Cyclosporine Concentrations Research Articles

Pharmacokinetics of Cyclosporine a Conversion From Twice-Daily Infusion to Oral Administration in Allogeneic Hematopoietic Stem Cell Transplantation

Twice-daily administration of cyclosporine A (CyA) has often been used for prophylaxis of acute graft versus host disease in allogeneic hematopoietic stem cell transplantation (allo-HSCT). But there have not been any reports that calculated the conversion ratio of the switch from twice-daily intravenous infusion to oral administration of CyA in adult patients. To establish the conversion ratio and the best strategy of twice-daily administration of CyA, the authors investigated the serial changes in the blood CyA concentration during the switch from twice-daily intravenous infusion to oral administration while maintaining high-peak concentration (over 1000 ng/mL) and calculated the bioavailability of Neoral, a micro emulsion cyclosporine, in 11 patients. All the patients underwent allo-HSCT with graft versus host disease prophylaxis consisting of CyA at a high-peak concentration of twice-daily infusion with short-term methotrexate and oral administration. Neoral was started at an oral dose, 2 times daily, at twice the latest dose of intravenous dose according to the bioavailability of healthy volunteers. Micafungin, a mild inhibitor of CYP3A4, was administered for prophylaxis against fungal infection. The total area under the concentration-time curve during oral administration (AUCpo) was nearly the same as AUC during intravenous infusion (AUCiv) (mean ± SD, 7206 ± 1557 ng·h·mL and 7783 ± 897.7 ng·h·mL, respectively). The bioavailability of Neoral, defined as F = AUCpo × DOSEiv/AUCiv × DOSEpo was 0.58 ± 0.15 (mean ± SD, range: 0.41-0.94). When patients were switched from twice-daily infusion to oral administration, the dose conversion ratio of 1:2 seemed to be appropriate. At that time, the target trough level of Neoral was nearly the same as that of the infusion.

Pharmacodynamic monitoring of immunosuppressive effects indicates reduced cyclosporine activity during telaprevir therapy

Drug interactions with immunosuppressive drugs are a mayor problem of protease inhibitor based antiviral triple therapy of Hepatitis C virus reinfection after liver transplantation. In this retrospective cohort study we analyzed biomarkers of immunosuppressive effects of cyclosporine A (CsA) by quantifying nuclear factor of activated T cells (NFAT)-regulated gene expression during telaprevir therapy in liver transplant patients. Further more, dose adjustment and blood concentrations of CsA as well as the clinical course were analyzed.

Pharmacodynamic monitoring of immunosuppressive effects indicates reduced cyclosporine activity during telaprevir therapy.

Drug interactions with immunosuppressive drugs are a major problem associated with protease inhibitor-based antiviral triple therapy for hepatitis C virus (HCV) reinfection after liver transplantation. In this retrospective cohort study, we analyzed biomarkers of the immunosuppressive effects of cyclosporine A (CSA) by quantifying nuclear factor of activated T cells (NFAT)-regulated gene expression during telaprevir (TVR) therapy in 5 liver transplant patients. Furthermore, dose adjustments and blood concentrations of CSA as well as the clinical course were analyzed. We observed a clear impact of TVR not only on doses and blood concentrations but also on the immunosuppressive effects of CSA. Despite apparently adequate CSA trough concentrations, the CSA peak concentration decreased to 68% (range = 44%-90%). This was associated with a 1.9-fold (1.6- to 4.1-fold) increase in the residual gene activity of NFAT-regulated genes, which indicated reduced immunosuppressive activity of CSA with TVR co-medication. The median dose of CSA was reduced to 25% (range = 16%-48%) and 31% (range = 22%-64%) after 1 and 2 weeks, respectively. The CSA drug clearance was reduced to 38.7% (range = 31.0%-49.4%). We report excellent antiviral efficacy. At the end of the observation period, all patients were HCV RNA-negative (1 patient at 18 weeks, 1 patient at 12 weeks, and 3 patients at 4 weeks after the end of therapy). Safety was acceptable, with mild acute rejection and reactivation of cytomegalovirus being the most serious adverse events. One patient with histologically proven recurrent cholestatic hepatitis before therapy underwent retransplantation during the course of antiviral therapy. In conclusion, the immunomonitoring of NFAT-regulated gene expression indicated reduced immunosuppressive activity of CSA during antiviral therapy with TVR in our cohort of liver transplant patients. Thus, the immunosuppressive effects of CSA may be overestimated if one is looking only at trough concentrations during co-medication with protease inhibitors or other strong cytochrome P450 3A inhibitors. Immunomonitoring of NFAT-regulated gene expression could, therefore, help to prevent overimmunosuppression or underimmunosuppression.

