demonstrate that IMPDH basal activity is influenced by MPA and tGuO, and suggest that reduced IMPDH basal activity is related to the proliferation-blocking effects of these agents.
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Affiliation(s)
- N T Vethe
- Department of Medical Biochemistry, Rikshospitalet Medical Centre, Oslo, Norway
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Vethe NT, Bergan S. Determination of inosine monophosphate dehydrogenase activity in human CD4+ cells isolated from whole blood during mycophenolic acid therapy. Ther Drug Monit 2007; 28:608-13. [PMID: 17038874 DOI: 10.1097/01.ftd.0000245680.38143.ca] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inosine 5'-monophosphate dehydrogenase (IMPDH) is an established target in immunosuppression following organ transplantation. In lymphocytes, reversible inhibition of this enzyme by mycophenolic acid (MPA) results in reduced production of guanine and deoxyguanine nucleotides and thereby retarded proliferation of activated cells. In order to examine MPA pharmacodynamics in renal allograft recipients, the authors have developed an assay for the determination of IMPDH activity in CD4+ cells directly isolated from a small blood volume. Paramagnetic beads coated with anti-CD4 antibodies were utilized for the cell isolation. The intracellular MPA concentration was restored by incubating the cells in microfiltrated plasma from the original sample. Inosine 5'-monophosphate (IMP; substrate) and nicotine adenine dinucleotide (NAD; co-factor) were added to cell lysates, and IMPDH activity was quantified as the xanthosine 5'-monophosphate (XMP) production rate (pmol/10 cells/min) determined by liquid chromatography after hydrolytic cleavage to xanthine. The reaction kinetics were saturated with IMP and NAD concentrations of 1.79 micromol/L and 0.38 micromol/L, respectively. The production rate was linear in the interval 0.13 to 8.7 pmol XMP/min. Total interseries CVs based on seven replicates at each MPA concentration 0, 2.2, and 8.6 microg/mL were 25%, 16%, and 13%, respectively. When a single 1 gram mycophenolate mofetil dose was administered to a healthy individual, the measured IMPDH activity was 13% of predose value at the MPA peak concentration. The present assay allows reliable determination of IMPDH activity in CD4+ cells during MPA exposure, reducing the potential influence of sample preparation on the measured enzyme activity to a minimum. The assay may be applied to assess MPA pharmacodynamics during immunosuppressive treatment, maintaining the influence of intracellular MPA on the IMPDH activity.
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Affiliation(s)
- Nils Tore Vethe
- Department of Medical Biochemistry, Rikshospitalet University Hospital, Oslo, Norway
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Devyatko E, Zuckermann A, Bohdjalian A, Roedler S, Dunkler D, Grimm M, Weigel G. Activation of the purine salvage pathway in mononuclear cells of cardiac recipients treated with mycophenolate mofetil. Transplantation 2006; 82:113-8. [PMID: 16861950 DOI: 10.1097/01.tp.0000225759.54343.23] [Citation(s) in RCA: 15] [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
BACKGROUND The objective of this study was to investigate purine nucleotide metabolism in peripheral blood mononuclear cells (PBMC) of cardiac transplant recipients switched from azathioprine to mycophenolate mofetil (MMF). METHODS Concentrations of guanosine 5'triphosphate (GTP) and adenosine 5'triphosphate (ATP), the activities of inosine monophosphate dehydrogenase (IMPDH), guanine phosphoribosyltransferase (GPRT), and hypoxanthine phosphoribosyltransferase (HPRT) were determined in PBMC of 27 cardiac transplant recipients before switch to MMF and 3, 6, and 12 months thereafter. RESULTS There was no difference in the activities of IMPDH and salvage pathway enzymes GPRT and HRPT as well as in intracellular GTP and ATP concentrations between the patients before switch to MMF and healthy controls. The GTP and ATP concentrations in PBMC of cardiac recipients did not change during the entire observation period. Although the MPA trough level remained similar, IMPDH activity declined from 897 to 316 pmol/10(6)PBMC/h 3 months after MMF onset, was almost completely inhibited after 6 months, and partially restored to 143 pmol/10(6)PBMC/h 12 months after switch to MMF. In contrast, GPRT activity increased after 3, 6, and 12 months of MMF therapy and HPRT activity 3 and 6 months after switch to MMF. CONCLUSIONS We demonstrated for the first time an induction of salvage pathway enzyme activities in PBMC under MMF therapy. This probably accounts for the maintenance of intracellular purine nucleotide pools and prevents the GTP depletion.
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Affiliation(s)
- Elena Devyatko
- Department of General Surgery and Transplantation, University Clinic of Surgery, Medical University Vienna, Vienna, Austria.
