CYP3A5 Polymorphisms Research Articles

The effect of caffeine dose on caffeine and paraxanthine changes in serum and saliva and CYP1A2 enzyme activity in athletes: a randomized placebo-controlled crossover trial

BackgroundAlthough caffeine (CAF) supplementation has been shown to improve exercise performance, its dose-dependent effect on CAF metabolism has not been sufficiently investigated. The aim of this study was to evaluate the effects of 3, 6 and 9 mg of CAF/kgBM on changes of CAF and paraxanthine (PRX) in the serum and saliva at four time-points.MethodsIn a randomized, double-blind, placebo-controlled crossover design, acute pre-exercise supplementation in 26 moderately-trained athletes, participating in high-intensity functional training (HIFT), was examined. The study protocol involved CAF/PRX biochemical analyses of serum and saliva with respect to CYP1A2 polymorphism and CYP1A2 enzyme activity.ResultsDespite significant differences between the serum and saliva levels of CAF and PRX, there was no difference in the PRX/CAF ratio. The interaction effect of dose and time-points for PRX concentration was revealed. The main effects of dose were observed for CAF and the PRX/CAF ratio. The main effect of time-points was registered only for serum CAF.ConclusionsDose- and time-dependent effect of CAF supplementation on CAF and PRX in the serum and saliva of athletes was confirmed, but there was no effect of the CAF dose on CYP1A2 enzyme activity, nor was there an interaction of CYP1A2 with enzyme inducibility. The CAF/PRX correlation indicated the possibility of interchangeable use of serum and/or saliva analyses in exercise studies.Clinical trial registrationThis trial was registered prospectively at ClinicalTrials.gov (NCT03822663, registration date: 30/01/2019).

CYP3A4*1B and CYP3A5*3 SNPs significantly impact the response of Egyptian candidates to high-intensity statin therapy to atorvastatin

BackgroundA single nucleotide polymorphism (SNP) is a variation in the DNA sequence that results from the alteration of a single nucleotide in the genome. Atorvastatin is used to treat hypercholesterolemia. It belongs to a class of drugs called statins, which lower elevated levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Research findings on the associations between the response to atorvastatin and genetic polymorphisms in CYP3A4 and CYP3A5 are inconclusive. The effects of CYP3A4*1B (rs2740574 C/T) and CYP3A5*3 (rs776746 T/C) on atorvastatin therapy have not been previously studied among Egyptians.ObjectiveThis research aimed to investigate the effects of the genetic polymorphisms CYP3A4*1B and CYP3A5*3 on atorvastatin treatment in Egyptians.MethodsIn this prospective cohort study, 100 subjects were genotyped for these SNPs. All participants were screened for serum lipid profiles, liver enzymes, total bilirubin (TB), and creatine kinase (CK) before and after 40 mg postatorvastatin therapy. Atorvastatin plasma levels were assessed posttreatment; atorvastatin pharmacokinetics were evaluated in five carriers of the CYP3A4*1B (T/T) and CYP3A5*3 (C/C) genotypes.ResultsThe allele frequencies of the CYP3A4*1B and CYP3A5*3 SNPs were 86% and 83%, respectively. The CYP3A4*1B (T/T) and CYP3A5*3 (C/C) genotypes significantly improved the serum triglyceride (TG) level (P < 0.05) and elevated the TB level (P < 0.001). Atorvastatin plasma levels were greater in CYP3A4*1B (T/T) (P < 0.05) and CYP3A5*3 (C/C) (P < 0.001) genotype carriers. Both SNPs significantly affected the pharmacokinetics of atorvastatin compared with those of Egyptian volunteers and various ethnic populations.ConclusionsThe CYP3A4*1B and CYP3A5*3 variants were prevalent in the study participants and could impact the effectiveness and safety of atorvastatin therapy. The mutant genotype of the CYP3A4*1B SNP and the CYP3A5*3 SNP led to high atorvastatin levels. Both variants had a notable effect on the pharmacokinetics of atorvastatin among Egyptians compared with healthy Egyptians and volunteers from other ethnic populations. Overall, clinicians can learn more about the impact of both variants in response to atorvastatin.Graphical

Dosing strategy of tacrolimus when co-administered with Wuzhi tablet in renal transplant recipients.