Taste-masked orodispersible tablets of cyclosporine self-nanoemulsion lyophilized with dry silica

The aim of the current study was to investigate the effects of formulation parameters on the disintegration, water absorption and dissolution characteristics of cyclosporine A (CyA) loaded self-emulsifying drug delivery system (SEDDS) in an orodispersible compacts. Its taste masking efficiency was also attempted using an electronic tongue. ODTs were prepared by freeze-drying liquid SEDDS and synthetic amorphous silica suspension followed by direct compression. The influences of the compression forces and super-disintegrant were evaluated to optimize tablet characteristics. The liquid SEDDS was characterized by vesicular size of 48.5 nm, polydispersity index of 0.95, turbidity of 40.7 NTU and rapid CyA dissolution and emulsification rate. The results of micrometric studies demonstrated an acceptable flow, hardness and friability to indicate good mechanical strength of ODTs. The interaction and Pareto charts demonstrated a greater effect of low compression force to increase the porosity and facilitate the disintegration rather than the deformation action of the super-disintegrant. Super-disintegrant level was the most important factor affecting the dissolution parameter followed by the compression force then their interaction effect. Moreover, as indicated by Euclidean distance values and discrimination indices, the unpalatable taste and aversion taste of CyA to stimuli were masked in its optimized SEDDS incorporated ODTs.

Cyclosporine A and tacrolimus reduce the amount of GLUT4 at the cell surface in human adipocytes: increased endocytosis as a potential mechanism for the diabetogenic effects of immunosuppressive agents.

Immunosuppressive agents are associated with profound metabolic side effects including new-onset diabetes and dyslipidemia after organ transplantation. To investigate the effects of cyclosporine A (CsA) and tacrolimus on glucose uptake and insulin signaling in human adipocytes and their impact on the regulation of cellular trafficking of the glucose transporter 4 (GLUT4). Isolated human adipocytes were incubated with therapeutic concentrations of either CsA or tacrolimus, and glucose uptake and expression of insulin signaling proteins were assessed. Furthermore, we studied effects of CsA and tacrolimus on the regulation of cellular trafficking of GLUT4 in differentiated human preadipocytes and L6 cells. CsA and tacrolimus had a concentration-dependent inhibitory effect on basal and insulin-stimulated (14)C-glucose uptake in adipocytes. Although phosphorylation at Tyr1146 of the insulin receptor was inhibited by tacrolimus, the phosphorylation and/or protein levels of the insulin signaling proteins IRS1/2, p85-PI3K, PKB, AS160, and mTORC1, as well as GLUT4 and GLUT1, were unchanged by CsA or tacrolimus. Furthermore, CsA and tacrolimus reduced the GLUT4 amount localized at the cell surface of differentiated human preadipocytes and L6 cells in the presence of insulin. This occurred by an increased rate of GLUT4 endocytosis, with no change in the exocytosis rate. These results suggest that therapeutic concentrations of CsA and tacrolimus can inhibit glucose uptake independent of insulin signaling by removing GLUT4 from the cell surface via an increased rate of endocytosis. This mechanism can contribute to the development of insulin resistance and diabetes associated with immunosuppressive therapy. In addition, it may provide novel pharmacological approaches for the treatment of diabetes.

