Concentrations Of CsA Research Articles

Applying machine learning to the pharmacokinetic modeling of cyclosporine in adult renal transplant recipients: a multi-method comparison.

Objective: The aim of this study was to identify the important factors affecting cyclosporine (CsA) blood concentration and estimate CsA concentration using seven different machine learning (ML) algorithms. We also assessed the predictability of established ML models and previously built population pharmacokinetic (popPK) model. Finally, the most suitable ML model and popPK model to guide precision dosing were determined. Methods: In total, 3,407 whole-blood trough and peak concentrations of CsA were obtained from 183 patients who underwent initial renal transplantation. These samples were divided into model-building and evaluation sets. The model-building set was analyzed using seven different ML algorithms. The effects of potential covariates were evaluated using the least absolute shrinkage and selection operator algorithms. A separate evaluation set was used to assess the ability of all models to predict CsA blood concentration. R squared (R 2) scores, median prediction error (MDPE), median absolute prediction error (MAPE), and the percentages of PE within 20% (F20) and 30% (F30) were calculated to assess the predictive performance of these models. In addition, previously built popPK model was included for comparison. Results: Sixteen variables were selected as important covariates. Among ML models, the predictive performance of nonlinear-based ML models was superior to that of linear regression (MDPE: 3.27%, MAPE: 34.21%, F20: 30.63%, F30: 45.03%, R 2 score: 0.68). The ML model built with the artificial neural network algorithm was considered the most suitable (MDPE: -0.039%, MAPE: 25.60%, F20: 39.35%, F30: 56.46%, R 2 score: 0.75). Its performance was superior to that of the previously built popPK model (MDPE: 5.26%, MAPE: 29.22%, F20: 33.94%, F30: 51.22%, R 2 score: 0.68). Furthermore, the application of the most suitable model and the popPK model in clinic showed that most dose regimen recommendations were reasonable. Conclusion: The performance of these ML models indicate that a nonlinear relationship for covariates may help to improve model predictability. These results might facilitate the application of ML models in clinic, especially for patients with unstable status or during initial dose optimization.

Drug-Drug Interactions With Cyclosporine in the Anti-Hepatitis C Viral PrOD Combination Regimen of Paritaprevir/Ritonavir-Ombitasvir and Dasabuvir in Organ Transplant Recipients With Severe Hepatic Fibrosis or Cirrhosis.

The clinical guidelines suggest that the dosing of cyclosporine (CsA), during combination therapy with paritaprevir/ritonavir-ombitasvir and dasabuvir (PrOD), would be only one-fifth of the pre-PrOD total daily dose to be administered once daily. However, this dosing may not be applicable to all patients depending on their clinical condition. This study focuses on the pharmacokinetic dynamics of PrOD with CsA in Asian organ transplant recipients with severe liver fibrosis or cirrhosis who undergo concurrent treatment with PrOD treatment and CsA. The efficacy and safety of PrOD treatment was also evaluated. Data from 7 patients obtained between January 2017 and September 2017 were retrospectively analyzed. Determinations of the blood concentrations of CsA were made, whether used as a single treatment or in combination therapy with PrOD. The combination regimen compared with CsA administered alone resulted in a 4.53-fold and 5.52-fold increase in the area under the concentration-time curve from time 0-12 hours (AUC0-12 h) of CsA on days 1 and 15, respectively. In addition, the maximal concentration, time to maximum concentration, and terminal phase elimination half-life (t1/2) of CsA were increased during the combined treatment of PrOD and CsA. The authors proposed reducing the CsA dosage during PrOD treatment to one-seventh of that of the pre-PrOD treatment of the total daily dose to maintain target CsA levels. All patients achieved sustained virologic responses at week 12. There were no episodes of serious adverse events or graft rejections observed. Although the combination with PrOD significantly affects the pharmacokinetics of CsA, it is effective and safe with regular monitoring of the CsA blood concentrations and appropriate CsA dose adjustment.

Development of a Population Pharmacokinetic Model for Cyclosporine from Therapeutic Drug Monitoring Data.

