Showing papers on "Mycophenolate published in 2016"

Mycophenolic Acid Pharmacokinetics and Relapse in Children with Steroid–Dependent Idiopathic Nephrotic Syndrome

Abstract: Background and objectives Therapeutic drug monitoring of mycophenolic acid can improve clinical outcome in organ transplantation and lupus, but data are scarce in idiopathic nephrotic syndrome. The aim of our study was to investigate whether mycophenolic acid pharmacokinetics are associated with disease control in children receiving mycophenolate mofetil for the treatment of steroid–dependent nephrotic syndrome. Design, setting, participants, & measurements This was a retrospective multicenter study including 95 children with steroid–dependent nephrotic syndrome treated with mycophenolate mofetil with or without steroids. Area under the concentration-time curve of mycophenolic acid was determined in all children on the basis of sampling times at 20, 60, and 180 minutes postdose, using Bayesian estimation. The association between a threshold value of the area under the concentration-time curve of mycophenolic acid and the relapse rate was assessed using a negative binomial model. Results In total, 140 areas under the concentration-time curve of mycophenolic acid were analyzed. The findings indicate individual dose adaptation in 53 patients (38%) to achieve an area under the concentration-time curve target of 30–60 mg·h/L. In a multivariable negative binomial model including sex, age at disease onset, time to start of mycophenolate mofetil, previous immunomodulatory treatment, and concomitant prednisone dose, a level of area under the concentration-time curve of mycophenolic acid >45 mg·h/L was significantly associated with a lower relapse rate (rate ratio, 0.65; 95% confidence interval, 0.46 to 0.89; P=0.01). Conclusions Therapeutic drug monitoring leading to individualized dosing may improve the efficacy of mycophenolate mofetil in steroid–dependent nephrotic syndrome. Additional prospective studies are warranted to determine the optimal target for area under the concentration-time curve of mycophenolic acid in this population.

Lack of cross-resistance to FF-10501, an inhibitor of inosine-5'-monophosphate dehydrogenase, in azacitidine-resistant cell lines selected from SKM-1 and MOLM-13 leukemia cell lines.

Abstract: Resistance to azacitidine is a major issue in the treatments of myelodysplastic syndrome and acute myeloid leukemia, and previous studies suggest that changes in drug metabolism are involved in the resistance. Therefore, drugs with mechanisms resistant or alternative to such metabolic changes have been desired for the treatment of resistant disease. We generated azacitidine-resistant cells derived from SKM-1 and MOLM-13 leukemia cell lines in vitro, analyzed the mechanisms, and examined the impact on the efficacy of other antimetabolic drugs. It appeared that the cell growth-inhibitory effect of azacitidine, expression levels of uridine-cytidine kinase 2, and the concentrations of azacitidine triphosphate were remarkably decreased in the resistant cells compared with those in parent cells. These results were consistent with previous observations that azacitidine resistance is derived from metabolic changes. Cross-resistance of greater than 10-fold (shift in IC50 value) was observed in azacitidine-resistant cells for decitabine and for cytarabine, but not for gemcitabine or the inosine-5'-monophosphate dehydrogenase (IMPDH) inhibitors FF-10501 and mycophenolate mofetil (cross-resistance to 5-fluorouracil was cell line dependent). The IMPDH inhibitors maintained their cell growth-inhibitory activities in the azacitidine-resistant cell lines, in which the levels of adenine phosphoribosyltransferase (which converts FF-10501 to its active form, FF-10501 ribosylmonophosphate [FF-10501RMP]), FF-10501RMP, and the target enzyme, IMPDH, were equivalent to those in the parent cell lines. These results suggest that an IMPDH inhibitor such as FF-10501 could be an alternative therapeutic treatment for leukemia patients with acquired resistance to azacitidine.

Corticosteroid-Sparing and Optimization of Mycophenolic Acid Exposure in Liver Transplant Recipients Receiving Mycophenolate Mofetil and Tacrolimus: A Randomized, Multicenter Study.