Association of CYP3A4*18B and CYP3A5*3 polymorphism with cyclosporine-related liver injury in Chinese renal transplant recipients

The purpose of this study was to investigate the associations between CYP3A4*18B and CYP3A5*3 polymorphism and cyclosporine-related liver injuries in Chinese renal transplant recipients. We genotyped 339 renal transplant recipients treated with a triple immunosuppressive regimen including cyclosporine for CYP3A4*18B and CYP3A5*3 polymorphism using the polymerase chain reaction restriction fragment length polymorphism assay. The incidence of liver injury in the study population was 36.9% (125/339). At 1 month after transplantation, the trough concentration of cyclosporine (C0) in the group with CYP3A4*1/*1(GG alleles) was significantly higher than in the group with CYP3A4*18B/*1 8B(AA alleles) (p < 0.05). At 3 months after transplantation, the C0 in the group with CYP3A4*1/*1 and group with CYP3A4*1/*18B was markedly higher than in the group with CYP3A4*18B/*18B (p < 0.05). The GG genotypes of CYP3A4*18B were more common in the liver injury group compared with the control group (p < 0.05). Univariate logistic regression analysis showed that subjects carrying the GG genotypes had a 5.136- and 2.528-fold higher risk of developing cyclosporine-related liver injury than those with the AA and GA genotypes. When adjusted for sex, the risk of the CYP3A4*18B genotypes was OR = 4.969 for GG compared to AA (p = 0.030), and OR = 2.634 for GG compared to GA (p = 0.025). However, no association was observed between CYP3A5*3 polymorphisms with cyclosporine-related liver injury. These results suggested that the wild type of CYP3A4*18B is a risk factor for the development of cyclosporine- related liver injuries in Chinese renal transplant recipients.

Pharmacokinetic interaction study of ticagrelor and cyclosporine in healthy volunteers.

Patients with acute coronary syndrome and certain co-morbidities may receive ticagrelor, a reversibly binding P2Y(12) receptor antagonist, and cyclosporine, a commonly used immunosuppressant drug. This study assessed the potential pharmacokinetic drug-drug interaction between ticagrelor and cyclosporine. In this single-centre, open-label, three-treatment, three-period crossover study (NCT01504906), healthy volunteers (n = 26) randomly received each of three treatments: cyclosporine (600 mg single oral dose) plus ticagrelor (180 mg single oral dose); cyclosporine alone; ticagrelor alone. Treatments were separated by a washout period of ≥14 days. Plasma concentrations of ticagrelor and its active metabolite (AR-C124910XX) and blood concentrations of cyclosporine were analyzed, and pharmacokinetic parameters were calculated. Safety and tolerability were assessed. Compared with ticagrelor alone, the geometric least squares mean (LSM) ratio (90 % confidence interval [CI]) for the ticagrelor area under the plasma concentration-time curve from time zero to infinity (AUC(∞)) was 2.83 (2.63-3.06), and the maximum plasma concentration (C(max)) was 2.30 (2.06-2.58), in the presence of cyclosporine. Co-administration of cyclosporine with ticagrelor significantly increased AR-C124910XX AUC(∞) (1.33 [1.23-1.42]) and decreased C(max) (0.85 [0.76-0.94]). Ticagrelor had no effect on cyclosporine pharmacokinetic parameters, as the 90 % CIs of the LSM ratios were all within the 0.80-1.25 no-effect range. Co-administration of ticagrelor and cyclosporine was generally well tolerated. Co-administration of cyclosporine with ticagrelor increased exposure to ticagrelor and its active metabolite and had no effect on cyclosporine pharmacokinetic parameters. The magnitude of cyclosporine's effect on ticagrelor pharmacokinetics does not warrant dose adjustment of ticagrelor.

Semifluorinated alkanes as a liquid drug carrier system for topical ocular drug delivery

