Ratio Of Tacrolimus Research Articles

Effect of CYP3A5 Gene Polymorphisms on Tacrolimus Blood Concentrations and Adverse Events in Allogeneic Hematopoietic Stem Cell Transplant Patients

BackgroundTacrolimus is the core basic immunosuppressant after transplantation. Cytochrome P450 3A5 (CYP3A5) is the main enzyme involved in tacrolimus metabolism, and rs776746A>G is the most frequently studied polymorphism in the CYP3A5 gene. The aim of this study was to investigate the effect of CYP3A5 gene polymorphisms on tacrolimus blood concentrations and acute graft versus host disease (GVHD) in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT). MethodsThis study included adult patients who received allo-HSCT at the First Affiliated Hospital of Wannan Medical College from January 2021 to June 2022, and received postoperative treatment with tacrolimus. Tacrolimus blood levels were obtained by fully automatic chemiluminescence immunoassay analyzer. Polymerase chain reaction/restriction fragment length polymorphism was used to genotype for CYP3A5*3 allelic variants. ResultsIn a total of 50 transplant patients, 30 patients were detected with CYP3A5*3/*3 genotype, 15 patients with CYP3A5*1/*3 genotype, and 5 patients with CYP3A5*1/*1 genotype. The initial tacrolimus blood concentrations in allo-HSCT patients with CYP3A5*1/*1, *1/*3, and *3/*3 genes were 7.75, 8.61, and 10.19 ng/mL, respectively; The initial blood concentration/dose (C/D) ratios were 4.08, 4.42 and 5.66 ng/(mL·mg), respectively. The C/D ratios of allo-HSCT patients carrying CYP3A5*1/*1, *1/*3, and *3/*3 genes were 4.35 and 4.71 and 5.58, 4.19, 4.56 and 5.71 ng/(mL·mg) in the second and 3rd weeks after operation. These results showed that the blood concentration and C/D ratio of tacrolimus in patients with CYP3A5*3/*3 genotype were significantly higher than those in patients with CYP3A5*1/*3 or CYP3A5*1/*1 genotype. Moreover, the incidence of acute GVHD after allo-HSCT in patients with CYP3A5*1/*1 genotype was significantly higher than that in patients with CYP3A5*1/*3 or CYP3A5*3/*3 genotype. ConclusionsMost patients carry the mutant allele CYP3A5*3. CYP3A5 gene polymorphisms affect tacrolimus blood concentrations and acute GVHD after allo-HSCT.

#1860 Oral semaglutide in diabetic kidney transplant recipients: Evaluating effectiveness and safety

Abstract Background and Aims Glucagon-like peptide 1 receptor agonists (GLP1-RA) have demonstrated cardiovascular and renal benefits in obese diabetic patients. However, the evidence for oral semaglutide in kidney transplant (KT) patients is very limited. Our study aims to analyze the effectiveness and safety of oral semaglutide in diabetic KT patients. Method Retrospective cohort study of KT with diabetes who started oral semaglutide in 3 Spanish hospitals (Puerta del Mar University Hospital, Jerez de la Frontera University Hospital and Puerto Real University Hospital) between December 2021 and December 2023. None of them had previously received subcutaneous GLP1-RA. Clinical and demographic variables were analyzed. Glomerular filtration rate (eGFR), proteinuria, and weight were collected at the start of the treatment and after 6 and 12 months. We analyze glycemic control, blood pressure, lipid profile and trough level, dose and C/D ratio of tacrolimus. Acute rejections (AR), de novo donor-specific antibodies (dnDSA) and adverse effects were documented. Parametric and non-parametric tests were performed according to the normality of the sample. Results In this period, 22 KT with DM started treatment with oral Semaglutide, of which 16 patients completed follow-up for 6 months and 11 patients for 1 year. Fourteen (63.6%) had developed post-transplant DM. The mean age was 61 years, and 77% were men. The mean baseline estimated glomerular filtration rate (eGFR) was 46.1 ml/min/1.73 m2, the baseline body mass index was 34.7 kg/m2 and the median KT vintage was 45 months. Three patients were on treatment with SGLT2i at the start of the drug. Variables compared during the follow-up are shown in Table 1. Four patients (18%) suffered gastrointestinal side effects. No dnDSA were documented during follow-up. One episode of AR was documented after drug initiation. Conclusions We show the longest series of oral semaglutide in KT patients. Our results support that it can be a good option for managing DM in KT, especially in obese patients.