Abstract: BackgroundWe conducted a randomized multicenter open-label trial in de novo liver transplant recipients to assess the feasibility and potential benefit of a corticosteroid (CS)-free regimen coupled with tacrolimus (Tac) and dose-intensified mycophenolate mofetil (MMF) further adjusted individually.M

The Value of Monitoring the Serum Concentration of Mycophenolate Mofetil in Children with Steroid-Dependent/Frequent Relapsing Nephrotic Syndrome.

Abstract: Background: Mycophenolate mofetil (MMF) is an alternative treatment strategy in children with steroid sensitivity who have frequent relapses or steroid-dependent

In Vitro Influence of Mycophenolic Acid on Selected Parameters of Stimulated Peripheral Canine Lymphocytes.

Abstract: Mycophenolic acid (MPA) is an active metabolite of mycophenolate mofetil, a new immunosuppressive drug effective in the treatment of canine autoimmune diseases. The impact of MPA on immunity is ambiguous and its influence on the canine immune system is unknown. The aim of the study was to determine markers of changes in stimulated peripheral canine lymphocytes after treatment with MPA in vitro. Twenty nine healthy dogs were studied. Phenotypic and functional analysis of lymphocytes was performed on peripheral blood mononuclear cells cultured with mitogens and different MPA concentrations– 1 μM (10−3 mol/m3), 10 μM or 100 μM. Apoptotic cells were detected by Annexin V and 7-aminoactinomycin D (7-AAD). The expression of antigens (CD3, CD4, CD8, CD21, CD25, forkhead box P3 [FoxP3] and proliferating cell nuclear antigen [PCNA]) was assessed with monoclonal antibodies. The proliferation indices were analyzed in carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled cells. All analyses were performed using flow cytometry. The influence of MPA on apoptosis was dependent on the mechanism of cell activation and MPA concentration. MPA caused a decrease in the expression of lymphocyte surface antigens, CD3, CD8 and CD25. Its impact on the expression of CD4 and CD21 was negligible. Its negative influence on the expression of FoxP3 was dependent on cell stimulation. MPA inhibited lymphocyte proliferation. In conclusion, MPA inhibited the activity of stimulated canine lymphocytes by blocking lymphocyte activation and proliferation. The influence of MPA on the development of immune tolerance–expansion of Treg cells and lymphocyte apoptosis–was ambiguous and was dependent on the mechanism of cellular activation. The concentration that MPA reaches in the blood may lead to inhibition of the functions of the canine immune system. The applied panel of markers can be used for evaluation of the effects of immunosuppressive compounds in the dog.

Simultaneous determination of mycophenolate and its metabolite mycophenolate-7-o-glucuronide with an isocratic HPLC-UV-based method in human plasma and stability evaluation.

Abstract: Objectives: Mycophenolic acid (MPA) is an immunosuppressive agent which is commonly used in a fixed dose regime in solid organ transplantation. For clinical trials and therapeutic drug monitoring measuring plasma concentrations is necessary. Also, stability issues have to be addressed.Methods: We describe an isocratic, RP-based HPLC-UV method for simultaneous determination of MPA and its major metabolite Mycophenolic acid 7-o Glucuronide (MPAG) in human plasma. Pre-analytics included protein precipitation with acetonitrile. The method was validated according to EMA/FDA guidelines. Patient lithium-heparin plasma and blood was used for evaluation of short-term (72 hours at room temperature = RT) and long-term stability (2 years at −80 °C) without acidification.Results: Linearity was assessed in the concentration range of 0.5–40.0 μg/mL for MPA and 5.0–350.0 μg/mL for MPAG, respectively. For MPA coefficient of variation was <7.0% (lower limit of quantification = LLOQ: 10.8%), for MPAG <9.6% (LLOQ: 10...