Semifluorinated alkanes (SFA, e.g. perfluorobutylpentane F4H5, perfluorohexyloctane F6H8) are inert, non-toxic fluids capable of dissolving lipophilic drugs. The aim of this study to assess the bioavailability and safety of SFAs as drug solvents for the topical ocular application of Cyclosporin A (CsA). A commercially available CsA formulation (Restasis®, 0.05% CsA in castor oil) was tested against two novel formulations of 0.05% CSA in (a) F4H5 containing Ethanol (0.5w/w%) and (b) F6H8 containing Ethanol (0.5w/w%) with 0.05% CsA. Formulations were tested on rabbit corneas cultured on an artificial anterior chamber with a constant flow of an aqueous humour supplement (Ex Vivo Eye Irritation Test (EVEIT) system). Anterior chamber fluids were sampled at multiple time points to analyse the CsA concentration following single and repeated application regimes by HPLC. Photographs of fluorescein sodium-stained corneas were recorded for corneal toxicity evaluation. The impact of the formulations on the integrity of the corneal barrier function was tested after drug application by fluorescein sodium corneal diffusion experiments. The influence on the corneal metabolism was evaluated by analysis of the metabolic markers glucose and lactate.Restasis® did not pass the corneal barrier after short term application, CsA in ethanolic F4H6 reached a maximum of 152.95ng/ml in anterior chamber fluid samples whilst CsA in ethanolic F6H8 reached a maximum of 15.12ng/ml. After repeated applications for 8h, Restasis® reached 21.07ng/ml compared to 247.62ng/ml and 174.5ng/ml for F4H5 and F6H8, respectively. No corneal toxicity was observed in following application of any of the formulations.In contrast to the commercially available castor oil-based formulation, CsA dissolved in SFAs reached therapeutic inner ocular concentrations after topical administration, possibly leading to the replacement of systemic applications of CsA for inflammatory ocular disease.

Resistance to cyclosporin A derives from mutations in hepatitis C virus nonstructural proteins

Cyclosporine A (CsA) is an immunosuppressive drug that targets cyclophilins, cellular cofactors that regulate the immune system. Replication of hepatitis C virus (HCV) is suppressed by CsA, but the molecular basis of this suppression is still not fully understood. To investigate this suppression, we cultured HCV replicon cells (Con1, HCV genotype 1b, FLR-N cell) in the presence of CsA and obtained nine CsA-resistant FLR-N cell lines. We determined full-length HCV sequences for all nine clones, and chose two (clones #6 and #7) of the nine clones that have high replication activity in the presence of CsA for further analysis. Both clones showed two consensus mutations, one in NS3 (T1280V) and the other in NS5A (D2292E). Characterization of various mutants indicated that the D2292E mutation conferred resistance to high concentrations of CsA (up to 2μM). In addition, the missense mutation T1280V contributed to the recovery of colony formation activity. The effects of these mutations are also evident in two established HCV replicon cell lines—HCV-RMT ([1], genotype 1a) and JFH1 (genotype 2a). Moreover, three other missense mutations in NS5A—D2303H, S2362G, and E2414K—enhanced the resistance to CsA conferred by D2292E; these double or all quadruple mutants could resist approximately 8- to 25-fold higher concentrations of CsA than could wild-type Con1. These four mutations, either as single or combinations, also made Con1 strain resistant to two other cyclophilin inhibitors, N-methyl-4-isoleucine-cyclosporin (NIM811) or Debio-025. Interestingly, the changes in IC50 values that resulted from each of these mutations were the lowest in the Debio-025-treated cells, indicating its highest resistant activity against the adaptive mutation.

Drug Interaction Between Oral Cyclosporine Modified and Iron.

To describe a recent case of suspected interaction between oral cyclosporine modified and iron. A 33-year-old man underwent urgent cardiac transplantation for refractory cardiogenic shock caused by acute myocarditis. The patient had persistently low levels of cyclosporine despite a dose increase of the drug after the change of administration route from intravenous to oral. Spacing the administration of cyclosporine modified from oral iron resolved the problem. This drug interaction was reported as "probable" as determined by a Drug Interaction Probability Scale score of 7. Using this scoring system, the patient experienced a probable drug interaction between cyclosporine and iron both administered orally, and we surmise that the mechanism is that iron physicochemically destabilizes the cyclosporine microemulsion when both are administered concurrently. This may be because of the interaction between cyclosporine microemulsion and iron because this cation can destabilize the immunosuppressant dosage form. Taking into account that joint administration of oral iron and cyclosporine modified can generate a physicochemical interaction that involves a decrease in the absorption of cyclosporine modified, we believe that it is necessary to recommend spacing administrations of both drugs as well as monitoring levels of cyclosporine in order to ensure optimal levels of immunosuppression.