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Vethe NT, Mandla R, Line PD, Midtvedt K, Hartmann A, Bergan S. Inosine monophosphate dehydrogenase activity in renal allograft recipients during mycophenolate treatment. Scandinavian Journal of Clinical and Laboratory Investigation 2006; 66:31-44. [PMID: 16464785 DOI: 10.1080/00365510500420259] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Mycophenolic acid (MPA) exerts its immunosuppression by inhibiting inosine 5'-monophosphate dehydrogenase (IMPDH), depleting activated lymphocytes of guanine nucleotides and retarding their proliferation. An optimal strategy for monitoring has not been established for mycophenolate mofetil (MMF) in renal transplantation, and clinical investigations of the pharmacokinetic-pharmacodynamic relationship are warranted. MATERIAL AND METHODS Mycophenolic acid pharmacokinetics and whole blood cell IMPDH activity were investigated in two separate groups of renal allograft recipients. One group was studied within the 12-h dose interval, while the second group was examined by pre-dose samples pre-transplant and then repeatedly during 8 weeks post-transplant. RESULTS An inverse relationship between plasma MPA and IMPDH activity within the dose interval was demonstrated. Minimum IMPDH activity was a median 8 % of values pre-MMF dose, coinciding with the MPA peak. Six hours post-dose, IMPDH activity had returned to pre-dose values. Patients receiving MMF had a 4.5-fold higher pre-dose enzyme activity than transplanted patients without MMF. During the 8 weeks post-transplant, the median MPA trough concentration was fairly stable. Following an initial decrease during the first 4 days post-transplant, IMPDH activity gradually increased during the 40 days post-transplant, reaching 5-fold the pre-transplant values. CONCLUSIONS Provided that the changes in IMPDH activity in whole blood cells predict the clinical effect, these pharmacokinetic-pharmacodynamic findings may prove useful in the attempts to identify optimal timing and range for the monitoring of mycophenolate in renal transplantation. The question of whether MPA concentrations or measurements of IMPDH activity per se will be the optimal way of monitoring this immunosuppressant remains open and will only be answered by prospective clinical testing.
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Affiliation(s)
- N T Vethe
- Department of Surgery, Rikshospitalet University Hospital, NO-0027 Oslo, Norway
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Moosavi MA, Yazdanparast R, Sanati MH, Nejad AS. 3-Hydrogenkwadaphnin targets inosine 5'-monophosphate dehydrogenase and triggers post-G1 arrest apoptosis in human leukemia cell lines. Int J Biochem Cell Biol 2005; 37:2366-79. [PMID: 16084123 DOI: 10.1016/j.biocel.2005.04.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 04/10/2005] [Accepted: 04/26/2005] [Indexed: 12/01/2022]
Abstract
3-Hydrogenkwadaphnin (3-HK) is a recently characterized daphnane-type compound isolated from Dendrostellera lessertii with high anti-tumor activity in animal models. Herein, we report on time- and dose-dependent effects of this compound on growth, differentiation, IMPDH inhibition, cell cycle and apoptosis of a panel of human leukemia cell lines (HL-60, K562 and Molt4). The drug decreased the growth of leukemia cells in less than 24 h of treatment. However, longer exposure times and/or higher concentrations were required to promote cell apoptosis. Cell cycle analysis revealed the accumulation of cells in their G1 phase as early as 12 h after drug exposure but sub-G1 population was recorded after 24 h. Occurrence of apoptosis was constantly accompanied by morphological (staining with DNA-binding dyes) and biochemical (DNA fragments) variations among drug-treated cells. Despite these observations, non-activated normal human PBL were insensitive to the drug action. In addition, treatment of PHA-activated PBL, K562, Molt4 and HL-60 cells with a single dose of the drug for 24 h led to the inhibition of IMPDH activity by almost 37, 38, 44 and 50%, respectively. In contrast, no difference in IMPDH activities were seen between normal PBL and the drug treated PBL cells. Restoration of the depleted GTP concentration by exogenous addition of guanosine (25-50 microM) reversed the drug effects on cell growth, DNA fragmentation and apoptosis. Furthermore, the drug effects were potentiated by exogenous addition of hypoxanthine to the drug-treated cells. Reduction of the drug potency on the non-proliferative (retinoic acid treated) HL-60 cells by almost 40%, compared to the proliferative cells, clearly shows type II IMPDH as one of the main targets of the drug. These results suggest that 3-HK may be a powerful candidate for treatment of leukemia.
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Affiliation(s)
- Mohammad Amin Moosavi
- Institute of Biochemistry and Biophysics, P.O. Box 13145-1384, University of Tehran, Tehran, Iran
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Dubsky PC, Friedl J, Stift A, Bachleitner-Hofmann T, Jakesz R, Gnant MFX, Weigel G. Inosine 5'-monophosphate dehydrogenase inhibition by mycophenolic acid impairs maturation and function of dendritic cells. Clin Chim Acta 2005; 364:139-47. [PMID: 16051207 DOI: 10.1016/j.cccn.2005.05.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2005] [Revised: 05/12/2005] [Accepted: 05/13/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND The mechanism of action of mycophenolic acid (MPA) has been described as a blockade of inosine 5'-monophosphate dehydrogenase (IMPDH) and is thought to selectively influence T- and B-lymphocytes due to their strong dependency on guanine nucleotides synthesized via the de novo purine synthesis pathway. Recent evidence suggests MPA to affect antigen-presenting cells. METHODS Using CD14+ derived human dendritic cells (DC) we have investigated the effects of MPA on differentiation, maturation and function and studied intracellular nucleotide content and IMPDH activity. RESULTS GTP content and IMPDH activities of DC were strongly and dose-dependently decreased when MPA was present during the entire culture period or was added after the fifth (immature DC) or the seventh (mature DC) day of culture. Concurrent to low GTP levels, a dose-dependent reduction in the expression of CD80, CD86, CD40, CD54 and CD83 was seen which was accompanied by a decreased capacity of DC to stimulate T-cells. Our data for the first time shows a direct effect of MPA on the maturation and function of human CD14+ derived DC, indicates a role of IMPDH and a dependency on the de novo purine synthesis pathway.