Aim To develop a population pharmacokinetic model for Uruguayan patients under treatment with cyclosporine (CsA) that can be applied to TDM. Patients and Methods. A total of 53 patients under treatment with CsA were included. 37 patients with at least one pharmacokinetic profile described with four samples were considered for model building, while the remaining 16 were considered for the assessments of predictive performances. Pharmacokinetic parameter estimation was performed using a nonlinear mixed effect modelling implemented in the Monolix® software (version 2019R1, Lixoft, France); meanwhile, simulations were performed in R v.3.6.0 with the mlxR package. Results A two-compartment model with a first-order disposition model including lag time was used as a structural model. The final model was internally validated using prediction corrected visual predictive check (pcVPC) and other graphical diagnostics. A total of 621 CsA steady-state concentrations were analyzed for model development. Population estimates for the absorption constant (ka) and lag time were 0.523 h−1 and 0.512 h, respectively; apparent clearance (CL/F) was 30.3 L/h (relative standard error [RSE] ± 8.25%) with an interindividual variability of 39.8% and interoccasion variability of 38.0%; meanwhile, apparent clearance of distribution (Q/F) was 17.0 L/h (RSE ± 12.1%) with and interindividual variability of 53.2%. The covariate analysis identified creatinine clearance (ClCrea) as an individual factor influencing the Cl of CsA. The predictive capacity of the population model was demonstrated to be effective since predictions made for new patients were accurate for C1 and C2 (MPPEs below 50%). Bayesian forecasting improved significantly in the second and third occasions. Conclusion A population pharmacokinetic model was developed to reasonably estimate the individual cyclosporine clearance for patients. Hence, it can be utilized to individualize CsA doses for prompt and adequate achievement of target blood concentrations of CsA.

Immunosuppressant quantification in intravenous microdialysate- towards novel quasi-continuous therapeutic drug monitoring in transplanted patients.

Therapeutic drug monitoring (TDM) plays a crucial role in personalized medicine. It helps clinicians to tailor drug dosage for optimized therapy through understanding the underlying complex pharmacokinetics and pharmacodynamics. Conventional, non-continuous TDM fails to provide real-time information, which is particularly important for the initial phase of immunosuppressant therapy, e.g., with cyclosporine (CsA) and mycophenolic acid (MPA). We analyzed the time course over 8h of total and free of immunosuppressive drug (CsA and MPA) concentrations measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 16 kidney transplant patients. Besides repeated blood sampling, intravenous microdialysis was used for continuous sampling. Free drug concentrations were determined from ultracentrifuged EDTA-plasma (UC) and compared with the drug concentrations in the respective microdialysate (µD). µDs were additionally analyzed for free CsA using a novel immunosensor chip integrated into a fluorescence detection platform. The potential of microdialysis coupled with an optical immunosensor for the TDM of immunosuppressants was assessed. Using LC-MS/MS, the free concentrations of CsA (fCsA) and MPA (fMPA) were detectable and the time courses of total and free CsA comparable. fCsA and fMPA and area-under-the-curves (AUCs) in µDs correlated well with those determined in UCs (r≥0.79 and r≥0.88, respectively). Moreover, fCsA in µDs measured with the immunosensor correlated clearly with those determined by LC-MS/MS (r=0.82). The new microdialysis-supported immunosensor allows real-time analysis of immunosuppressants and tailor-made dosing according to the AUC concept. It readily lends itself to future applications as minimally invasive and continuous near-patient TDM.

Effects of Citrus grandis peels on cyclosporin concentration and immune responses in mice

A previous study indicated that the coadministration of decoction of Citri Grandis Pericarpiurn (CGP), the peels of Citrus grandis (Rutaceae), significantly increased the blood level of cyclosporin (CsA) and resulted in acute intoxication of pigs. In this study, we aimed to measure the effects of CGP on the distribution of CsA in both lymphoid and non-lymphoid tissues as well as on the immune cell function in mice. Our results showed that coadministration of 3 g/kg CGP with CsA (Neoral®, 10 mg/kg) significantly decreased the concentrations of CsA in blood, liver, kidney and spleen by 37 %, 45 %, 46 % and 51 %, respectively, after a two week treatment. The decrease in CsA level correlated positively with the CGP dose. Pharmadynamically, coadministration of CGP restored the phagocytosis activity in blood decreased by CsA. Moreover, the nitric oxide production of activated macrophages and helper T cell type 1 (Th1) cytokines production suppressed by CsA were also reversed by the coadministration of CGP. In conclusion, coadministration of CGP significantly decreased the systemic exposure of CsA and resulted in higher macrophage and Th1 type activities than giving CsA alone in mice. Therefore, the combined use of CGP with CsA requires close monitoring clinically.