Role of dendritic cells in the context of acute cellular rejection: Comparison between tacrolimus- or cyclosporine A-treated heart transplanted recipients

In the last years many studies have been designed to predict risk of acute rejection and to adapt the immunosuppressive therapy. The importance of dendritic cells (DCs) in the immune response, especially their role in tolerance is known. Thus, we investigated the influence of tacrolimus (TAC)-based and of cyclosporine A (CsA)-based immunosuppressive therapies on dendritic cells and the incidence of rejection in heart transplant recipients.Groups consisted of 14 CsA treated and 15 TAC treated patients. At different study time points (0, 3 and 6 months after study begin) peripheral blood from the patients was drawn to analyse (1) blood concentration of CsA or TAC (trough value) and (2) percentages of plasmacytoid and myeloid DC (p and mDC) subsets using flow cytometry. Histological rejection grading was performed of endomyocardial biopsies.TAC treated patients had significantly higher values of pDCs (CsA group 53.9%±13.0%; TAC group 67.5%±8.4%; p<0.05) and significantly lower values of mDCs than CsA treated patients (CsA group 58%±19.0%; TAC group 45.2%±10.7%; p<0.05). In general, HTx patients with rejection grade of ≥2 had significant lower values of pDCs (55.1%±16.2%) compared to patients without rejection (63.6%±10.5%; p<0.05). TAC-treated patients had significantly less rejections CsA-treated patients (CsA group 0.86±0.95; TAC group 0.2±0.4; p<0.05).Our results showed that HTx patients with high pDCs had a lower risk for rejection and that TAC-treated patients had higher pDCs values compared to CsA-treated patients. Future studies need to define individual pDC values to predict acute cellular rejection.

Once-daily oral administration of cyclosporine in a lung transplant patient with a history of renal toxicity of calcineurin inhibitors: Figure 1:

Cyclosporine is usually administered orally in two divided doses every 12 h in transplant patients. However, some patients have difficulty in achieving therapeutic levels after transplantation. In fact, cyclosporine is reportedly administered once daily in renal and liver transplantation cases, but not in lung transplantation cases. We report a patient with a history of calcineurin inhibitor-induced renal toxicity who successfully underwent living-donor lobar lung transplantation (LDLLT) with the novel immunosuppressive strategy of once-daily administration of cyclosporine. An 18-year old man with progressive respiratory insufficiency after bone marrow transplantation was referred to our hospital for lung transplantation. He had a history of renal toxicity due to calcineurin inhibitors. Based on his history of tacrolimus- and cyclosporine-induced renal toxicity, we decided to initiate basiliximab as induction therapy, followed by once-daily cyclosporine administration to obtain high enough blood cyclosporine concentrations at 2 h post-dose (C2) and lowered trough blood concentrations (C0) for protection of renal function as maintenance therapy. LDLLT was successfully performed, and the postoperative course was uneventful and free of rejection episodes. Cyclosporine dosing was adjusted with intensive therapeutic drug monitoring of blood cyclosporine levels. One year after LDLLT, the patient is alive and well with no problems with daily life activities.

Falsely elevated cyclosporin and tacrolimus concentrations over prolonged periods of time due to reversible adsorption to central venous catheters

Falsely elevated concentrations of immunosuppressants can be caused by reversible adsorption to central venous catheter (CVC) systems. If undetected, this may lead to dose reduction resulting in underdosage which may even entail graft-versus-host disease or organ rejection. We analyzed the adsorption and release for cyclosporine A (CsA) and tacrolimus (Tac) in vitro and in vivo. Four types of CVCs were examined in vitro: two made from polyurethane (PU), one from silicone and one from PU with an incorporated silver ion-based antimicrobial agent. All 26 CVCs analyzed in vitro showed significant reversible adsorption of CsA (n=13; p=0.001) and Tac (n=13; p=0.001, Wilcoxon signed rank test). Immediately after infusing the drugs, the mean concentrations of 6420ng/mL of CsA and 250ng/mL of Tac were measured. Flushing with NaCl lowered the drug release. Besides, blood samples of fifteen patients were taken simultaneously from all lumina of the CVC and via venipuncture. The samples from contaminated lumina showed the mean elevations by a factor of 11 for CsA (n=12) and 89 for Tac (n=3). Blood sampling for immunosuppressant monitoring should thus never be performed from lumina previously used for infusing the drug even after prolonged periods of time and extensive rinsing.