Population pharmacokinetics of everolimus in adult liver transplant patients: Comparison to tacrolimus disposition and extrapolation to pediatrics.

Everolimus has recently been used to prevent graft rejection in liver transplantation and reduces the incidence of kidney dysfunction caused by calcineurin inhibitors. In this study, a population pharmacokinetic analysis was conducted to improve the individualization of everolimus therapy. Japanese post-liver transplant patients whose blood everolimus concentrations were measured between March 2018 and December 2020 were included in this study. A nonlinear mixed-effect modeling program was used to explore covariates that affect everolimus pharmacokinetics. Individual everolimus pharmacokinetic parameters estimated by the post-hoc Bayesian analysis using the final model were compared with the tacrolimus dose per trough concentration (D/C) ratio in each patient. The final model was extrapolated to pediatric liver transplant patients for external evaluation. A total of 937 concentrations from 87 adult patients were used in the model-building process. Everolimus clearance was significantly affected by the estimated glomerular filtration rate, concomitant use of fluconazole, sex, as well as total daily dose of everolimus (TDM effect). The estimated individual apparent clearance of everolimus by the post-hoc Bayesian analysis was moderately correlated with the D/C ratio of tacrolimus in each patient (R2 =0.330, p < 0.0001). The estimation accuracy in pediatric patients was considerably high, except for one infant out of 13 patients. In conclusion, population pharmacokinetic analysis clarified several significant covariates for everolimus pharmacokinetics in liver transplant patients. Everolimus pharmacokinetics moderately correlated with tacrolimus pharmacokinetics and could be extrapolated from adult to pediatric patients by body size correction, except for infants.

Effect of Itraconazole and Its Metabolite Hydroxyitraconazole on the Blood Concentrations of Cyclosporine and Tacrolimus in Lung Transplant Recipients.

Invasive Aspergillus infection is a major factor for poor prognosis in patients receiving lung transplantation (LT). An antifungal agent, itraconazole (ITCZ), that has antimicrobial activity against Aspergillus species, is used as a prophylactic agent against Aspergillus infection after LT. ITCZ and its metabolite, hydroxyitraconazole (OH-ITCZ), potently inhibit CYP3A and P-glycoprotein that metabolize or excrete calcineurin inhibitors (CNIs), which are the first-line immunosuppressants used after LT; thus, concomitant use of ITCZ and CNIs could induce an increase in the blood concentration of CNIs. However, no criteria for dose reduction of CNIs upon concomitant use with ITCZ in LT recipients have been defined. In this study, the effect of ITCZ and OH-ITCZ on the blood concentrations of two CNIs, tacrolimus and cyclosporine, after LT were retrospectively evaluated. A total of 39 patients who received LT were evaluated. Effects of ITCZ and OH-ITCZ on the concentration/dosage (C/D) ratio of tacrolimus and cyclosporine were analyzed using linear mixed-effects models. The plasma concentrations of OH-ITCZ were about 2.5-fold higher than those of ITCZ. Moreover, there was a significant correlation between the plasma concentrations of ITCZ and OH-ITCZ. Based on parameters obtained in the linear regression analysis, the C/D ratios of cyclosporine and tacrolimus increase by an average of 2.25- and 2.70-fold, respectively, when the total plasma concentration of ITCZ plus OH-ITCZ is 1000 ng/mL. In conclusion, the plasma levels of ITCZ and OH-ITCZ could be key factors in drawing up the criterion for dose reduction of CNIs.

Drug-Drug Interaction between Tacrolimus and Vonoprazan in Kidney Transplant Recipients.