Tacrolimus (TAC) is a first-line immunosuppressant to prevent allograft rejection. Wuzhi tablet is widely used as a TAC-sparing agent in China that could significantly elevate TAC exposure. However, insufficient data support the dose recommendation of TAC when co-administered with Wuzhi. A total of 305 adult renal transplant patients with 2,541 TAC trough concentrations (C0) were enrolled for population pharmacokinetic (PPK) modeling. CYP3A5 polymorphism was genotyped, and corresponding clinical factors were recorded. Nonlinear mixed-effects modeling and Monte Carlo simulation were used for dose recommendation. PK parameters were calculated based on one-compartment model with first-order absorption and elimination. The estimated total clearance (CL/F) and volume of distribution (Vd/F) of TAC were 23.84 L/h and 1,075.96 L, respectively. Wuzhi, CYP3A5 genotype, hematocrit (HCT), and weight were found to have a significant influence on CL/F. CL/F was significantly lower in the individuals who were CYP3A5 non-expressers and received TAC together with Wuzhi. CYP3A5 genotype (expressers or non-expressers), body weight (40-80 kg), and hematocrit (20 - 40%) were selected as the specific clinical scenarios, and the starting dose of TAC ranged from 1.5 to 4.5 mg when co-administered with Wuzhi. We establish a TAC PPK model comprising Wuzhi as a covariate in renal transplant recipients and recommend an initial dose of TAC when co-administered with Wuzhi, which could provide reference for the individualized regimens of TAC.

Effects of CYP3A5 Genetic Polymorphisms on the Weight-adjusted through Concentration of Sirolimus in Renal Transplant Recipients: A Systematic Review and Meta-analysis.

Sirolimus, one of the immunosuppressive drugs administered to renal transplant recipients, is metabolized by cytochrome P450 (CYP) 3A5. Accordingly, CYP3A5 polymorphism is a genetic factor affecting sirolimus pharmacokinetics (PK). Therefore, we conducted a systematic review and meta-analysis on the association between sirolimus PK and CYP3A5*3 polymorphism. We searched for studies published up to 13 June 2024 from PubMed, Embase, Cochrane Library, and Web of Science. We reviewed studies on the relationship between CYP3A5*3 polymorphism and weightadjusted trough concentration/dose (C0 /D) ratio and dosage of sirolimus in renal transplant recipients, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We evaluated mean differences (MDs) and 95% confidence intervals (CIs). A total of seven studies were included. The weight-adjusted C0 /D ratio of sirolimus was significantly higher in patients with the CYP3A5*3/*3 rather than CYP3A5*1/*1 or CYP3A5*1/*3 genotype (MD 95.27 ng/mL per mg/kg; 95% CI: 58.06, 132.47; I2 = 74%; p < 0.00001). Also, the weight-adjusted dosage of sirolimus was significantly lower in patients with the CYP3A5*3/*3 rather than CYP3A5*1/*1 or CYP3A5*1/*3 genotype (MD -2.60 × 10-3 mg/kg; 95% CI: -4.52, -0.69; I2 = 44%; p = 0.008). Our meta-analysis showed a significant effect for the CYP3A5*3 genotype on weight-adjusted C0 /D ratio and dosage of sirolimus in adult renal transplant recipients.

CYP3A5 pharmacogenetic testing for tacrolimus in pediatric heart transplant patients: a budget impact analysis.

Pharmacogenomic testing can optimize drug efficacy and minimize adverse effects. CYP3A5 polymorphisms affect the metabolism of tacrolimus. We sought to estimate the budget impact of preemptive pharmacogenomic testing for CYP3A5 in pediatric heart transplantation patients from an institutional perspective. A decision tree was constructed to estimate the budget impact of pediatric heart transplant patients (age ≤18 years) initiated on tacrolimus with and without CYP3A5 pharmacogenomic testing. The budget impact of preemptive pharmacogenomic testing versus no pharmacogenomic testing was calculated. One-way sensitivity analysis and alternative analyses were conducted to assess the robustness of results to changes in model parameters. CYP3A5 genotype-guided dosing provided savings of up to $17 225 per patient compared to standard dosing. These savings decreased to $11 759 when using another institution's data for the standard-dosing group. The time to achieve therapeutic concentration in the poor metabolizer genotype-guided dosing group had the largest impact on cost savings while the cost of the pharmacogenetic test had the smallest impact on cost savings. Implementing CYP3A5 testing could save $17 225 per pediatric heart transplant patient receiving tacrolimus. As pharmacogenomic testing becomes more widespread, institutions should track resource requirements and outcomes to determine the best implementation policies going forward.