Higher Concentrations of Cyclosporine Metabolites in Liver Transplant Recipients With a History of Viral and Bacterial Infections

BackgroundInfection remains a serious clinical problem in liver transplant (LTX) recipients. A higher risk of infection is connected with immunosuppression therapy. The aim of the study was to assess the relationships between infections’ incidence and concentrations of cyclosporine (CsA) metabolites after LTX. MethodsForty-three liver transplant recipients receiving CsA were included in the study. With the use of liquid chromatography combined with tandem mass spectrometry, concentrations of CsA and its metabolites were measured: dihydroxylated cyclosporine metabolites (DiHCsA), trihydroxylated cyclosporine metabolites (TriHCsA), demethylcarboxylated cyclosporine metabolites (DemCarbCsA), AM1, AM9, and AM4N. The study protocol conformed with the Declaration of Helsinki. ResultsPatients with a history of Epstein-Barr virus (EBV) infection had higher DiHCsA, TriHCsA, DemCarbCsA, AM1/CsA, DiHCsA/CsA, TriHCsA/CsA i DemCarbCsA/CsA in comparison with group without such infection (P = .049, P = .037, P = .006, P = .018, P = .005, P = .027, and P = .026, respectively). LTX recipients with a history of all viral infections had higher DiHCsA, TriHCsA, DiHCsA/CsA, TriHCsA/CsA than patients without viral infections (P = .013, P = .021, P = .013, and P = .048, respectively). Multivariable analysis showed that AM1, DiHCsA, TriHCsA, DemCarbCsA, AM4N/CsA had positively influence on the incidence of all viral infections (β = 0.0302, P = .0328; β = 0.0699, P = .0453; β = 0.6781, P = .0382; β = 0.6767, P = .0414; and β = 0.8307, P = .0267, respectively). In multivariable analysis, patients with a history of all bacterial infections had higher AM1 and higher AM1/CsA in comparison with LTX recipients without such infections (β = 0.0118, P = .0279; and β = 0.0099, P = .036, respectively). ConclusionIn liver transplant recipients with a history of viral or bacterial infections higher concentrations of CsA metabolites were found. Possibly CsA metabolites could be used to assess the risk of infection in patients after liver transplantation. It should be confirmed in further investigations.

Topical cyclosporine A therapy for dry eye syndrome.

Topical cyclosporine A therapy for dry eye syndrome.

Ocular Distribution of Cyclosporine Following Topical Administration of OTX-101 in New Zealand White Rabbits.

Purpose: Evaluate the ocular distribution, tolerability, and systemic exposure of cyclosporine (CsA) in New Zealand white rabbits following topical administration of OTX-101, a novel, clear aqueous nanomicellar solution developed for the treatment of dry eye disease (DED).Methods: The study design included single- and repeat-dose phases. In the single-dose phase, rabbits received a single instillation of OTX-101 0.05% or CsA ophthalmic emulsion 0.05% (Restasis®; Allergan, Irvine, CA) as a comparator. In the repeat-dosing phase, OTX-101 (0.01%, 0.05%, or 0.1% CsA) or comparator was instilled 4 times per day for 7 days. Samples collected included whole blood, tears, and ocular tissues/fluids (aqueous humor, choroid-retina, conjunctiva, cornea, superior eyelid, third eyelid, iris/ciliary body, lacrimal gland, lens, sclera, and vitreous humor). CsA concentrations were analyzed using liquid chromatography-tandem mass spectrometry.Results: Analysis included samples from 112 rabbits. The highest concentration of CsA following a single OTX-101 0.05% instillation occurred in the third eyelid (Cmax = 1,200 ng/g). Concentrations of CsA in the cornea and superior bulbar conjunctiva increased in a dose-related manner following repeated administration of OTX-101 formulations; Cmax [Tmax (h)] for cornea was 1,543 ng/g (6.50), 5,410 ng/g (7.0), and 8,123 ng/g (6.50), for 0.01%, 0.05%, and 0.1% CsA concentrations, respectively; for superior bulbar conjunctiva was 726 ng/g (6.50), 1,468 ng/g (6.50), and 2,080 ng/g (6.25), respectively.Conclusions: OTX-101 topical ophthalmic instillation resulted in extensive distribution of CsA in ocular tissues, particularly in target tissues for DED (cornea and conjunctiva), while systemic exposure was negligible.