Pharmacokinetic Analysis of Mycophenolate Mofetil and Enteric-Coated Mycophenolate Sodium in Calcineurin Inhibitor-Free Renal Transplant Recipients.

Abstract: Background Considerable interest exists in identifying calcineurin inhibitor (CNI)-free and thus, less-toxic immunosuppressive regimens, with mycophenolic acid (MPA)-based treatments being a suitable approach. Because pharmacokinetic analyses of MPA treatments in stable CNI-free renal transplant recipients are lacking, the authors aimed at comparing the steady-state pharmacokinetic characteristics of MPA in patients on stable treatment with mycophenolate mofetil (MMF) or enteric-coated mycophenolate sodium (EC-MPS) plus prednisone (≤5 mg/d). Methods In the prospective, nonrandomized, open-label study, patients with stable transplant function since ≥6 months received their routine single dose of either MMF (n = 12) or EC-MPS (n = 11). The MPA plasma concentration was recorded over 12 hours. Parameters assessed were predose MPA concentration (C0), postdose minimum and maximum concentration (Cmin and Cmax), time to maximum concentration (Tmax), and area under the concentration-time curve (AUC) for the 12-hours of exposure (AUC0-12). Results Baseline characteristics were comparable between both the groups. Consistent with enteric coating, the mean Tmax was significantly longer after the intake of EC-MPS compared with MMF (2.2 versus 0.8 hours; P = 0.0002). The exposure measures Cmin, Cmax, and AUC0-12 were not significantly different despite the higher mean MPA equivalent dose in patients receiving MMF compared with those receiving EC-MPS (85% versus 64% of the recommended single dose, respectively). Exposures as reflected by the median AUC0-12 values were 50.7 and 58.7 mg·h·L with MMF and EC-MPS, respectively (P = 0.340). All patients achieved a target AUC of >30 mg·h·L, and 61% had an AUC of >50 mg·h·L. Conclusions The study provides first results on the steady-state pharmacokinetics of the 2 MPA drugs in CNI-free immunosuppressant regimens. Pharmacokinetic parameters measured in this study under real-life conditions were comparable in patients receiving MMF or EC-MPS.

Structural Elucidation of Unknown Oxidative Degradation Products of Mycophenolate Mofetil Using LC-MS n

Abstract: Unknown degradation products of mycophenolate mofetil formed under oxidative stress conditions have been characterized via LC-MSn, using an RP-LC column (50 mm length, 2.1 mm i.d., 1.9 µm). The mobile phase consisted of 26 % acetonitrile and 74 % 9 mM ammonium acetate pH 5.87, the column temperature was set at 40 °C, and the flow rate of the mobile phase was 400 µL min−1. Four degradation products formed under the influence of 15 % hydrogen peroxide after an hour. Two of the degradation products had previously been identified as mycophenolic acid (m/z 321) and the N-oxide of mycophenolate mofetil (m/z 450). The other two unknown degradation products, denoted DP I (m/z 319) and DP II (m/z 466), were investigated in depth in order to identify their structures. The fragmentation patterns of DP I and DP II were established, analyzed, and compared to the fragmentation patterns of mycophenolate mofetil and the N-oxide of mycophenolate mofetil, which aided the elucidation of the structures of the unknown degradation products. The unknown degradation product DP I (m/z 319.2) was proposed to be an oxidized unsaturated mycophenolate aldehyde which also appeared as an ammonium adduct ion at m/z 336.3. The second unknown degradation product, DP II (m/z 466.3), was characterized as a doubly oxidized derivative of mycophenolate mofetil. A possible degradation pathway of mycophenolate mofetil under the influence of an oxidizing agent was also proposed.