Favorable outcomes of tacrolimus compared with cyclosporine A for GVHD prophylaxis in HSCT for standard-risk hematological diseases

Although calcineurin inhibitors (CNIs) with short-term methotrexate (stMTX) constitute standard prophylaxis for graft-versus-host diseases (GVHD) in hematopoietic stem cell transplantations (HSCT), comparative efficacy of cyclosporine A (CsA) and tacrolimus (Tac) still remains unclear. We have altered GVHD prophylaxis for standard-risk hematological malignancies from CsA (target trough level, 500ng/mL) to Tac (15ng/mL) both with stMTX in May 2008, enabling us to compare the efficacy of CNIs with little selection biases. The cumulative incidence of acute and chronic GVHD was comparable for CsA and Tac. Among the GVHD low-risk patients who received stem cells from matched sibling donors or cord blood, the Tac arm had a trend for favorable control of grade III-IV acute GVHD (6.7 vs. 30.0%, p = 0.2), which may contribute to the significantly better overall survival (p = 0.048) and relapse-free survival (p = 0.043) in that group. Inadequate concentration of CNIs in early phase of HSCT affected the cumulative incidence of acute GVHD in the CsA but not in the Tac arm. There were no differences in the GVHD incidence and survival outcomes between CsA and Tac in the GVHD high-risk subgroup. This study underlies the significance of maintaining adequate CsA concentration in standard-risk HSCT.

Role of dendritic cells in the context of acute cellular rejection: Comparison between Tacrolimus- or Cyclosporine A-treated heart transplanted recipients.

Background: In the last years many studies have been designed to predict risk of acute rejection and to adapt the immunosuppressive therapy. The importance of dendritic cells (DCs) in the immune response, especially their role in tolerance is known. Thus, we investigated the influence of tacrolimus (TAC)-based and of cyclosporine A (CsA)-based immunosuppressive therapies on dendritic cells and the incidence of rejection in heart transplant recipients. Methods: Groups consisted of 14 CsA treated and 15 TAC treated patients. At different study time points (0, 3 and 6 months after study begin) peripheral blood from the patients was drawn to analyse (1) blood concentration of CsA or TAC (trough value) and (2) percentages of plasmacytoid and myeloid DC (p and mDC) subsets using flow cytometry. Histological rejection grading was performed of endomyocardial biopsies. Results: TAC treated patients had significantly higher values of pDCs (CsA group 53.9%±13.0%; TAC group 67.5%±8.4%; p<0.05) and significantly lower values of mDCs than CsA treated patients (CsA group 58%±19.0%; TAC group 45.2%±10.7%; p<0.05). In general, HTx patients with rejection grade of ≥2 had significant lower values of pDCs (55.1%±16.2%) compared to patients without rejection (63.6%±10.5%; p<0.05). TAC-treated patients had significantly less rejections CsA-treated patients (CsA group 0.86±0.95; TAC group 0.2±0.4; p<0.05). Conclusions: Our results showed that HTx patients with high pDCs had a lower risk for rejection and that TAC-treated patients had higher pDCs values compared to CsA-treated patients. Future studies need to define individual pDC values to predict acute cellular rejection. © 2014 International Clinical Cytometry Society

Close Monitoring of Cyclosporine A Concentration as a Means of Preventing Acute Graft-Versus-Host Disease in Allogeneic Stem Cell Recipients