Diltiazem aggravates testicular function impairment induced by cyclosporine A or tacrolimus in unilateral nephrectomised rats.

The aim of this study was to elucidate the reproductive toxicity of the coadministration of diltiazem and cyclosporine A or tacrolimus. Testicular development, semen quality, sex hormones and testicular tissues were assessed in unilateral nephrectomised (UN) rats, including the control group, UN group, UN+CsA group, UN+FK506 group, UN+Rapa group, UN+CsA+Dil group and UN+FK506+Dil group. The testicular coefficient, the sperm number and the sperm motility were lower in the treatment groups (except UN+FK506) than in the control and UN groups (all p<0.05). The lowest sperm number and motility were identified in the UN+CsA+Dil group, followed by the UN+CsA group. The proportion of abnormal sperm was higher in the UN+CsA and UN+CsA+Dil groups than in the control and UN groups, respectively (p<0.05). The plasma concentrations of sex hormones were changed in the treatment groups. Dil can increase the blood concentrations of CsA and FK506 (◇p<0.05, ◆p<0.05). Therapeutic doses of these agents induced morphological changes in the testicular tissue and ultrastructural changes in the testosterone, mesenchymal cells and supporting cells. Our present study suggests that Dil can increase the testicular toxicity of CNIs (calcineurin inhibitors, including CsA and FK506) by enhancing the plasma concentrations of CNIs.

Switching Immunosuppression From Cyclosporine to Tacrolimus in Kidney Transplant Recipients Based on CYP3A5 Genotyping.

Kidney transplant recipients on long-term cyclosporine (CsA) therapy may develop multiple adverse drug events, and immunosuppression conversion from CsA to tacrolimus (Tac) is an option. Genetic variations, especially cytochrome P450 (CYP) 3A5*3, affects Tac dosing. However, little information is available to guide the conversion with regards to patients' pharmacogenomics. We aimed to investigate whether CYP3A5, CYP3A4, and ABCB1 genotyping could contribute to a more precise and individualized initial dosing of Tac at the time of immunosuppressant conversion. Genotypes of 5 candidate genes (CYP3A5*3, CYP3A4*1G, ABCB1C1236T, ABCB1C3435T, and ABCB1G2677T/A) were investigated by polymerase chain reaction and restriction fragment-length polymorphism methods in 46 adult kidney transplant recipients requiring immunosuppressant conversion from CsA to TAC. Associations between these functional genetic polymorphisms and the dose-adjusted trough concentrations of CsA and Tac were evaluated, retrospectively. Based on the linear regression analysis, CYP3A5 expressers (*1/*1 and *1/*3) had lower Tac dose-adjusted trough concentrations on days 7, 14, 21, and 28, and they required 1.40- to 1.75-fold higher daily dose to reach the target concentration compared with nonexpressers (*3/*3) on day 28 [0.07 (0.06-0.09) mg/kg/d versus 0.05 (0.02-0.06) mg/kg/d, P = 0.001]. CYP3A4*1G or ABCB1 genetic polymorphisms had no effect on the Tac dose-adjusted trough concentrations. Our preliminary study supports the use of CYP3A5 genotyping to guide the initial dosing of Tac when converting the immunosuppression therapy from CsA to Tac.

Lack of a Significant Pharmacokinetic Interaction between Letermovir and Calcineurin Inhibitors in Allogeneic HCT Recipients