Changes in the Immune System of Female Wistar Rats After Exposure to Immunosuppressive Treatment During Pregnancy

Abstract: This experimental study assessed the impact of medications frequently used after kidney transplantation on the immune system of pregnant female Wistar rats. The study evaluates medications, both approved and contraindicated during pregnancy in common therapeutic combinations. The study was conducted on 32 female Wistar rats, subjected to immunosuppressive regimens most commonly used in therapy of human kidney transplant recipients (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; and cyclosporine A, everolimus and prednisone). The animals received drugs by oral gavage 2 weeks before pregnancy and at 3 weeks of pregnancy. We found drug regimen-dependent differences in cytometry from spleen. Many subpopulations of lymphocytes were suppressed in rats treated with cyclosporine A, mycophenolate mofetil and prednisone and tacrolimus, mycophenolate mofetil and prednisone; the number of NK cells was increased in group of rats treated with cyclosporine A, everolimus and prednisone. We also found changes in histological examination of thymus and spleen of all treated dams. In cytokine assay, we noticed increasing levels of IL-17 with increasing doses of concanavalin A in control group and in group of dams treated with cyclosporine A, mycophenolate mofetil and prednisone. This increase was blocked in rats treated with tacrolimus, mycophenolate mofetil and prednisone and cyclosporine A, everolimus and prednisone. Qualitative, quantitative and morphological changes of immune system in pharmacologically immunosuppressed females have been observed. Thymus structure, spleen composition and splenocytes IL-17 production were mostly affected in drug regimen-dependent manner.

Reversible interstitial lung disease following treatment of atopic dermatitis with mycophenolate mofetil.

Abstract: A 37-year-old woman with severe atopic dermatitis, was commenced on mycophenolate mofetil (MMF). Over the preceding 5 years she had been managed in our unit and treated with phototherapy, ciclosporin and azathioprine. MMF was started at an initial dose of 500 mg daily, and increased to 1 g twice daily with good clinical effect. However, 18 months into this treatment, the patient was noted to be short of breath with a dry cough and pleuritic chest pain. Serum autoimmune screen, hepatitis and human immunodeficiency virus serology were unremarkable, as were routine haematology and biochemistry. Serum IgA was slightly elevated at 3.8 g/L (normal range 0.6–3.10 g/L) but IgG and IgM were within the normal range. The patient was treated with oral amoxicillin 1 g three times daily and clarithromycin 500 mg twice daily. High-resolution computed tomography (CT) of the chest revealed bilateral ground-glass opacification, consistent with interstitial lung disease (Fig. 1). CT–pulmonary angiography demonstrated no evidence of pulmonary embolism. The patient was too hypoxic to undergo bronchoscopy. A lung biopsy was therefore taken using video-assisted thoracoscopic surgery. Histological examination revealed diffuse homogeneous expansion of the interstitium, with an infiltrate of lymphocytes and histiocytes. No granulomas or viral inclusion bodies were seen, and stains for acid-fast bacilli and Pneumocystis jirovecii were negative. Tissue culture from the specimen was negative, as were blood culture and serum precipitins. Owing to a dry cough, sputum was unobtainable, despite physiotherapy. These findings were consistent with a cellular nonspecific interstitial pneumonia (NSIP), with MMF being the likely cause. MMF was immediately discontinued and the patient was commenced on prednisolone 40 mg daily, slowly reducing over 6 months. Her shortness of breath and exercise tolerance improved, along with the lung function test indices and the appearance on chest radiographs. She remains well and currently has a normal exercise tolerance. MMF is licensed in combination with other immunosuppressants for the prevention of rejection following allogeneic renal, heart and hepatic transplants. It is used off-licence as a steroid-sparing agent in the management of resistant atopic dermatitis, immunobullous disorders, connective tissue diseases, vasculitides and graft-versus-host disease. Rapid onset

Mycophenolic acid inhibits the phosphorylation of nuclear factor‑κB and Akt in renal tubular epithelial cells