The concentration of cyclosporine A (CsA) after allogeneic stem cell transplantation has been reported to be important in prevention of acute graft versus host disease (aGVHD). The target concentration and method of monitoring CsA concentration varies between transplant centers. More knowledge is needed to tailor the intensity of post transplant immunosuppression in relation to the risk of aGVHD, disease relapse and nephrotoxicity. We retrospectively analyzed data from 48 adult patients, who consecutively underwent myeloablative allogeneic stem cell transplantation in the years 2010 and 2011 at Rigshospitalet, Copenhagen. Transplant indications were AML (n=18), ALL (n=14), MDS (n=3), SAA (n=6), MM (n=2) and other (n=5). Whole blood concentration of CsA was measured once daily 8 hours after the administration of CsA. The median CsA concentration in weeks 1 to 4 was calculated, and patients were divided into two equally sized groups according to the median CsA concentration. Renal impairment was defined as doubling of serum creatinine during the first 28 days after transplantation. Comparison of groups with or without aGVHD grade II or more was done using the chi square test for categorical variables. Variables with a p<0.1 were further analyzed using multivariate logistic regression. Probability of developing aGVHD was calculated using the cumulative incidence procedure with death as competing event. The median concentrations of CsA in each of the first 4 weeks after transplantation are shown in figure 1. The proportion of patients with aGVHD grade II-IV was higher in those with CsA levels below the median 2 weeks after transplantation (p=0.019). This association was also found when assessing the cumulative incidence of aGVHD with death as competing event (p=0.012, figure 2), and furthermore remains significant in multivariate analysis after adjusting for donor relation, TBI and donor sex. All cases of aGVHD (n=20) occurred after 2 weeks from time of transplantation. CsA levels at week 1, 3 and 4 did not affect the risk of aGVHD. Importantly, CsA levels were not correlated with excess risk of developing renal impairment. No relation was found between CsA levels and death from relapse (P=0.73). This study indicates a close relationship between the concentration of CsA in the early post-transplant period and development of aGVHD grade II or more. Nephrotoxicity was not an obstacle for achieving higher concentrations of CsA. Therefore, close monitoring of the CsA concentration in the early transplant period is important in maintaining CsA within target concentration and thus preventing development of aGVHD. Target concentration of CsA early in the post transplant course should possibly be adjusted to higher levels than we observed in this series of patients.Figure 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

The Proton Pump Inhibitor Lansoprazole, but not Rabeprazole, the Increased Blood Concentrations of Calcineurin Inhibitors in Japanese Patients with Connective Tissue Diseases

Proton pump inhibitors (PPIs) are frequently coadministered with calcineurin inhibitors (CNIs) such as tacrolimus (TAC) and cyclosporin A (CSA), to treat or prevent upper gastrointestinal complications in Japanese patients with connective tissue diseases (CTDs). The coadministration of PPIs increases the blood concentration of TAC due to drug interaction. We retrospectively investigated the influence of the coadministration of PPIs and CNIs, as well as the influence of the cytochrome P450 (CYP) 2C19 gene polymorphism status, on the blood concentrations of TAC and CSA in patients with CTDs. Patients treated with TAC (n=35) or CSA (n=30) were enrolled and divided into three groups according to the PPI they received: lansoprazole (LPZ)-combined, rabeprazole (RPZ)-combined, and non-PPI-combined groups. We compared the blood concentrations of TAC or CSA and the incidences of adverse events among the three groups. CYP2C19 gene polymorphisms were also assessed to investigate its influence on the blood concentration of TAC or CSA. LPZ significantly increased the blood concentration of TAC 12 hours after TAC administration (p=0.030 and p=0.003, respectively) and CSA (p=0.047 and p=0.014, respectively) in comparison with RPZ and non-PPI-combined treatment. There were no significant differences in the mean CSA blood concentration two hours after administration in patients with or without PPI treatment, in the incidence of adverse events, or in the CYP2C19 gene polymorphism status among the three groups. Combining agents that are mainly metabolized by CYP3A4 such as LPZ elevates the blood concentrations of TAC and CSA, which could leading to adverse events.