Kidney transplant recipients with tacrolimus-based immunosuppressive therapy are often treated with proton-pump inhibitors (PPIs) to prevent gastric ulcer complications. Vonoprazan, a potassium-competitive acid blocker, is a novel PPI possessing different metabolic pathways from conventional PPIs (e.g., omeprazole, lansoprazole and rabeprazole). However, no data are available on the change in blood concentration of tacrolimus after switching rabeprazole, a conventional PPI, to vonoprazan coadministration in the initial period of post-transplantation. This is a retrospective study of 18 kidney transplant recipients. The blood concentration and the concentration to dose (C/D) ratio of tacrolimus were compared before and after switching from rabeprazole to vonoprazan. Impacts of CYP2C19 and CYP3A5 genetic polymorphisms on the drug–drug interaction were also examined. The median (range) trough concentration of tacrolimus was significantly increased from 5.2 (3.6–7.4) to 8.1 (6.1–11.7) ng/mL (p < 0.0005) after switching from rabeprazole to vonoprazan. The C/D ratio of tacrolimus was also significantly increased from 38.1 (16.5–138.1) to 48.9 (26.2–207.2) (p < 0.0005). The percent changes of tacrolimus concentrations and C/D were 65.8% and 41.8%, respectively. CYP2C19 and CYP3A5 genetic polymorphisms did not affect the change in concentration and C/D ratio of tacrolimus. The present study indicates that vonoprazan coadministration increases the tacrolimus concentration regardless of CYP2C19 or CYP3A5 genetic polymorphisms. Thus, frequent monitoring of blood tacrolimus concentration is required when vonoprazan is introduced as an intensive gastric acid blocker in the early phase of post-transplantation.

CYP3A5 and PPARA genetic variants are associated with low trough concentration to dose ratio of tacrolimus in kidney transplant recipients.

Genetic polymorphisms have been associated with variation in the metabolism of tacrolimus (TAC) in kidney transplant patients. This study is aimed at assessing the impact of allelic variants of CYP3A5 and PPARA genes on the pharmacokinetics (PK) of TAC in Brazilian kidney transplant recipients in the first-year post-transplant. A total of 127 patients were included for genetic evaluation. Genomic DNA was isolated from peripheral blood and real-time PCR was used to analyze the main polymorphisms described for the genes CYP3A5 (rs776746; C> G) and PPARA (rs4823613; A> G and rs4253728; G> A). CYP3A5 expressors showed a lower Co/dose ratio than non-expressors, with the median values of this parameter <1.01ng/mL/mg in the first group at all evaluated times. Additionally, PPARA variant homozygotes had a lower Co/D ratio than wild allele carriers in the 12-month post-transplant period, with a median value of 0.65ng/mL/mg. In the CYP3A5 expressers, the presence of the variant homozygous genotype PPARA was associated with a lower value of Co/D compared with the other genotypic groups at month 12. In the population under study, polymorphisms on CYP3A5 and PPARA were identified as determining and independent factors associated with the reduction of Co/D of TAC. Thus, the genotyping of these genetic variants may be a useful tool for the individualized prescription of TAC in kidney transplant patients.

Conversion ratio of tacrolimus switching from intravenous infusion to oral administration after lung transplantation.

BackgroundTo investigate the conversion ratio of tacrolimus switching from intravenous infusion to oral administration in patients after lung transplantation.MethodsWe retrospectively recruited patients received lung transplantation in the First Affiliated Hospital of Guangzhou Medical Hospital from January 2015 to June 2019. The blood concentration of tacrolimus administrated through intravenous infusion and oral administration were collected. The blood concentration, concentration/dose ratio (C/D), and (C/Dpo)/(C/Div) ratio were analyzed to explore the conversion ratio of tacrolimus switching from intravenous infusion to oral administration, as combined medication of tacrolimus and caspofungin were used.ResultsThe concentration of intravenously administered tacrolimus was significantly higher than that of oral administration; the C/D ratio of intravenously administrated tacrolimus (C/Div) was significantly higher than that of the oral administration (C/Dpo). There was a significant correlation between C/Dpo and C/Div (R2 =0.774, P<0.001). The conversion ratio of tacrolimus from intravenous administration to oral administration was 1:7.4, as combined medication of tacrolimus and caspofungin were used.ConclusionsThe conversion ratio of tacrolimus switching from intravenous to oral administration is 1:7.4 in the combination treatment of tacrolimus and caspofungin after lung transplantation.

The Clinical Impact of the C0/D Ratio and the CYP3A5 Genotype on Outcome in Tacrolimus Treated Kidney Transplant Recipients.