Abstract: Renal tubulointerstitial injury induced by albumin overload is a critical stage during the progression of renal interstitial fibrosis and progression of chronic renal diseases. Inosine‑5'‑monophosphate dehydrogenase inhibitor mycophenolate mofetil (MMF), a pro‑drug of mycophenolic acid (MPA), is known to attenuate the progression of renal interstitial fibrosis; however, the underlying molecular mechanisms of the anti‑fibrotic effects of derivatives of MMF have not yet been studied. The present study assessed the effects of the MPA on renal tubular epithelial cells. Transforming growth factor beta 1 (TGF‑β1) has been indicated to have a central role in the underlying molecular mechanisms of renal fibrosis; furthermore, nuclear transcription factor‑κB (NF‑κB) is a transcription factor associated with the production of inflammatory cytokines, cell proliferation and apoptosis. In addition, the Akt signaling pathway has important roles in cell proliferation, differentiation, metabolism and apoptosis. The present study subjected the NRK52E rat kidney epithelial‑derived cell line to albumin overload, which resulted in an increase in TGF‑β1 production as well as phosphorylation of Akt and the binding activity of NF‑κB to the promoter region of the TGF‑β1 gene, which was, however, reduced following pre‑incubation of the cells with MPA. In addition, the effects of albumin were partially blocked by Ly294002, a specific inhibitor of Akt. In conclusion, the results of the present study suggested that MPA may exert its anti‑fibrotic effects by inhibiting the upregulation of TGF‑β1 and the activation of NF‑κB following albumin overload, which may be partly dependent on the Akt pathway.

Cytotoxic-Immunosuppressive Drug Treatment

Abstract: The use of alkylating agents, such as cyclophosphamide, has decreased in recent years because of concerns for ovarian toxicity. Their use is limited to patients with severe disease or disease refractory to inhibitors of nucleotide synthesis, such as mycophenolate acid or azathioprine. Because of a more favorable efficacy to toxicity ratio, mycophenolate acid is the drug of first choice in moderately severe lupus and can be used both as induction and maintenance therapy. Azathioprine is predominantly used as a steroid-sparing agent and as maintenance treatment. Calcineurin inhibitors like cyclosporine A and tacrolimus are used less often—predominantly as steroid-sparing agents or in patients with refractory disease—because of their renal toxicity. Patients on cytotoxic-immunosuppressive agents have increased risk for both common and opportunistic infections.

Usage of mycophenolate mofetil or salt thereof in preparing drug for resisting against influenza virus

Abstract: Disclosed is a usage of mycophenolate mofetil or pharmacologically acceptable salt thereof in preparing a drug for resisting against an influenza virus. Further disclosed is a usage of mycophenolate mofetil or pharmacologically acceptable salt thereof in preparing a drug for resisting against a drug-resistant phenotype influenza virus. The present invention also relates to a method for treating an influenza disease, comprising giving mycophenolate mofetil or pharmacologically acceptable salt thereof with an effective dose to an individual in need.

Changing of the guards: EMA warning on paternal use of mycophenolate mofetil: An unnecessary and insufficiently substantiated precaution.