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Affiliation(s)
- Peter C Dubsky
- Vienna Medical School, Department of Surgery, A-1090 Wien, Währinger Gürtel 18-20, Austria.
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Millán O, Brunet M, Martorell J, García F, Vidal E, Rojo I, Plana M, Gallart T, Pumarola T, Miró JM, Gatell JM. Pharmacokinetics and Pharmacodynamics of Low Dose Mycophenolate Mofetil in HIV-Infected Patients Treated with Abacavir, Efavirenz and Nelfinavir. Clin Pharmacokinet 2005; 44:525-38. [PMID: 15871638 DOI: 10.2165/00003088-200544050-00006] [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] [Indexed: 11/02/2022]
Abstract
BACKGROUND The use of mycophenolate mofetil in combination with highly active antiretroviral therapy (HAART) has been proposed in order to inhibit HIV replication. Due to the low doses involved, pharmacokinetic-pharmacodynamic monitoring is recommended. OBJECTIVE The aim of this study was to characterise the pharmacokinetic and pharmacodynamic monitoring of low doses of mycophenolate mofetil (0.25 g twice daily) in HIV-infected patients treated with HAART and after programmed discontinuation of HAART, in order to assess whether low doses of this immunosuppressive agent provide a biological effect. METHODS Mycophenolic acid (MPA) plasma levels (assessed by high-performance liquid chromatography) and the capacity of patients' sera to inhibit CEM cell line proliferation (assessed by (3)H-thymidine uptake) were measured post-dose at 0, 20, 40 minutes and 1, 2, 4, 6, 8, 10 and 12 hours in nine HIV-infected patients treated with a combination of abacavir, nelfinavir and efavirenz (HAART) and mycophenolate mofetil 0.25 g twice daily at days 7, 28, 120 and 150 (30 days without HAART) after the treatment initiation. A control group of eight patients was treated with HAART alone. RESULTS In the 35 post-dose curves analysed, no differences were found in MPA levels between days 7, 28, 120 and 150: area under the plasma concentration-time curve - mean value 15.3 mg . h/L, range 10.4-24.4 mg . h/L; minimum plasma concentration - mean value 0.60 mg/L, range 0.20-4.67 mg/L; maximum plasma concentration mean value 2.60 mg/L, range 0.94-7.98 mg/L. Pretreatment patients' sera did not inhibit CEM proliferation. Post-treatment patients' sera inhibited CEM proliferation to <40% in 25 of 35 curves at 0 hours (six of nine patients), in 34 of 35 curves at 1 hour, in 32 of 35 curves at 2 hours, in 22 of 35 curves at 4 hours, and in 8 of 35 curves at 12 hours. The MPA level versus CEM proliferation inhibition had a concentration that produces 50% of the maximum drug effect (EC(50)) of 0.33 mg/L. Viral load at day 150 was >200 copies/mL in all control patients and in three of nine patients receiving mycophenolate mofetil. These three patients were the only ones repeatedly unable to inhibit pre-dose CEM proliferation to <40%. CONCLUSIONS Mycophenolate mofetil pharmacokinetic profiles in HIV patients under HAART are not significantly different from those found in transplant patients. Sera from the majority of patients receiving low doses of mycophenolate mofetil inhibited lymphocyte proliferation during most of the inter-dose interval, despite low MPA plasma levels. For some patients, higher doses may be necessary: the capacity of sera to inhibit CEM proliferation may help to identify these patients.
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Affiliation(s)
- Olga Millán
- Servei Immunologia, Hospital Clínic, IDIBAPS, Universitat de Barcelona, Barcelona, Spain
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Goldsmith D, Carrey EA, Edbury S, Smolenski RT, Jagodzinski P, Simmonds HA. Mycophenolate mofetil, an inhibitor of inosine monophosphate dehydrogenase, causes a paradoxical elevation of GTP in erythrocytes of renal transplant patients. Clin Sci (Lond) 2004; 107:63-8. [PMID: 14723604 DOI: 10.1042/cs20030331] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2003] [Revised: 01/12/2004] [Accepted: 01/14/2004] [Indexed: 11/17/2022]
Abstract
The immunosuppressant MMF (mycophenolate mofetil) has increasingly replaced AZA (azathioprine) in renal transplantation. MMF is a prodrug of MPA (mycophenolic acid), which inhibits lymphocyte IMPDH (inosine monophosphate dehydrogenase), thereby drastically decreasing GTP concentrations essential to lymphocyte proliferation in vitro and in vivo. Erythrocyte GTP concentrations are commonly elevated in severe renal disease, but normalize following successful engraftment. Consequently, elevated GTP in renal transplant recipients might signal impending loss of immunosuppression and graft failure. In the present study, we compared erythrocyte nucleotides and plasma metabolites in two groups of 25 patients after renal transplantation, both receiving prednisolone and cyclosporin A, but one group receiving MMF and the other AZA. No patients had recent allograft biopsy evidence of rejection. Erythrocyte GTP concentrations at MMF commencement were 50.4+/-23.4 micromol/l. An increase occurred during the first 3 months after transplant when MMF was used de novo, stabilizing at 146.7+/-62.9 micromol/l after 4 months. This was significantly higher (P=2.5 x 10(-6)) than erythrocyte GTP (40.4+/-15.9 micromol/l) in the AZA group, which was essentially unchanged from values immediately after successful transplantation. The effect of MMF on erythrocyte GTP levels was reversible, since GTP levels fell when MMF therapy was terminated. The results demonstrate paradoxically high GTP concentrations in erythrocytes of renal transplant patients receiving MMF. MPA may stabilize reticulocyte IMPDH, allowing the protein to persist during erythropoiesis. This behaviour is in marked contrast with the decrease in GTP levels seen in white blood cells of patients on chronic MMF therapy.