Tacrolimus is metabolized by CYP3A4 and CYP3A5 enzymes. Patients expressing CYP3A5 (in Caucasian patients about 15% of the population but more frequent in African Americans and Asians) have a dose requirement that is around 50% higher than non-expressers to reach the target concentration. CYP3A5 expressers can be considered fast metabolizers. The trough concentration/dose (C0/D) ratio of tacrolimus has recently been proposed as a prognostic marker for poor outcome after kidney transplantation. Patients with a low C0/D ratio (also referred to as fast metabolizers) seem to have more tacrolimus-related nephrotoxicity, more BK-viremia, and a lower graft survival. At first sight, the expression of CYP3A5 and a low C0/D ratio seem to be overlapping factors, both pointing towards patients in whom a higher tacrolimus dose is needed to reach the tacrolimus target concentration. However, there are important differences, and these differences may explain why the impact of the C0/D ratio on long term outcome is stronger than for CYP3A5 genotype status. Patients with a low C0/D ratio require a high tacrolimus dose and are exposed to high tacrolimus peak concentrations. The higher peak exposure to tacrolimus (and/or its metabolites) may explain the higher incidence of nephrotoxicity, BK-viremia and graft loss. A potential confounder is the concurrent maintenance treatment of corticosteroids, as steroids are sometimes continued in patients at high immunological risk. Steroids induce the metabolism of tacrolimus via pregnane X receptor mediated increased CYP3A4 expression, resulting in lower tacrolimus C0/D ratio in high risk patients. Also non-adherence may result in lower C0/D ratio which is also associated with poor outcome. The C0/D ratio of tacrolimus does seem to identify a group of patients with increased risk of poor outcome after kidney transplantation. Our recommendation is to monitor tacrolimus peak concentrations in these patients, and if these are high then target slightly lower pre-dose concentrations. Another possibility would be to switch to a prolonged release formulation or to dose the drug more frequently, in smaller doses, to avoid high peak concentrations.

Association of the IL-6 Rs1800796 SNP with Concentration/dose Ratios of Tacrolimus and Donor Liver Function after Transplantation

ABSTRACT Interleukin-6 (IL-6) is a proinflammatory cytokine that plays a range of important roles such as in inflammation, immune response, and cell growth regulation. Here, we aimed to assess the potential influence of the IL-6 single nucleotide polymorphism (SNP) rs1800796 on the concentration/dose (C/D) ratios of tacrolimus and donor liver function in Chinese liver transplant patients. A total of 331 liver transplant patients were included in this study. The C/D ratios and the ALT, AST, T-BIL, ALP, and GGT levels were analyzed at different time points in patients with and without the IL-6 rs1800796 SNP. The IL-6 rs1800796 polymorphism in recipients was found to be correlated with the C/D ratios of tacrolimus at months 2 to month 6 after transplantation. Also, the rs1800796 SNP in donors was found to influence liver function (shown in the data of ALT, AST, T-BIL, ALP and GGT) in recipients at the early post-transplant stage after transplantation. In conclusion, the IL-6 rs1800796 polymorphism was associated with the C/D ratios of tacrolimus and post-transplant donor liver function.

CYP3A5 Genotype as a Potential Pharmacodynamic Biomarker for Tacrolimus Therapy in Ulcerative Colitis in Japanese Patients.

Tacrolimus has been used to induce remission in patients with steroid-refractory ulcerative colitis. It poses a problem of large individual differences in dosage necessary to attain target blood concentration and, often, this leads to drug inefficacy. We examined the difference in mRNA expression levels of ATP binding cassette transporter B1 (ABCB1) between inflamed and non-inflamed tissues, and the influence of CYP3A5 genotype on tacrolimus therapy. The mRNA expression of CYP3A4 in colonic mucosa and that of cytochrome p450 3A5 (CYP3A5) and ABCB1 in inflamed and non-inflamed areas were examined in 14 subjects. The mRNA expression levels of CYP3A5 were higher than that of CYP3A4. The mRNA expression of ABCB1 was lower in the inflamed than in the non-inflamed mucosa, despite that of CYP3A5 mRNA level being not significantly changed. Hence, the deterioration of the disease is related to the reduction of the barrier in the inflamed mucosa. The relationship between CYP3A5 genotype and blood concentration, dose, and concentration/dose (C/D) ratio of tacrolimus in 15 subjects was studied. The tacrolimus dose to maintain equivalent blood concentrations was lower in CYP3A5*3/*3 than in CYP3A5*1 carriers, and the C/D ratio was significantly higher in the latter. Thus, CYP3A5 polymorphism information played a role in determining the initial dose of tacrolimus. Furthermore, since the effect of tacrolimus appears earlier in CYP3A5*3/*3 than in CYP3A5*1/*1 and *1/*3, it seems necessary to change the evaluation time of therapeutic effect by CYP3A5 genotype. Additionally, the relationship between CYP3A5 genotype and C/D ratio of tacrolimus in colonic mucosa was investigated in 10 subjects. Tacrolimus concentration in the mucosa was two-fold higher in CYP3A5*3/*3 than in CYP3A5*1 carriers, although no significant difference in tacrolimus-blood levels was observed. Therefore, the local concentration of tacrolimus affected by CYP3A5 polymorphism might be related to its therapeutic effect.