Background Letermovir (LET) is approved for the prophylaxis of cytomegalovirus (CMV) in allogeneic hematopoietic cell transplantation (allo-HCT) patients. LET is a weak-moderate CYP3A4 inhibitor, which may impact calcineurin inhibitor (CNI) levels. In the phase 1 trial, LET caused an increase in maximum plasma concentrations (Cmax) of CSA and tacrolimus by 37% and 70%, respectively. There are no data to correlate how the Cmax increase in the presence of LET may affect CNI trough levels. Methods A retrospective review was conducted to evaluate the effect of LET on CNI trough levels and determine if empiric dose adjustments are needed. Patients ≥ 18 years were included if they received an allo-HCT with a CNI from February to June 2018 and received LET 480 mg daily or 240mg daily for tacrolimus- or CSA-based GVHD prophylaxis, respectively. The primary endpoint was percent change in concentration to dose (C/D) ratio over the 7-day period after initiation of LET. The C/D ratio allows for an analysis of the effect on trough levels at any given dose, which we would expect to rise upon initiation of LET due to CYP inhibition. LET reaches steady state in 36-60 hours; therefore, C/D percent changes were evaluated both from baseline to 4 days post-LET and from day 4 to day 7. Results Thirty-four patients (median age 53, range 24-75) were included in the analysis, with 24 (70.6%) patients receiving a tacrolimus-based graft-versus-host disease (GVHD) prophylaxis and 10 (29.4%) patients receiving CSA-based GVHD prophylaxis. There were 8 (24%) umbilical cord blood transplants, 10 (29%) haploidentical HCTs, and 16 (47%) conventional HCTs, with 14 patients (41%) receiving myeloablative conditioning. LET was initiated on a median of day 7 (range 6-30) post-HCT, and 23 patients (68%) received the drug orally. In the 10 patients who received CSA, there was an average of 3.8 (range 1-6) dose changes over 7 days. From baseline to 4 days post-LET, the mean percent change in C/D ratio was +15.9%, with a subsequent -10.0% change in C/D ratio from day 4 to day 7. In the 24 patients who received tacrolimus, there was an average of 2.2 (range 0-5) dose changes over 7 days. From baseline to 4 days post-LET, the mean percent change in C/D ratio was +20.4%, with a subsequent -18.9% change in C/D ratio from day 4 to day 7. Days 0 to 7 trough levels for all patients are displayed in Figures 1 and 2. Conclusion An empiric dose reduction in CNIs upon initiation of LET does not appear to be warranted based on this pilot study. An increase in trough levels is seen within 4 days after initiation of LET; however, the increase seems marginal and is compensated for by adjusting doses based on levels, which is the standard of care. Larger studies are needed to assess additional factors that may affect this drug-drug interaction.

Hydroxylated, Hydroxymethylated, Dihydroxylated, and Trihydroxylated Cyclosporine Metabolites Can Be Nephrotoxic in Kidney Transplant Recipients

BackgroundCyclosporine (CsA) is an immunosuppressive agent whose use is associated with adverse effects, including nephrotoxicity. There are reports indicating that some CsA metabolites may contribute to these effects. This study was aimed at evaluation of CsA metabolites and correlating them with kidney function. MethodsIn 62 kidney transplant recipients (41.9% women; overall mean age, 48.44 ± 11.75 years), concentrations of CsA and 4 groups of metabolites were assessed: hydroxylated (HCsA), hydroxymethylated (HMCsA), dihydroxylated (DHCsA), and trihydroxylated (THCsA). The results were normalized with the use of the metabolite-to-parent drug ratio, and results were linked with estimated glomerular filtration rate (eGFR) at 3 months before (−3M), point zero (0M), and after 3 (+3M) and 12 (+12M) months. ResultsMultivariate analysis demonstrated the negative influence of eGFR −3M on HMCsA/CsA (β = −0.266; P < .05) and the negative influence of HCsA/CsA, HMCsA/CsA, DHCsA/CsA, and THCsA/CsA on eGFR +3M (β = −0.339, β = 0.396, β = −0.314, and β = −0.321, respectively; P < .005) and eGFR +12M (β = −0.363, β = −0.316, β = −0.267, and β = −0.312, respectively; P < .05). We did not detect such influence of CsA concentrations on eGFR +3M and +12M. The THCsA/CsA receiver operating characteristic cutoff value for prediction of improvement of kidney function at +12M was 0.143. ConclusionsOur results suggest that impaired function of the transplanted kidney affects the accumulation of HMCsA. It is possible that the increased metabolite (HCsA, HMCsA, DHCsA, and THCsA) to cyclosporine ratio could influence or could be a marker of cyclosporine nephrotoxicity. In this context, the most promising marker seems to be THCsA/CsA ratio, but its real significance requires further studies to determine.