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Affiliation(s)
- David Goldsmith
- Department of Renal Medicine, Guy's Hospital, London SE1 9RT, UK.
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Affiliation(s)
- E Anthony Jones
- Department of Gastrointestinal and Liver Diseases, Academic Medical Center, Amsterdam, The Netherlands.
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Glander P, Braun KP, Hambach P, Bauer S, Mai I, Roots I, Waiser J, Fritsche L, Neumayer HH, Budde K. Non-radioactive determination of inosine 5'-monophosphate dehydro-genase (IMPDH) in peripheral mononuclear cells. Clin Biochem 2001; 34:543-9. [PMID: 11738390 DOI: 10.1016/s0009-9120(01)00267-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND The immunosuppressive activity of mycophenolate mofetil (MMF) is based on the reversible inhibition of inosine 5'-monophosphate dehydrogenase (IMPDH) by mycophenolic acid (MPA). It was the aim of this study to develop a nonradioactive method for specific measurement of IMPDH activity in isolated peripheral mononuclear cells (MNC). METHODS The procedure is based on the incubation of lysed MNC with inosine 5'-monophosphate (IMP) followed by direct chromatographic determination of produced xanthosine 5'-monophosphate (XMP). IMPDH activity was measured in MNC of MMF-treated patients and nontreated volunteers. RESULTS The within-run (n = 10) and between-run (n = 20) coefficients of variation (CV) for IMPDH activity were < 8% and < 10%, respectively. IMPDH activity in 60 healthy volunteers (19-63 yr) ranged from 4.72 to 32.92 nmol/h/mg protein (mean = 18.39 +/- 6.24). The IC(50) for in vitro inhibition of IMPDH activity was about 2 to 3 microg/L. Application of a single dose of 1 g MMF in dialysis patients resulted in a significant inhibition (by 47-95%; p < 0.05) of IMPDH activity in lysed MNC. CONCLUSIONS The proposed assay specifically and reliably measures IMPDH activity in MNC. The procedure is applicable to evaluate pharmacodynamic activity in MMF-treated patients. The observed interindividual variability of IMPDH activity may reflect pharmacodynamic differences in MMF-treated patients.
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Affiliation(s)
- P Glander
- Department of Internal Medicine, Nephrology, University Medical Center Charité, Campus Mitte, Humboldt University, Schumannstr. 20/21, 10098 Berlin, Germany.
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18
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Bentley R. Mycophenolic Acid: a one hundred year odyssey from antibiotic to immunosuppressant. Chem Rev 2000; 100:3801-26. [PMID: 11749328 DOI: 10.1021/cr990097b] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R Bentley
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
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19
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Heinschink A, Raab M, Daxecker H, Griesmacher A, Müller MM. In vitro effects of mycophenolic acid on cell cycle and activation of human lymphocytes. Clin Chim Acta 2000; 300:23-8. [PMID: 10958860 DOI: 10.1016/s0009-8981(00)00297-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The immunosuppressant mycophenolic acid (MPA) selectively inhibits proliferation of T- and B-lymphocytes by blocking inosine 5'-monophosphate-dehydrogenase (IMPDH), the key enzyme for de-novo-synthesis of guanine nucleotides. In an in vitro study the effects of MPA on human peripheral blood lymphocyte activation markers and on cell cycle characteristics were investigated. Mononuclear cells from healthy volunteers were incubated with phytohaemagglutinin (PHA) and increasing doses of MPA. After 72 h incubation an aliquot of the cells was stained with propidium iodide and measured by FACS analyses to assess the DNA shape. In addition, the expression of the activation markers HLA-DR and CD25 on T- and B-lymphocytes was determined by flow cytometry analysis.PHA stimulation led to a significant increase of the S-phase of cell cycle. PHA stimulation clearly increased mean fluorescence intensity (MFI) of HLA-DR expression on B-lymphocytes. PHA stimulation also elevated the number of CD25 positive B-lymphocytes. Expression of HLA-DR on T-lymphocytes was not influenced by PHA, whereas CD25 expression and MFI significantly increased. All the observed PHA induced effects were reduced by co-incubation with increasing doses of MPA. The data presented show that in vitro the immunosuppressive effect of MPA can be demonstrated using FACS technology on a cellular level. MPA leads to an inhibition of cell cycle proliferation in peripheral blood lymphocytes.