Downregulation of CYP3A and P-Glycoprotein in the Secondary Inflammatory Response of Mice With Dextran Sulfate Sodium–Induced Colitis and Its Contribution to Cyclosporine A Blood Concentrations

CYP3A and P-glycoprotein (P-gp) play important roles in drug metabolism and excretion; however, their functions in pathological conditions remain unclear. Hepatobiliary abnormalities have been described in patients with ulcerative colitis, which may affect drug metabolism and excretion in the liver and small intestine. We examined the functions of CYP3A and P-gp in the liver and small intestine of mice with dextran sodium sulfate (DSS)-induced colitis. Up to day 7, inflammatory markers were significantly increased in the livers of DSS-treated mice, accompanied by decreased CYP3A. Additionally hepatobiliary transporters and Pregnane X receptor, which regulates the transcriptional activation of CYP3A, were reduced. Both CYP3A and P-gp were significantly decreased in the upper small intestine of DSS-treated mice on day 7. This was associated with the increased expression of inducible nitric oxide synthase, but not changes in nuclear receptor expression. On day 7 of DSS treatment, the concentrations of cyclosporine A (CsA), a substrate of both CYP3A and P-gp, were significantly higher than controls. These results indicated the existence of a second inflammatory response in the liver and upper small intestine of mice with DSS-induced colitis, and bioavailability of CsA was increased by the dysfunction of CYP3A and P-gp in these organs. [Supplementary Tables and Figure: available only at http://dx.doi.org/10.1254/jphs.13141FP]

Absorption of Transdermal and Oral Cyclosporine in Six Healthy Cats

Cyclosporine is commonly used orally to treat feline dermatoses. Due to difficulties administering oral medications, veterinarians sometimes prescribe compounded transdermal cyclosporine, despite studies showing limited absorption. The study objective was to compare cyclosporine blood concentrations after oral administration to concentrations after transdermal application of cyclosporine (prepared in pluronic lecithin organogel [PLO]) in six cats using a controlled, cross-over design with a 2 wk washout period. Cats were dosed at 5.1-7.4 mg/kg of cyclosporine q 24 hr either per os for 7 days or transdermally for 21 days. Cyclosporine blood concentrations were measured q 7 days and after the washout period. A monoclonal-based immunoassay (lower limit of quantitation was 25 ng/mL) was used. Median concentrations on the seventh day were 2,208 ng/mL (range, 1,357-3,419 ng/mL) 2 hr after orally administered cyclosporine and 37 ng/mL (range, 25-290 ng/mL) 2 hr after transdermally applied cyclosporine. Median concentration on day 21 was 58 ng/mL (range, 51-878 ng/mL) 2 hr after transdermally applied cyclosporine. Concentrations were quantifiable for transdermally applied cyclosporine, but considered therapeutic in only one of six cats. Based on those results, transdermally applied cyclosporine was not recommended in cats because of inconsistent absorption.

Cyclosporine A Protects RGC-5 Cells From Excitotoxic Cell Death

Cyclosporine A (CSA) is a widely used immunosuppressive drug. Furthermore, CSA showed neuroprotective properties in several neurological disorders. However, nearly no data exist regarding CSA and its possible neuroprotective effect on retinal ganglion cells (RGCs). RGC-5 cells were stressed with 10 mM glutamate for 24 hours with or without adding varying concentrations of CSA (1, 3, 6, or 9 μg/mL) to the medium. Cell viability and cell density were analyzed by MTS assay and crystal violet staining, respectively. Induction of apoptosis was determined through caspase 3/7 activity and Annexin V+/PI- flow cytometry. The incubation of RGC-5 cells with 10 mM glutamate for 24 hours induced a 3.1-fold and a 3.4-fold decrease in overall cell viability and cell density, respectively, compared with controls. The supplementation of 9 μg/mL CSA to 10 mM glutamate led to a 2.7-fold increase in overall cell viability (P<0.0005) and a 2.5-fold increase in cell density (P<0.0005) compared with RGC-5 cells treated only with 10 mM glutamate. Furthermore, the addition of 9 μg/mL CSA to 10 mM glutamate significantly reduced caspase 3/7 activity by 1.3-fold (P<0.0005) and the amount of Annexin V+/PI- cells by 2.8-fold compared with RGC-5 cells incubated with 10 mM glutamate alone. The neuroprotective effect of CSA dose-dependently decreased with lower concentrations. CSA can effectively protect RGC-5 cells against glutamate-induced excitotoxicity. Therefore, CSA should be tested in further experiments to evaluate its potential as a neuroprotective substance against RGC disorders.