The study of cyclosporin A modified intraocular lens preventing posterior capsular opacification in rabbit eyes

To investigate the safety and efficacy of cyclosporine A sustained release from modified intraocular lens for preventing posterior capsular opacification (PCO) in rabbit eyes. Forty-five New Zealand albino rabbits undergoing phacoemulsification in their right eyes were randomly and equally divided into three groups. Group A had implanted original IOL, group B had implanted PLGA-IOL(IOL coated with polylactide-glycoli acid), and group C had implanted CsA-PLGA-IOL (CsA loaded PLGA-IOL). All the 45 eyes were examined by a slit-lamp microscope. The intraocular pressures were recorded. Anterior chamber flare and aqueous humor cells were graded at different time point after surgery. The concentrations of CsA in the aqueous humor and blood were determined by high performance liquid chromatography. Anterior segment tissue was histologically examined. Wet posterior capsules were weighed. PCO was graded 6 months later. The mean concentrations of CsA in group C at 2 h,1 d,3 d,7 d,14 d,30 d,60 d after operation were (11.47±2.42) mg/L, (10.30±2.15) mg/L, (6.71±1.45) mg/L, (4.81±1.16) mg/L, (6.11±0.84) mg/L, (2.53±0.77) mg/L, (0.86±0.28) mg/L. The concentrations of CsA in blood were undetectable. During the early days after operation, the reactions of the anterior chamber in group A and B were more severe than group C. The initial appearance of PCO in group C was much later than in the other two groups, and the grade of PCO in group C was much lower than the other two groups. The mean weights of wet posterior capsules in group A(312.86±52.91) mg and B(310.64±62.42) mg were much heavier than that of group C(56.93 ± 24.24) mg. Histological observation showed that there was remarkably less accumulation of lens materials on the posterior capsules in group C than in the other two groups. No toxic actions were found in intraocular tissues in group C. Our study suggested that Cyclosporin A modified intraocular lens could effectively and safely prevent the formation and development of posterior capsular opacification in rabbit eyes for a relatively long term.

Clinically-relevant cyclosporin and rapamycin concentrations enhance regulatory T cell function to a similar extent but with different mechanisms: an in-vitro study in healthy humans.

Evidence indicates that regulatory T cells (Tregs) are profoundly involved in promoting allograft tolerance after organ transplantation. Since a successful transplantation currently still requires a long-term immunosuppressive treatment, clarifying the specific impact of these drugs on Tregs may be of high clinical relevance. Conflicting results arise from the literature, particularly as concerns cyclosporine (CsA). The specific aim of this work was to evaluate in-vitro the direct effects of clinically-relevant drug concentrations of three widely used immunosuppressive drugs, i.e. CsA, rapamycin (RAPA) and mycophenolic acid (MPA), on Treg activity, number and forkhead/winged helix transcription factor (FoxP3) expression in humans. Tregs (CD4(+)CD25(+)) isolated from healthy donors were cultured in the presence of different concentrations of CsA, RAPA or MPA. The suppressive activity of Tregs was evaluated in mixed lymphocyte reactions with CD4(+)CD25(-) T cells. Phenotype analysis and FoxP3 expression were assessed by flow cytometry. Clinically-relevant CsA and RAPA concentrations significantly enhanced to a similar extent the suppressive activity of Tregs. Although this effect was associated with an increase in Treg number as well as in FoxP3 expression with both drugs, the driving mechanism seemed to be primarily quantitative (i.e. increase of the cell number) for RAPA, whereas mainly qualitative (i.e. increase in FoxP3 levels) for CsA, respectively. Conversely, MPA did not show any effect on Treg function and number. These findings suggest that both RAPA and CsA may be beneficial in promoting Treg-dependent allograft tolerance after organ transplantation.