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Affiliation(s)
- A Heinschink
- Institute of Laboratory Diagnostics and Ludwig Boltzmann Institute for Cardiothoracic Research, Kaiser Franz Josef Hospital, Kundratstrasse 3, A-1100, Vienna, Austria.
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20
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Millan O, Oppenheimer F, Brunet M, Vilardell J, Rojo I, Vives J, Martorell J. Assessment of Mycophenolic Acid-induced Immunosuppression: A New Approach. Clin Chem 2000. [DOI: 10.1093/clinchem/46.9.1376] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Background: Mycophenolic acid (MPA), a metabolite of mycophenolate mofetil (MMF), is an immunosuppressive agent that inhibits inosine monophosphate dehydrogenase (IMPDH), a key enzyme in the ex novo synthesis of GTP. We measured IMPDH activity in peripheral blood mononuclear cells (PBMCs) from MMF-treated patients to evaluate the efficacy of MMF in individual patients.
Methods: IMPDH activity was measured by 3H released from [2,8-3H]IMP that had been formed in the cells from added [2,8-3H]hypoxanthine in PBMCs of 35 renal transplant recipients treated with cyclosporin A and corticoids plus MMF: 2 g (n = 10), 1.5 g (n = 7), 1 g (n = 10), or 0 g (n = 8) per day. An alternative method, based on the capacity of the patients’ sera to inhibit spontaneous proliferation of the CEM cell line, was also analyzed.
Results: The IMPDH activity of PBMCs in transplanted patients was highly variable. For the method based on CEM cell line proliferation: (a) cell proliferation was inhibited only in MMF-treated patients; (b) there was a clear postdose increase in inhibition; (c) inhibition was not affected by other immunosuppressants in vitro or in vivo; (d) inhibition from predose to predose sample was correlated; and (e) when the MMF dosage was <20 mg · kg−1 · day−1, two groups of patients were identified, one that maintained a high inhibitory capacity in all dose intervals, and one with periods of low inhibitory capacity.
Conclusions: Measurement of the inhibition of CEM cell line proliferation by sera from MMF-treated patients may be useful for evaluating the relative efficacy of MMF treatment in individual patients, especially those receiving low doses of MMF.
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Affiliation(s)
| | - Federic Oppenheimer
- Unitat de Transplantament Renal, IDIBAPS, Hospital Clinic, C/Villarroel 170, 08036 Barcelona, Spain
| | | | - Jordi Vilardell
- Unitat de Transplantament Renal, IDIBAPS, Hospital Clinic, C/Villarroel 170, 08036 Barcelona, Spain
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21
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22
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Armbruster C, Robibaro B, Griesmacher A, Vorbach H. Endothelial cell compatibility of trovafloxacin and levofloxacin for intravenous use. J Antimicrob Chemother 2000; 45:533-5. [PMID: 10747834 DOI: 10.1093/jac/45.4.533] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Levofloxacin and trovafloxacin have excellent activity against a variety of Gram-positive and Gram-negative organisms resistant to the established agents. One local side-effect closely related to the use of parenteral fluoroquinolones is phlebitis. To evaluate the effect of trovafloxacin and levofloxacin on endothelial cell viability, intracellular levels of adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), guanosine 5'-triphosphate (GTP) and guanosine 5'-diphosphate (GDP) levels were measured using high-performance liquid chromatography. Trovafloxacin at concentrations of 2 and 1 mg/mL reduced the intracellular ATP content from 12.5 +/- 1.7 to 1.9 +/- 0.3 nmol/10(6) cells and 9.3 +/- 0.8 nmol/10(6) cells, respectively, within 60 min. In addition, ADP, GTP and GDP levels were extensively depleted. Levofloxacin at concentrations of 5 and 2.5 mg/mL led to a significant ATP decline from 12.5 +/- 1.7 to 2.3 +/- 0.2 nmol/10(6) cells and 10.3 +/- 0.9 nmol/10(6) cells, respectively, within 60 min. These data indicate that infusions of high doses of trovafloxacin or levofloxacin are not compatible with maintenance of endothelial cell function. Commercial preparations have to be diluted and should be administered into large veins.
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Affiliation(s)
- C Armbruster
- Second Medical Department/Pulmologisches Zentrum Vienna, Austria
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23
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Hastings KL. Assessment of immunosuppressant drug carcinogenicity: standard and alternative animal models. Hum Exp Toxicol 2000; 19:261-5. [PMID: 10918520 DOI: 10.1191/096032700678815837] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Drugs intended for use in preventing allograft rejection in transplant patients are likely to be administered chronically; thus, it is normally expected that sponsors would conduct nonclinical studies to determine the carcinogenic potential of candidate compounds. For pharmaceuticals other than biologic agents, this would mean that rodent carcinogenicity bioassays would be performed under most circumstances. Immunosuppressant drugs have presented unique challenges with respect to the issue of carcinogenicity bioassays. The pharmacological activity of therapeutic immunosuppressants is thought to make them highly likely to act as promoters/cocarcinogens, even in the absence of genotoxic activity. Thus, it is assumed that this class of drug would represent a carcinogenic hazard in the absence of confirmatory standard rodent bioassay data. In addition, rodents typically have been sensitive to the pharmacological/toxicological effects of immunosuppressants. It has proven to be difficult, therefore, to conduct life-time bioassays at doses reasonably equivalent to those that would be used clinically. For this and other reasons, alternative models might be more appropriate for risk assessment with this class of drugs.