Effects of red blood cell concentrate transfusion on blood tacrolimus concentration.

Background Elevated blood concentration of tacrolimus is frequently observed following transfusion of red blood cell concentrate in patients after allogeneic hematopoietic stem cell transplantation. Objective The aim of this retrospective study was to clarify the effects of transfusion of red blood cell concentrate on the blood concentration of tacrolimus. Setting Chiba University Hospital in Japan. Method Fifty-two patients (aged 0-65years) receiving both tacrolimus and transfusion after allogeneic hematopoietic stem cell transplantation were enrolled. The ratio of measurement after transfusion to measurement before transfusion was calculated for hematocrit and blood concentration/dose ratio of tacrolimus (termed the hematocrit ratio and the tacrolimus ratio, respectively). Main outcome measure Change in blood concentration/dose ratio of tacrolimus and variable factors associated with variation in tacrolimus ratio. Results The blood concentration/dose ratio of tacrolimus was increased after transfusion compared with before transfusion (p < 0.001). A statistically significant correlation was seen between the hematocrit ratio and tacrolimus ratio (r = 0.32, p < 0.001). Hematocrit ratio, age or body surface area, and difference in aspartate aminotransferase level before and after transfusion were associated with the variation in tacrolimus ratio. There was no correlation between tacrolimus ratio and change in serum creatinine or potassium level in the short term. Conclusion Change in the blood concentration/dose ratio of tacrolimus was associated with change in the hematocrit ratio after transfusion, and more attention is required for children or patients with small body surface area. Dose adjustment of tacrolimus is required if the blood concentration of tacrolimus is much higher than the target concentration.

Relationship between the blood concentrations of tacrolimus and voriconazole in hematopoietic stem cell transplant recipients

We aimed to clarify the drug interaction between tacrolimus and voriconazole and investigate the relationship between blood concentrations of tacrolimus and voriconazole in hematopoietic stem cell transplantation (HSCT) patients. A retrospective study was conducted to investigate the relationship between blood concentration of tacrolimus and that of voriconazole at the Kindai University Nara Hospital. Patients who received HSCT and tacrolimus and were prescribed voriconazole for the prevention or treatment of aspergillosis from April 2010 to July 2018 were identified from the medical records. A total of 13 patients (administration route of tacrolimus: intravenously in 6 patients, orally in 7 patients) were enrolled in the present study. No significant correlation was observed between the blood concentration/dose (C/D) ratio of tacrolimus and the blood concentration of voriconazole (r = 0.38; p = 0.402; y = 102.8x + 928.1). However, a significant correlation was observed between the C/D ratio of tacrolimus and the blood concentration of voriconazole in the intravenous-administration group (r = 0.94; p = 0.0048; y = 421.9x + 810.5). Meanwhile, no significant correlation was observed in the oral-administration group (r = 0.43; p = 0.34; y = 7.9x + 719). The C/D ratio of tacrolimus was significantly correlated with the blood concentration of voriconazole when tacrolimus was intravenously administered. There was a difference in the mechanism of drug interaction between tacrolimus and voriconazole depending on the administration routes.

Estimation of Blood Sirolimus Concentration Based on Tacrolimus Concentration/Dose Normalized by Body Weight Ratio in Lung Transplant Patients.