Abstract: On October 23, 2015, the European Medicines Agency (EMA) issued a press release and subsequently recommended a change to the Summary of Product Characteristics (SmPC) for mycophenolate mofetil (MMF) (EMA, 2015a,b). This specifically addressed pregnancy related issues and the wording in SmPC sections 4.4 (Special warnings and precautions for use) and 4.6 (Pregnancy and lactation) (EMA, 2015b). A Direct Healthcare Professional Communication from the manufacturer followed the EMA press release (Roche, 2015). The new warnings and precautions now for the first time included a specific statement on paternal exposure before conception, stating that: “Sexually active men are recommended to use condoms during treatment and for at least 90 days after cessation of treatment” (EMA, 2015b). The rationale or supporting evidence behind these recommendations is not presented. The FDA SmPC does not hold a similar warning (FDA, 2016). These are very strong measures called upon by a regulatory authority that in effect mean that renal transplant recipients receiving MMF de facto cannot (or at the very least are strongly advised not to) father a child. Complying with EMA precautions, planned fatherhood would require substituting MMF with a different immunosuppressant drug such as azathioprine; this would not be without risk of organ rejection or serious adverse reactions. We believe these precautionary measures are unsubstantiated by any meaningful level of evidence, and we believe they introduce unnecessary concerns to clinicians and organ transplant recipients planning fatherhood as well as parents-to-be who conceived during paternal use of MMF. In our respective Drug and Teratology Information Services across three European countries, we have received many calls from confused clinicians and worried male renal transplant recipients planning fatherhood. These include questions about termination of pregnancy in case of paternal exposure. MMF is a well-documented human teratogen following first trimester in utero exposure, and appropriate precautions are suggested in the SmPC (Anderka et al., 2009; Hoeltzenbein et al., 2012; EMA, 2015b). The amount of human data relating to paternal exposure is moderate but quite reassuring, and does not suggest a level of risk that justifies the EMAwarnings and precautions. The United States National Transplantation Pregnancy Registry (NTPR) identified 205 pregnancies fathered by 152 transplant recipients who received MMF at the estimated time of conception (Jones et al., 2013). Among 194 live births, the rates of malformations, miscarriages and prematurity were 3.1% (no specific pattern), 6.8% and 11%, respectively. All of these observations are well with the expected range. The NTPR has since collected 70 additional cases with no signs of adverse fetal outcome (personal communication, Michael J. Moritz, NTPR, December 2015). A Norwegian study, reported 2463 male organ transplant recipients who fathered 4614 children before transplantation and 474 children after transplantation (Morken et al., 2015). Following organ transplantation, no increased risk was found for any adverse pregnancy outcomes compared with outcomes before organ transplantation or to general population estimates. While specific drug exposure data including MMF is not available from the paper, the majority of the transplant recipients will have received MMF. In vitro and animal data from the SmPC does not suggest a reproductive toxicity profile of MMF that justifies the current precautions (EMA, 2015b). Two genotoxicity assays (in vitro mouse lymphoma assay and in vivo mouse bone marrow micronucleus test) showed a weak potential of MMF to cause chromosomal aberrations at extremely high doses (300 mg/kg/day) in vivo in mice. Other in vitro tests for detection of gene mutation did not demonstrate genotoxic activity. MMF had no effect on fertility of male rats at oral doses up to 20 mg/kg/day. The systemic exposure at this dose represents 2 to 3 times the clinical exposure at the recommended clinical dose of 2 gram/day in renal transplant recipients (EMA, 2006; EMA, 2015b). There are no specific data on transfer of MMF in seminal fluid, but such transfer is unlikely to be of clinical relevance (Scialli et al., 2015). We conclude that the available data do not justify the new precautions to male transplant recipients issued by EMA, which are inconsistent with FDA recommendations. We believe that EMA must reconsider this particular change to the SmPC. We believe that EMA should present evidence that contradicts the available human data presented above rather than relying on speculative theoretical concerns of potential chromosomal damage or transfer of infinitesimal amounts of MMF through seminal fluid. In any case, it should be recommended that such suggested risk should be discussed on an individual level with a Published online 0 Month 2016 in Wiley Online Library (wileyonlinelibrary.com). Doi: 10.1002/bdra.23556

Mycophenolate mofetil: a new therapeutic option in dermatology

Abstract: Mycophenolic acid (MPA) was introduced in the 1970s as a treatment for psoriasis, it has since been reformulated as mycophenolate mofetil (MMF). With an improved side effect profile and enhanced bioavailability, MMF is a promising drug for immune-mediated skin diseases. It is currently approved for the prevention of organ rejection. Its list of dermatological indications continues to grow. As a noncompetitive inhibitor of inosine monophosphate dehydrogenase (IMPDH), MMF inhibits de novo purine synthesis. Its relative lack of hepatonephrotoxicity and perhaps low risk of carcinogenicity offer important therapeutic advantages. This new formulation showed enhanced bioavailability, tolerability and efficacy. No doubt case reports and case series of MMF therapy dominate the dermatologic literature; preliminary results are sufficiently promising to warrant larger, randomized clinical trials with this emerging therapy.