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Affiliation(s)
- K L Hastings
- Division of Special Pathogen and Immunologic Drug Products, Center for Drug Evaluation and Research, US Food and Drug Administration, Rockville, Maryland 20857, USA
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24
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Valentin JF, Bruijn JA, Paul LC. Donor treatment with mycophenolate mofetil: protection against ischemia-reperfusion injury in the rat. Transplantation 2000; 69:344-50. [PMID: 10706040 DOI: 10.1097/00007890-200002150-00006] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Mycophenolic acid, the active metabolite of mycophenolate mofetil, inhibits the glycosylation of cell membrane glycoproteins. We hypothesized that impaired glycosylation of cell adhesion molecules on endothelial cells in vivo results in decreased susceptibility to inflammation or immunogenicity after allogeneic transplantation. METHODS The expression of mannose residues on cultured rat endothelial cells was examined after stimulation with interleukin 1 in the presence or absence of mycophenolic acid using labeled Galanthus nivalis agglutinin. The in vitro adhesion of blood leukocytes to heart tissue was examined using peripheral blood leukocytes of recipient origin and sections of donor heart tissue exposed to ischemia-reperfusion injury after pretreatment with vehicle or mycophenolic mofetil. (LEWxBN)F1 donor rats were treated with 20 or 60 mg/kg/day of mycophenolate mofetil for 1 or 2 weeks followed by transplantation of the heart into Lewis recipients after storage in heparin-containing normal saline for either 10 min at 4 degrees C or 120 min at room temperature. RESULTS Endothelial cells stimulated in vitro with interleukin 1 showed an increase in a population of strongly mannose-positive cells, which was prevented by the addition of mycophenolic acid during the culture. The in vitro adhesion of peripheral blood leukocytes to cardiac tissue sections exposed to prolonged storage and reperfusion was significantly less if the donor had been treated with mycophenolate mofetil. Treatment of cardiac graft donors with mycophenolate mofetil protected the graft against early graft failure after prolonged storage at room temperature, because the mean graft survival was 9.4+/-0.6 days for grafts that came from donors treated with mycophenolate mofetil versus 1.2+/-0.9 days (P<0.05) for grafts that came from vehicle-treated donors. Donor pretreatment with mycophenolate mofetil did not affect the survival time of heart grafts transplanted after 15 min of standard cold storage or the survival of grafts transplanted into presensitized recipients. CONCLUSION Donor treatment with mycophenolate mofetil protects cardiac grafts against primary nonfunction after prolonged tepid storage, which may be related to the inhibition of glycosylation of cell adhesion molecules involved in ischemia-reperfusion injury.
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Affiliation(s)
- J F Valentin
- Department of Medicine, University of Toronto at St. Michael's Hospital, Ontario, Canada
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25
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Seebacher G, Weigel G, Griesmacher A, Mallinger R, Zuckermann A, Grimm M, Laufer G. One and a half years of experience with mycophenolate mofetil (Cellcept) in cardiac transplantation: a prospective, randomized study. Transplant Proc 1999; 31:3291-3. [PMID: 10616480 DOI: 10.1016/s0041-1345(99)00729-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- G Seebacher
- Department of Cardiothoracic Surgery, University of Vienna, Austria
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26
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Vorbach H, Robibaro B, Armbruster C, Atteneder M, Reiter M, Hlousek M, Schaumann R, Georgopoulos A. Endothelial cell compatibility of clindamycin, gentamicin, ceftriaxone and teicoplanin in Bier's arterial arrest. J Antimicrob Chemother 1999; 44:275-7. [PMID: 10473235 DOI: 10.1093/jac/44.2.275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In patients with infected diabetic foot lesions, and gangrenous, peripheral, occlusive arterial disease, it is important to achieve high concentrations of antibiotics in the tissues, as the extent of amputation is often influenced by the presence of infection. Local transvenous pressure injection of antibiotics, in Bier's arterial arrest, allows high local tissue concentrations to be attained in the extremities. Information on the endothelial compatibility of antibiotics in high concentrations combined with the effect of reperfusion injury following tissue hypoxia is lacking. To evaluate the effect of clindamycin, gentamicin, ceftriaxone and teicoplanin injected in Bier's arterial arrest, on endothelial cells, an in-vitro model using human umbilical venous endothelial cells (HUVEC) has been devised. The intracellular levels of purine nucleotides, reflecting DNA/RNA synthesis, energy production and signal transduction of these cells were measured by means of high-performance liquid chromatography. Incubation of cells with 10 mg/mL clindamycin, gentamicin, ceftriaxone and teicoplanin for 20 min resulted in no significant decline of intracellular purines. Levels of purines obtained after exposure of the cells to 0.1 mmol/L hydrogen peroxide (H2O2), to simulate reperfusion injury, were not significantly different from those obtained from cells allowed to recover after antibiotic exposure. These findings indicate that the infusion of high doses of antibiotics, during Bier's arterial arrest, is compatible with maintenance of endothelial cell function, even in the presence of increased free radical activity, provided the exposure is limited to 20 min.