A 6-year retrospective study of olanzapine plasma concentration inpatients with schizophrenia CYP1A2 polymorphisms in real-life settings

Aimto investigate the potential influence of CYP1A2 polymorphisms on olanzapine plasma concentration of inpatients with schizophrenia in real-life settings. Methods409 inpatients who received OLA for at least 2 weeks, from June 2016 to March 2022 were included in the retrospective investigation. Moreover, 503 samples of above inpatients receiving OLA was built to investigate the influence of the relevant OLA plasma concentration, polymorphisms CYP1A2 -163C/A on the inpatients outcome. ResultsScale score reduction rate (SSRR) in 1 mutated CYP1A2 -163C/A alleles (CA) was significantly higher than other CYP1A2 alleles (CC + AA) (P = 0.002). Inverse S-curve correlations relationship was between SSRR and plasma concentrations of OLA (r = 0.130, P < 0.005). When remove ineffective subjects (ineffective group), the results of all CYP1A2 -163C/A genotype showed perfect correlations relationship tendencies with SSRR (r = 1.000). The best concentrations of OLA corrected for daily dose (C/D) range and the best concentration range of OLA of all CYP1A2 -163C/A genotype was 3.18–3.53 ng/mL/mg and 17.42–57.33 ng/mL. The C/D range and concentration range of OLA were 2.722–4.221 ng/mL/mg and 13.61–84.42 ng/mL, which belong CYP1A2 -163C/A CA genotype subjects, was largest. ConclusionsThe best effective C/D range and concentration range of OLA respective were 3.18–3.53 ng/mL/mg and 17.42–57.33 ng/mL, which range values of CYP1A2 -163C/A CA genotype of inpatients with schizophrenia was largest.

Influence of Genetic Polymorphisms on the Age at Cancer Diagnosis in a Homogenous Lynch Syndrome Cohort of Individuals Carrying the MLH1:c.1528C>T South African Founder Variant.

Background: High variability in the age at cancer diagnosis in Lynch syndrome (LS) patients is widely observed, even among relatives with the same germline pathogenic variant (PV) in the mismatch repair (MMR) genes. Genetic polymorphisms and lifestyle factors are thought to contribute to this variability. We investigated the influence of previously reported genetic polymorphisms on the age at cancer diagnosis in a homogenous LS cohort with a South African founder germline PV c.1528C>T in the MLH1 gene. Methods: A total of 359 LS variant heterozygotes (LSVH) from 60 different families were genotyped for specific genetic polymorphisms in GSTM1, GSTT1, CYP1A1, CYP17, PPP2R2B, KIF20A, TGFB1, XRCC5, TNF, BCL2, CHFR, CDC25C, ATM, TTC28, CDC25C, HFE, and hTERT genes using Multiplex Polymerase Chain Reaction and MassArray methods. Kaplan-Meier survival analysis, univariate and multivariate Cox proportional hazards gamma shared frailty models adjusted for sex were used to estimate the association between age at cancer diagnosis and polymorphism genotypes. A p-value < 0.05 after correcting for multiple testing using the Benjamini-Hochberg method was considered significant at a 95% confidence interval. Results: We identified three genotypes in the cell-cycle regulation, DNA repair, and xenobiotic-metabolism genes significantly associated with age at cancer diagnosis in this cohort. The CYP1A1 rs4646903 risk (GG) and CDC25C rs3734166 polymorphic (GA+AA) genotypes were significantly associated with an increased risk of a younger age at cancer diagnosis (Adj HR: 2.03 [1.01-4.08], p = 0.034 and Adj HR: 1.53 [1.09-2.14], p = 0.015, respectively). LSVH who were heterozygous for the XRCC5 rs1051685 SNP showed significant protection against younger age at cancer diagnosis (Adj HR: 0.69 [CI, 0.48-0.99], p = 0.043). The risk of a younger age at any cancer diagnosis was significantly high in LS carriers of one to two risk genotypes (Adj HR: 1.49 [CI: 1.06-2.09], corrected p = 0.030), while having one to two protective genotypes significantly reduced the risk of developing any cancer and CRC at a younger age (Adj HR: 0.52 [CI: 0.37-0.73], and Adj HR: 0.51 [CI: 0.36-0.74], both corrected p < 0.001). Conclusions: Polymorphism genotypes in the cell-cycle regulation, DNA repair, and xenobiotic metabolizing genes may influence the age at cancer diagnosis in a homogenous LS cohort with a South African founder germline PV c.1528C>T in the MLH1 gene.