Improvement in Severe Mycophenolic Acid-associated Gastrointestinal Symptoms after Changing Enteric-coated Mycophenolate Sodium to Mizoribine in Renal Transplant Recipients: Two Case Reports.

Abstract: Clinical results point to a better gastrointestinal tolerability with enteric-coated mycophenolate sodium as compared to mycophenolate mofetil. However, some transplant recipients who are treated with enteric-coated mycophenolate sodium still experience gastrointestinal symptoms. We herein present two cases of renal transplant recipients with severe gastrointestinal symptoms who were switched from enteric-coated mycophenolate sodium to mizoribine, and the symptom reversal effects were evaluated using the Gastrointestinal Symptom Rating Scale. The results of this study showed a significant improvement in severe gastrointestinal symptoms in renal transplant recipients after converting from enteric-coated mycophenolate sodium to mizoribine.

Effect of Mycophenolate Mofetil on Diabetic Cardiomyopathy in db/db Mice.

Abstract: Recent studies have shown that chronic inflammation associated with the development and aggravation of type 2 diabetes mellitus is an important factor in the pathogenesis of diabetic macrovascular complications. Diabetic cardiomyopathy is characterized by functional and structural cardiac changes, most frequently myocardial fibrosis, including myocardial cell death and accumulation of extracellular matrix protein. Mycophenolate mofetil (MMF) was shown to ameliorate renal injury and prevent the development of nephropathy through anti-inflammatory mechanisms and attenuated podocyte apoptosis. A study using a carotid artery balloon injury model revealed that MMF greatly reduced intimal hyperplasia with decreased expression of TGF-b1 and collagen III. Mycophenolate mofetil prevented endothelial dysfunction through enhanced nitric oxide availability with improvement of endothelial nitric oxide synthase. The purpose of this study was to evaluate its effect on diabetic cardiomyopathy resulting from type 2 diabetes mellitus. Six-week-old male nondiabetic db/m and diabetic db/db mice were purchased from Jackson Laboratory (Sacramento, California, United States). All mice received a diet of rodent pellets (348 kcal/ 100 g) containing 5.5% crude fat and tap water ad libitum. Mycophenolate mofetil (Roche Pharma AG, Grenzach-Wyhlen, Germany) was incorporated into chow (Dooyeol Biotech, Seoul,

FRI0011 Mycophenolic Acid Synergizes with Lipopolysaccharide To Induce Interleukin (IL)-1β Release via Activation of Caspase-1 and Protects MRL/LPR Mice against Mortality Induced by Endotoxemia