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Affiliation(s)
- H Vorbach
- Department of Internal Medicine II, Pulmonary Centre, University Hospital of Vienna, Austria.
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27
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Korecka M, Nikolic D, van Breemen RB, Shaw LM. The Apparent Inhibition of Inosine Monophosphate Dehydrogenase by Mycophenolic Acid Glucuronide Is Attributable to the Presence of Trace Quantities of Mycophenolic Acid. Clin Chem 1999. [DOI: 10.1093/clinchem/45.7.1047] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Background: Mycophenolic acid glucuronide, the primary metabolite of the immunosuppressive agent mycophenolic acid, affords weak inhibition of proliferating and resting lymphocytes and recombinant human inosine monophosphate dehydrogenase in comparison to the active drug. We evaluated the hypothesis that mycophenolic acid is a trace contaminant of the glucuronide metabolite preparation and that this accounts for the observed effects of mycophenolic acid glucuronide on human inosine monophosphate dehydrogenase catalytic activity both in lymphocytes and the pure enzyme.
Methods: We used negative ion electrospray HPLC-mass spectrometry (HPLC-MS) and HPLC-tandem MS (HPLC-MS-MS) to identify mycophenolic acid as a contaminant of mycophenolic acid glucuronide. Quantification of the mycophenolic acid contaminant was achieved using a negative ion electrospray HPLC-MS method in the selected-ion monitoring mode.
Results: Trace amounts of mycophenolic acid were detected and definitively identified in the mycophenolic acid glucuronide preparation by the HPLC-MS-MS analysis. In addition to having identical HPLC retention times, pure mycophenolic acid and the contaminant produced the following major fragments upon HPLC-MS-MS analysis: deprotonated molecular ion, m/z 319; and fragment ions, m/z 275, 243, 205, and 191 (the most abundant fragment ion). Using the negative ion electrospray HPLC-MS procedure in the selected-ion monitoring mode, the quantity of the contaminant mycophenolic acid was determined to be 0.312% ± 0.0184% on a molar basis.
Conclusion: These data provide strong support for the proposal that the apparent inhibition of the target enzyme inosine monophosphate dehydrogenase by mycophenolic acid glucuronide is attributable to the presence of trace amounts of contaminant mycophenolic acid.
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Affiliation(s)
- Magdalena Korecka
- Departments of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, PA 19104
| | - Dejan Nikolic
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60612
| | - Richard B van Breemen
- Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, IL 60612
| | - Leslie M Shaw
- Departments of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, PA 19104
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Abstract
In recent years, many new immunosuppressive drugs have been discovered and developed for clinical use in transplantation. This review focuses on those drugs (leflunomide, mycophenolate mofetil, sirolimus, tacrolimus) that have been shown to have immunosuppressive activity in patients. Different anti-interleukin-2 receptor antibodies are also reviewed as an example of a resurgence of development in the area of monoclonal antibodies. The price for reducing the incidence of allograft rejection by improved immunosuppression was thought to be a proportional increase in the incidence of infection and malignancy. Data from Phase III clinical trials of new immunosuppressants, however, show a statistically significant reduction in the incidence of acute rejection produced by these new drugs, which has not been accompanied by increases in infection and malignancy rates. The wide array of new drugs offers the opportunity to use combinations that block different pathways of immune activation while at the same time selecting drug combinations with nonoverlapping toxicity profiles so that doses of each single drug can be reduced below toxicity levels. The immunosuppressive therapy for patients can be tailored according to their individual needs.
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Affiliation(s)
- J F Gummert
- Department of Cardiothoracic Surgery, Stanford University Medical School, California 94305-5407, USA
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29
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Seebacher G, Weigel G, Wolner E, Mallinger R, Grimm M, Laufer G, El Menyawi I, Griesmacher A, Müller MM. A simple HPLC method for monitoring mycophenolic acid and its glucuronidated metabolite in transplant recipients. Clin Chem Lab Med 1999; 37:409-15. [PMID: 10369111 DOI: 10.1515/cclm.1999.067] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Mycophenolic acid (MPA) is nowadays in broad clinical use as a substitute for azathioprine. An immunoassay for MPA recently received approval for clinical applications. The high performance liquid chromatography (HPLC) assay for measuring MPA and its glucuronide conjugate (MPAG) we describe here is not only rapid and simple but also extremely sensitive at plasma levels obtained during standard immunosuppressive regimens. The determination of MPAG is possible without any change of the chromatographic conditions (detection wavelength of 214 nm, mobile phase: acetonitrile and 50 mmol/l o-phosphoric acid (50:50, V/V), run time: 15 min). The required equipment is a standard HPLC system including a simple UV-detector. Sample volume of 400 microl is required for both determinations. Detection limit is 0.25 micromol/l for MPA and 5 micromol/l for MPAG. Linearity is excellent for serial dilutions (0.5-25 micromol/l for MPA, 25-500 micromol/l for MPAG) and high accuracies favour the method described. More than 2000 plasma samples tested for MPA in patients after heart transplantation within one year and more than 500 samples for MPAG underline the clinical applicability of this assay.