P033 : IMPACT OF CYP3A5 POLYMORPHISMS ON THE METABOLISM OF TACROLIMUS IN RENAL TRANSPLANT RECIPIENTS DURING A 4-YEAR FOLLOW-UP

Aim To analyze the association between CYP3A5 single nucleotide polymorphisms (SNPs) and tacrolimus (Tac) or cyclosporine (CsA) level in renal transplant recipients during a 4-year follow-up. Methods 103 renal transplant patients were recruited and assigned into three groups according to their CYP3A5 allele ∗ 3/ ∗ 3, ∗ 1/ ∗ 3, or ∗ 1/ ∗ 1. The concentrations of Tac or CsA at time zero (C0) were measured before the drug administration. And the association between different alleles with Tac or CsA dose-adjusted C0 were further analyzed. Results During the first month after transplantation, recipients with CYP3A5 ∗ 3/ ∗ 3 allele exhibited significantly higher Tac C0 than the recipients with CYP3A5 ∗ 1/ ∗ 1 allele. The Tac dose/day used for recipients with CYP3A5 ∗ 3/ ∗ 3 allele was significantly lower than that for recipients with CYP3A5 ∗ 1/ ∗ 1 or CYP3A5 ∗ 1/ ∗ 3 allele. The Tac C0 of recipients with CYP3A5 ∗ 3/ ∗ 3 allele was significantly difference than that of the recipients with CYP3A5 ∗ 1/ ∗ 3 and CYP3A5 ∗ 1/ ∗ 1 allele at 3 months, 6 months, 12 months, 24 months and 48 months respectively during the 4-year follow-up after transplantation. The trough concentrations/doses of CsA were not associated with the CYP3A5 SNPs. Conclusion Patients with homozygous CYP3A5 ∗ 3/ ∗ 3 allele need less dosage of Tac to maintain a therapeutic concentration after renal transplantation.

Differential effects of cyclosporine A and TGFβ1 on IgE- versus IL-33-mediated mast cell activation (HYP3P.407)

Abstract Cyclosporine A (CsA), a potent calcineurin antagonist and immunosuppressant, is known to inhibit IgE-mediated mast cell activation. The present research investigates the role of this drug in suppressing IL-33-mediated mast cell activation. IL-33 is a novel cytokine of IL-1 family that elicits mast cells to produce inflammatory cytokines independently of IgE-FcεRI signals. We have found that low concentrations of CsA (10nM) are capable of suppressing IgE-mediated cytokine production by 50-80% in mouse bone marrow-derived mast cells. By comparison, IL-33-mediated secretion of TNF, IL-6, and MCP-1 was unaffected by CsA under these conditions. These results were consistent among mast cells derived from C57BL/6, 129Sv, C3H, and A/J mouse strains. We have previously reported that TGFβ1 inhibits IgE-mediated cytokine production. Our current experiments showed that TGFβ1 similarly antagonizes IL-33-induced cytokine secretion, and that CsA does not enhance this effect. These data demonstrate that mast cell activation by IL-33, thought to be a key regulator of innate immunity, is responsive to TGFβ1-mediated suppression, but relatively resistant to CsA effects. Understanding how mast cells are regulated by innate signals will shed light on many inflammatory diseases.

The influence of CYP3A, PPARA, and POR genetic variants on the pharmacokinetics of tacrolimus and cyclosporine in renal transplant recipients

PurposeTacrolimus (Tac) and cyclosporine (CsA) are mainly metabolized by CYP3A4 and CYP3A5. Several studies have demonstrated an association between the CYP3A5 genotype and Tac dose requirements. Recently, CYP3A4, PPARA, and POR gene variants have been shown to influence CYP3A metabolism. The present study investigated potential associations between CYP3A5*3, CYP3A4*22, PPARA c.209-1003G>A and c.208 + 3819A>G, and POR*28 alleles and dose-adjusted concentrations (C/D) of Tac and CsA in 177 renal transplant patients early post-transplant.MethodsAll patients (n = 177) were genotyped for CYP3A4*22, CYP3A5*3, POR*28, PPARA c.209-1003G>A, and PPARA c.208 + 3819A>G using real-time polymerase chain reaction (PCR) and melting curve analysis with allele-specific hybridization probes or PCR restriction fragment length polymorphisms (RFLP) methods. Drug concentrations and administered doses were retrospectively collected from patient charts at Oslo University Hospital, Rikshospitalet, Norway. One steady-state concentration was collected for each patient.ResultsWe confirmed a significant impact of the CYP3A5*3 allele on Tac exposure. Patients with POR*28 and PPARA variant alleles demonstrated 15 % lower (P = 0.04) and 19 % higher (P = 0.01) Tac C0/D respectively. CsA C2/D was 53 % higher among CYP3A4*22 carriers (P = 0.03).ConclusionThe results support the use of pre-transplant CYP3A5 genotyping to improve initial dosing of Tac, and suggest that Tac dosing may be further individualized by additional POR and PPARA genotyping. Furthermore, initial CsA dosing may be improved by pre-transplant CYP3A4*22 determination.Electronic supplementary materialThe online version of this article (doi:10.1007/s00228-014-1656-3) contains supplementary material, which is available to authorized users