Abstract: Background Mycophenolate mofetil (MMF), which inhibits T and B lymphocyte proliferation, is widely used to treat a variety of autoimmune diseases, such as systemic lupus erythematosus (SLE) and lupus nephritis (LN)[1]. Several studies have reported that in lupus nephritis induction therapy, MMF was more effective than intravenous cyclophosphamide (CYC) with a more safety profile [2], but the mechanism is still unclear. We are the first to show that mycophenolic acid (MPA), the active metabolite of MMF, in association with lipopolysaccharide (LPS), is able to promote the secretion of interleukin (IL)-1β[3], which contradicts the traditional conception that immunosuppressants inhibit the secretion of inflammatory factors. This may be related to patients who are treated with MMF exhibiting better clinical outcomes and a lower incidence of infection than patients treated with CYC. Objectives To investigate the mechanism and significance of MPA synergizing with LPS to induce IL-1β release. Methods Undiluted human blood, THP-1 cells or monocytes was stimulated with LPS and treated with or without MPA, and the supernatant IL-1β was detected by ELISA. The intracellular protein levels of THP-1cells were measured by Western blot. MRL/lpr mice were treated with saline, MMF or CYC for 2 months, then given an intraperitoneal (i.p.) injection of LPS or saline, the effect, survival and cytokines were observed. Results We found that MPA alone failed to induce IL-1β, whereas MPA synergized with LPS to increase IL-1β in a dose-dependent manner. MPA did not affect the intracellular p-p65 and pro-IL-1β protein levels. However, MPA augmented LPS-induced IL-1β release by activation of NLRP3 inflammasome (Fig. 1A,B). Ac-YVAD-cmk, the inhibitor of caspase-1, blocked the activation of caspase-1 and subsequently attenuated IL-1β secretion. Both MMF and CYC can prevent the development of LN in MRL/lpr mice. Only MMF can protect mice from mortality after LPS-induced septic shock (Fig. 1C). Conclusions MPA synergizes with LPS to induce IL-1β release depended on the activation of caspase-1 rather than the enhanced production of pro-IL-1β. MMF protects mice against mortality induced by LPS. These findings suggest that patients immunosupressed with MMF may have overly activated caspase-1, which causes a more sensitive host defense response to invading germs by promoting the induction of IL-1β. References Conti, F., et al., Mycophenolate mofetil in systemic lupus erythematosus: results from a retrospective study in a large monocentric cohort and review of the literature. Immunol Res, 2014. 60(2–3): p. 270–6. Ginzler, E.M., et al., Mycophenolate mofetil or intravenous cyclophosphamide for lupus nephritis. N Engl J Med, 2005. 353(21): p. 2219–28. Liu, Z., et al., Evaluating the effects of immunosuppressants on human immunity using cytokine profiles of whole blood. Cytokine, 2009. 45(2): p. 141–147. Acknowledgement This work was supported by National Natural Science Foundation of China(81501417). Xuechan Huang and Yi He contribute equally to this study. Corresponding author is Erwei Sun. Disclosure of Interest None declared

1-Alpha, 25-dihydroxyvitamin D3 alters the pharmacokinetics of mycophenolic acid in renal transplant recipients by regulating two extrahepatic UDP-glucuronosyltransferases 1A8 and 1A10

Abstract: Mycophenolic acid (MPA) is an important immunosuppressant broadly used in renal transplantation. However, the large inter-patient variability in mycophenolic acid (MPA) pharmacokinetics (PK) limits its use. We hypothesize that extrahepatic metabolism of MPA may have significant impact on MPA PK variability. Two intestinal UDP-glucuronosyltransferases 1A8 and 1A10 plays critical role in MPA metabolism. Both in silico and previous genome-wide analyses suggested that vitamin D (VD) may regulate intestinal UGT1A expression. We validated the VD response elements (VDREs) across the UGT1A locus with chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The impact of 1-alpha,25-dihydroxyvitamin D3 (D3) on UGT1A8 and UGT1A10 transcription and on MPA glucuronidation was tested in human intestinal cell lines LS180, Caco-2 and HCT-116. The correlation between transcription levels of VD receptor (VDR) and the two UGT genes were examined in human normal colorectal tissue samples (n = 73). PK alterations of MPA following the parent drug, mycophenolate mofetil (MMF), and D3 treatment was assessed among renal transplant recipients (n = 10). Our ChIP assay validate three VDREs which were further demonstrated as transcriptional enhancers with the luciferase assays. D3 treatment significantly increased transcription of both UGT genes as well as MPA glucuronidation in cells. The VDR mRNA level was highly correlated with that of both UGT1A8 and UGT1A10 in human colorectal tissue. D3 treatment in patients led to about 40% reduction in both AUC0-12 and Cmax while over 70% elevation of total clearance of MPA. Our study suggested a significant regulatory role of VD on MPA metabolism and PK via modulating extrahepatic UGT activity.