Sirolimus and tacrolimus require accurate drug dosing based on their target blood levels to produce better clinical outcomes, specifically, the avoidance of drug-induced adverse effects and the maintenance of efficacy. However, because the ideal dose of sirolimus and the schedule for measuring its blood levels are unclear in lung transplant patients, an index is required for estimating sirolimus blood concentrations. The aim of this work is to study the correlation between the trough concentration/dose normalized by body weight (C0/D) ratios of sirolimus and tacrolimus in lung transplant patients. Thirteen lymphangiomyomatosis patients who underwent lung transplantation and were treated with sirolimus and tacrolimus from February 2015 to July 2018 were divided into 2 groups, one receiving twice-daily (TD, n = 6) and the other once-daily (OD, n = 7) tacrolimus formulations. The correlation between the C0/D ratio of sirolimus and patient background was evaluated using Spearman's rank correlation coefficient. Correlations between sirolimus and tacrolimus C0/D ratios or doses were analyzed by single regression analysis. Significant correlations were found between the C0/D ratios of sirolimus and tacrolimus. The regression equations from the initial data of TD and OD groups at steady state were y = 1.880x + 32.636 (adjusted R = 0.743, P = 0.017) and y = 1.684x + 38.816 (adjusted R = 0.919, P < 0.001), respectively. In addition, the regression equations from all data of TD and OD groups were y = 1.883x + 4.170 (adjusted R = 0.546, P < 0.001) and y = 1.950x + 43.188 (adjusted R = 0.898, P < 0.001), respectively. A significant correlation between the dosage of sirolimus and tacrolimus was observed only in the OD group, with relatively low accuracy. Blood sirolimus concentrations can be estimated using the C0/D ratio of tacrolimus, suggesting that the C0/D ratio of tacrolimus is an index of required sirolimus dosage and the frequency of blood sirolimus concentration measurements.

Effects of MDR1 1236C > T-2677G > T-3435C > T polymorphisms on the intracellular accumulation of tacrolimus, cyclosporine A, sirolimus and everolimus

1. Overexpression of P-glycoprotein (P-gp, encoded by MDR1) mediates resistance to multiple immunosuppressors. Several common MDR1 variants (1236C > T, 2677G > T, 3435C > T) impact the efflux activity of P-gp-mediated substrates. We assessed the effect of these polymorphisms on the sensitivity, intracellular accumulation, and efflux of tacrolimus, cyclosporine A, sirolimus and everolimus in transfected LLC-PK1 cells.2. LLC-PK1 cell lines were transfected with empty vector (pcDNA3.1) and recombinant MDR1T-T-T, MDR1C-T-T, MDR1C-G-T and MDR1C-G-C vectors, respectively and further screened in the presence of puromycin. The IC50 values, intracellular accumulation, and apparent permeability ratios of tacrolimus, cyclosporine A, sirolimus and everolimus were evaluated.3. MDR1 overexpression increased the resistance of LLC-PK1 cells to tacrolimus, cyclosporine A, sirolimus and everolimus. The resistance of cells expressing MDR1C-G-C wild-type haplotypes to tacrolimus were increased compared to MDR1T-T-T, MDR1C-T-T, MDR1C-G-T variant haplotypes. The efflux ability of P-gp-mediated tacrolimus in cells transfected with MDR1C-G-C was higher than cells overexpressing MDR1T-T-T, MDR1C-T-T, MDR1C-G-T variant haplotypes. In addition, the resistance of cells expressing MDR1C-G-C wild-type haplotypes to sirolimus were increased compared to MDR1C-T-T, MDR1C-G-T variant haplotypes. The efflux ability of P-gp-mediated sirolimus in cells overexpressing MDR1C-G-C was higher than cells transfected with MDR1C-T-T, MDR1C-G-T variant haplotypes.4. These findings indicate that wild-type MDR1 exports tacrolimus and sirolimus more efficiency than the MDR1T-T-T, MDR1C-T-T, MDR1C-G-T variant protein. This observation indicates that 1236C > T, 2677G > T, 3435C > T variant haplotypes drastically decrease the efflux ability of P-gp-mediated tacrolimus and sirolimus in a substrate-specific manner.

Impact of CYP3A5, POR, and CYP2C19 Polymorphisms on Trough Concentration to Dose Ratio of Tacrolimus in Allogeneic Hematopoietic Stem Cell Transplantation.