Camphor sulfonic acid (CSA) doped polypyrrole (PPy) films: Measurement of microstructural and optoelectronic properties

In this paper, camphor sulfonic acid doped polypyrrole have been successfully prepared using different weight percentages of camphor sulfonic acid (10–50%) dispersed in polypyrrole by solid state synthesis method. Films of CSA doped PPy were prepared by spin coating technique on a glass substrate. The effect of varying concentrations of CSA on the structure, morphology, optical and electrical properties of polypyrrole was explored using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) atomic force microscopy (AFM), UV–visible spectroscopy and two probe technique respectively. The presence of CSA in PPy matrix and their interaction was confirmed by using XRD and FTIR techniques. The dramatic change in the surface morphology has been observed with increasing content of CSA in PPy matrix. The AFM study shows porous uniform globular morphology. The UV–vis spectra of CSA doped PPy film was found to shift to a lower wavelength side as compared to those of observed in PPy, indicating synergetic interaction between dopant CSA and PPy. CSA doped PPy not only can maintain a good solubility but also enhance the electrical conductivity. The results of dc electrical conductivity shows that, increase in electrical conductivity of PPy with increasing content of CSA (10–50%) in PPy matrix.

Effects of Cyclosporine A in Ex Vivo Reperfused Pig Lungs

Several works highlight the role of CsA in the prevention of IRI, but none focus on isolated lungs. Our objective was to evaluate the effects of CsA on IRI on ex vivo reperfused pig lungs. Thirty-two pairs of pig lungs were collected and stored for 30 minutes at 4 °C. The study was performed in four groups. First, a control group and then three groups receiving different concentrations of CsA (1, 10, and 30 μM) at two different times: once at the moment of lung procurement and another during the reperfusion procedure. The ex vivo lung preparation was set up using an extracorporeal perfusion circuit. Gas exchange parameters, pulmonary hemodynamics, and biological markers of lung injury were collected for the evaluation. CsA improved the PaO2 /FiO2 ratio, but it also increased PAP, Pcap, and pulmonary vascular resistances with dose-dependent effects. Lungs treated with high doses of CsA displayed higher capillary-alveolar permeability to proteins, lower AFC capacities, and elevated concentrations of pro-inflammatory cytokines. These data suggest a possible deleterious imbalance between the beneficial cell properties of CsA in IRI and its hemodynamic effects on microvascularization.

Long‐term outcomes after cyclosporine or mycophenolate withdrawal in kidney transplantation – results from an aborted trial

Long-term triple immunosuppressive therapy with cyclosporine (CsA), mycophenolate mofetil (MMF) and prednisolone may be excessively powerful for many transplant recipients. We compared withdrawal of either MMF or CsA in stable kidney transplants on triple immunosuppression. The study was a prospective, randomized, controlled 12-months trial in stable kidney transplants. The patients who withdrew CsA were given MMF 2 g/d, and CsA troughs were between 75 and 125 ng/mL in MMF withdrawal. Planned inclusion was 298 patients. The study was prematurely aborted after inclusion of 39 patients. Acute rejection rates were 6/20 (30%) in the MMF group compared with 0/19 (0%) in the CsA group (p = 0.02). Time to acute rejections was 4.0-28.7 months after withdrawal. Trough concentrations of mycophenolic acid (MPA) and CsA showed therapeutic levels. The subjects have been observed for eight yr, and of the 28 patients remaining on randomized therapy, the MMF patients preserved graft function better than CsA patients. Death-censored graft survival was 75% and 95% (p = 0.18) and patient survival was 70% and 68% (p = 0.99) in the MMF and CsA groups, respectively, at the end of long-term follow-up. CsA withdrawal was associated with a high rate of acute rejections. Initially, the treatment of acute rejections was successful. However, five of six lost their grafts in the long term.