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Affiliation(s)
- G Seebacher
- Department of Cardiothoracic Surgery, University Vienna, Austria
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30
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Schütz E, Shipkova M, Armstrong VW, Wieland E, Oellerich M. Identification of a Pharmacologically Active Metabolite of Mycophenolic Acid in Plasma of Transplant Recipients Treated with Mycophenolate Mofetil. Clin Chem 1999. [DOI: 10.1093/clinchem/45.3.419] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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31
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Nousari HC, Sragovich A, Kimyai-Asadi A, Orlinsky D, Anhalt GJ. Mycophenolate mofetil in autoimmune and inflammatory skin disorders. J Am Acad Dermatol 1999; 40:265-8. [PMID: 10025760 DOI: 10.1016/s0190-9622(99)70203-3] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Mycophenolate mofetil (MMF) has been widely used as an immunosuppressant in organ transplantation. MMF has recently been added to therapeutic regimens for skin disorders. Expanding the use of MMF in dermatology, we describe additional patients with autoimmune and inflammatory skin diseases, including 4 cases of pemphigus vulgaris, 1 case of pemphigus foliaceus, 1 case of perineal and metastatic cutaneous Crohn's disease, 1 case of bullous pemphigoid and psoriasis, and 1 case of psoriasis. Most of these patients had refractory disease or had developed significant side effects to conventional therapy, including azathioprine, methotrexate, prednisone, cyclosporine, acitretin, PUVA, UVB, and tacrolimus. MMF was effective and well tolerated in all these patients. The dosages of MMF ranged from 500 mg twice daily (for psoriasis and Crohn's disease) to 1250mg twice daily (for 3 of 4 patients with pemphigus vulgaris). MMF is an effective and relatively safe immunosuppressant in autoimmune and inflammatory skin diseases.
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Affiliation(s)
- H C Nousari
- Department of Dermatology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
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32
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Paul LC, Valentin JF, Bruijn JA, Zhang S. Donor treatment with mycophenolate mofetil protects against ischemia-reperfusion injury. Transplant Proc 1999; 31:1026. [PMID: 10083456 DOI: 10.1016/s0041-1345(98)01886-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- L C Paul
- Department of Nephrology, Leiden University Medical Centre, The Netherlands
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33
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Vorbach H, Weigel G, Robibaro B, Armbruster C, Schaumann R, Hlousek M, Reiter M, Griesmacher A, Georgopoulos A. Endothelial cell compatibility of clarithromycin for intravenous use. Clin Biochem 1998; 31:653-6. [PMID: 9876898 DOI: 10.1016/s0009-9120(98)00069-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Tolerance of intravenously applied clarithromycin has been tested on marginal ear veins of rabbits. Use of human umbilical venous endothelial cells (HUVEC) for testing antibiotic solutions for intravenous compatibility provides a valuable alternate model. DESIGN AND METHODS In order to evaluate the effect of clarithromycin on intracellular purines, reflecting cell viability, energy production, signal transduction and DNA/RNA synthesis, intracellular adenosine 5' triphosphate (ATP), adenosine 5' diphosphate (ADP), guanosine 5' triphosphate (GTP), and guanosine 5' diphosphate (GDP) levels were measured by means of high performance liquid chromatography (HPLC). RESULTS Incubation of cells with 2 mg/mL clarithromycin resulted in a rapid decrease of the intracellular ATP from 12.6 +/- 1.1 to 8.87 +/- 0.82 nmol/million cells or 1.5 +/- 0.6 nmol/million cells, after 20 or 60 min, respectively. In addition, ADP was extensively depleted. Purine nucleotide profiles were markedly different following exposure to 1 mg/mL clarithromycin. There was no significant decline of intracellular high energy phosphate levels after 20 min. CONCLUSION These results show that clarithromycin has a better endothelial compatibility if diluted to a final concentration of 1 mg/mL. These data are in line with our clinical observations that the occurrence of phlebitis could be minimized by diluting the manufacturers' preparation of clarithromycin to 1 mg/mL.
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Affiliation(s)
- H Vorbach
- Department of Internal Medicine II, University Hospital of Vienna, Austria
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34
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Shaw LM, Korecka M, Aradhye S, Grossman R, Barker C, Naji A, Brayman KL. Scientific principles for mycophenolic acid therapeutic drug monitoring. Transplant Proc 1998; 30:2234-6. [PMID: 9723454 DOI: 10.1016/s0041-1345(98)00603-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- L M Shaw
- Department of Pathology, University of Pennsylvania Medical Center, Philadelphia, USA
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35
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Shaw LM, Korecka M, van Breeman R, Nowak I, Brayman KL. Analysis, pharmacokinetics and therapeutic drug monitoring of mycophenolic acid. Clin Biochem 1998; 31:323-8. [PMID: 9721429 DOI: 10.1016/s0009-9120(98)00050-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- L M Shaw
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia 19104-4283, USA
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