Single nucleotide polymorphisms in drug-metabolizing genes may affect tacrolimus pharmacokinetics. Here, we investigated the influence of genotypes of CYP3A5, CYP2C19, and POR on the concentration/dose (C/D) ratio of tacrolimus and episodes of acute graft-versus-host disease (GVHD) in Japanese recipients of allogeneic hematopoietic stem cell transplantation (HSCT). Thirty-six patients receiving the first HSCT using tacrolimus-based GVHD prophylaxis were enrolled with written informed consent. During continuous intravenous infusion, HSCT recipients carrying the CYP3A5*1 allele, particularly those with at least one POR*28 allele, had a significantly lower tacrolimus C/D ratio throughout all three post-HSCT weeks compared to that in recipients with POR*1/*1 (p < 0.05). The CYP3A5*3/*3 genotype and the concomitant use of voriconazole were independent predictors of an increased tacrolimus C/D ratio during the switch from continuous intravenous infusion to oral administration (p < 0.05). In recipients receiving concomitant administration of voriconazole, our results suggest an impact of not only CYP3A5 and CYP2C19 genotypes, but also plasma voriconazole concentration. Although switching from intravenous to oral administration at a ratio of 1:5 was seemingly appropriate in recipients with CYP3A5*1, a lower conversion ratio (1:2–3) was appropriate in recipients with CYP3A5*3/*3. Our results suggest that CYP3A5, POR, and CYP2C19 polymorphisms are useful biomarkers for individualized dosage adjustment of tacrolimus in HSCT recipients.

Recipient ABCB1, donor and recipient CYP3A5 genotypes influence tacrolimus pharmacokinetics in liver transplant cases.

Effective immunosuppression through optimization of trough levels tacrolimus reduces post-transplant mortality rate in liver transplant cases. Meta-analysis was carried out to evaluate how donor/recipient CYP3A5 (n = 678) and recipient ABCB1 (n = 318) genotypes influence tacrolimus pharmacokinetics till one-month of transplantation. The donor CYP3A5*3/*3 genotype exhibited higher concentration/dose (C/D) ratio of tacrolimus in week 1 (mean difference: 65.04, 95% CI: 15.30-114.79 ng/ml/mg/kg), week 2 (mean difference: 21.7, 95% CI: 12.6-30.9 ng/ml/mg/kg) and week 4 (mean difference: 43.28, 95% CI: 17.09 - 69.49 ng/ml/mg/kg) compared to *1/*1 and *1/*3 genotypes. The recipient CYP3A5 *3/*3 genotype did not showed significant difference in tacrolimus C/D ratio in week 1 compared to other two genotypes. However, week 2 (mean difference: 44.16, 95% CI: 3.68-84.65 ng/ml/mg/kg) and week 4 (mean difference: 43.74, 95% CI: 12.50-75.00 ng/ml/mg/kg) availability was higher in *3/*3 mutant recipients. However, the recipient ABCB1 3435 C > T polymorphism has no significant influence on tacrolimus pharmacokinetics till one month of transplant. The donor and recipient CYP3A5*3 polymorphism influences tacrolimus pharmacokinetics in the first month post-transplantation, whereas the association with recipient ABCB1 3435 C > T is inconclusive.

Serum Asunaprevir and Daclatasvir Concentrations and Outcomes in Patients with Recurrent Hepatitis C Who Have Undergone Living Donor Liver Transplantation.

This study's aim was to investigate the safety and effectiveness of asunaprevir and daclatasvir treatment for recurrent hepatitis C virus (HCV) infection in transplant recipients. The study cohort comprised 14 transplant recipients with recurrent hepatitis C who were receiving asunaprevir and daclatasvir. Serum concentrations of asunaprevir and daclatasvir, their therapeutic effects, trough concentrations/dose ratios of tacrolimus, and adverse effects were evaluated. Hepatitis C virus was still undetectable in 12 (85.7%) out of 14 patients 12 weeks after completing treatment. One week after starting treatment, asunaprevir concentrations were significantly higher in patients with baseline albumin concentrations ≤3.6 g/dl than in those with baseline albumin concentrations >3.6 g/dl. No marked fluctuations were identified in tacrolimus trough concentrations/dose ratios during the 24 weeks of therapy. Full doses of asunaprevir and daclatasvir-based treatment can be safely and effectively administered to liver transplant recipients for recurrent HCV genotype 1b after living donor liver transplantation (LDLT) with little effect on blood concentrations of tacrolimus.

Drug interactions and safety profiles with concomitant use of caspofungin and calcineurin inhibitors in allogeneic haematopoietic cell transplantation.

Small-scale clinical studies have reported on drug interactions between caspofungin (CPFG) and calcineurin inhibitors in healthy subjects; however, little is known about these interactions in allogeneic haematopoietic cell transplantation (allo-HCT) patients. We retrospectively assessed the drug interactions and safety profiles in allo-HCT recipients treated concomitantly with CPFG and calcineurin inhibitors. Ninety-one consecutive cases were evaluated. There were no statistically significant differences in the plasma concentration/dose (C/D) ratios of tacrolimus (TAC) in 34 patients before and after co-administration with CPFG (median: 575.6-672.4, P=0.200). In contrast, the median C/D ratio of cyclosporin A (CsA) in 16 patients was significantly elevated after co-administration with CPFG (median: 62.8-74.9, P=0.016). There were no serious adverse effects on liver or renal function associated with the therapy. Our data show that CPFG did not affect the pharmacokinetics of TAC and that it could mildly increase CsA blood concentrations in allo-HCT patients.

Failure of Calcineurin Inhibitor (Tacrolimus) Weaning Randomized Trial in Long-Term Stable Kidney Transplant Recipients.

Long-term renal transplant outcome is limited by side effects of immunosuppressive drugs, particularly calcineurin inhibitor (CNI). We assumed that some patients selected for a "low immunological risk of rejection" could be eligible and benefit from a CNI weaning strategy. We designed a prospective, randomized, multicenter, double-blind placebo-controlled clinical study (Eudract: 2010-019574-33) to analyze the benefit-risk ratio of tacrolimus weaning on highly selected patients (≥4 years of transplantation, normal histology, stable graft function, no anti-HLA immunization). The primary endpoint was improvement of renal function. Fifty-two patients were scheduled in each treatment arm, placebo compared to the CNI maintenance arm. Only 10 patients were eligible and randomized. Five patients were assigned to the placebo arm and five were assigned to the tacrolimus maintenance arm. In the tacrolimus maintenance arm, all patients maintained stable graft function and no immunological events occurred. Contrastingly, in the placebo arm, all five patients had to reintroduce a full dose of tacrolimus since three of them presented an acute rejection episode (one humoral, one mixed, and one borderline) and two displayed anti-HLA antibodies without histological lesion (one donor-specific antibodies [DSA] and one non-DSA). Clearly, tacrolimus withdrawal must be avoided even in long-term highly selective stable kidney recipients.

Long-Term Influence of CYP3A5 Gene Polymorphism on Pharmacokinetics of Tacrolimus and Patient Outcome After Living Donor Liver Transplantation

BackgroundWe investigated a long-term association between donor/recipient CYP3A5 polymorphisms, pharmacokinetics of tacrolimus, and recipient outcomes in settings of living donor liver transplantation (LDLT). MethodsFrom February 2002 to November 2009, 67 couples of donor/recipients with tacrolimus administration, who could be genotyped for CYP3A5*3 and *1, were eligible in this study. We compared the dose-adjusted trough levels (C/D ratio) and dose/weight ratio of tacrolimus at 1 to 36 months postoperatively and recipient prognosis according to donor/recipient CYP3A5 polymorphisms; *1*1 in 7, *1*3 in 15, and *3*3 in 45, based on recipient genotype, and *1*1 in 1, *1*3 in 28, and *3*3 in 38, based on donor genotype. ResultsOn the basis of the data from C/D ratio and dose/weight ratio of tacrolimus, the recipients who had *1 allele and/or whose donor had *1allele required significantly high doses of tacrolimus with, compared with those without, all through 3 years after transplantation. These data allowed us to show the importance of not only recipient CYP3A5 polymorphisms but also donor polymorphisms to obtain the target tacrolimus blood concentration. The overall survival rates of the recipients with *1*1 (5-year survival rate: 28.6%) were significantly unfavorable, which might have been caused by over-immunosuppression, compared with those with *1*3 (5-year survival rate: 78.8%) and *3*3 genotype (5-year survival rate: 84.3%). ConclusionsImmune suppressive therapy with the use of tacrolimus should be tailored on the basis of CYP3A5 genotype, which may reduce the adverse effects and improve graft outcome.