The effect of gene polymorphism on ticagrelor metabolism: an in vitro study of 22 CYP3A4 variants in Chinese Han population.

Ticagrelor is a novel oral antiplatelet agent which can selectively inhibit P2Y12 receptor. Bleeding and dyspnea are common adverse reactions of ticagrelor in clinic. The side effects of ticagrelor are correlated with the plasma concentration of ticagrelor. This study aimed to evaluate the catalytic characteristics of 22 CYP3A4 alleles identified in the Chinese Han population on the metabolism of ticagrelor in vitro, focusing on the effect of CYP3A4 polymorphism on ticagrelor metabolism. In this study, insect cells were used to express 22 CYP3A4 variants, which were then incubated with 1-50 µM ticagrelor at 37 °C for 30 minutes to obtain the metabolite (AR-C124910XX). AR-C124910XX was detected by UHPLC-MS/MS to calculate the kinetic parameters, including Km, Vmax and CLint. Compared to the wild-type, most CYP3A4 alleles exhibited significant differences in intrinsic clearance. The intrinsic clearance of CYP3A4*11, *18 and *33 was much higher than that of wild-type; four variants exhibited similar intrinsic clearance values as the wild-type enzyme; The remaining 14 variants showed significantly reduced intrinsic clearance values, ranging from 1.48% to 75.11% of the wild-type; CYP3A4*30 displayed weak or no activity. This study conducted a comprehensive assessment of the effect of CYP3A4 variants on ticagrelor's metabolism. The results suggested that there is allele-specific activity towards ticagrelor in vitro. These findings can provide some insights and predictions for treatment strategies and risk assessments associated with ticagrelor in clinical practice.

Pharmacogenetic insights into ABCB1, ABCC2, CYP1A2, and CYP2B6 variants with epilepsy susceptibility among Egyptian Children: A retrospective case-control study

BackgroundPediatric epilepsy is a complicated neuropsychiatric disorder that is characterized by recurrent seizures and unusual synchronized electrical activities within brain tissues. It has a substantial effect on the quality of life of children, thus understanding of the hereditary considerations influencing epilepsy susceptibility and the response to antiepileptic medications is crucial. This study focuses on assessing the correlation of the ABCB1, ABCC2, CYP1A2, and CYP2B6 genetic polymorphisms with the susceptibility to epileptic seizures and their contributions to antiepileptic medication throughout the course of the disease. MethodsThis study included 134 Egyptian epileptic children, comprising 67 drug-responsive and 67 drug-resistant patients, along with 124 healthy controls matching for age, gender, and geographical district. Genotyping of the rs2032582, rs717620, rs2273697, rs762551, and rs3745274 variants was performed using the PCR technique. Statistical analyses, including haplotype, multivariate, logistic regression, and bioinformatics approaches, were conducted to evaluate the associations within the disease. ResultsThe ABCC2*rs717620 (T allele) revealed an increased risk of epilepsy compared to healthy controls (OR = 2.12, p-value < 0.001), with the rs717620 (C/T + T/T genotypes) showing significant differences between drug-responsive and drug-resistant patients (p-value < 0.05). Moreover, the ABCC2*rs2273697 (A allele) indicated a decreased risk of epileptic seizures compared to healthy controls (OR = 0.51, p-value = 0.033), with the rs2273697 (G/A + A/A genotypes) indicating a significant association with drug-resistant patients (OR = 0.21, p-value = 0.002). The rs717620*T/rs2273697*G haplotype was significantly correlated with an elevated risk of epileptic seizures within drug-responsive patients (OR = 2.26, p-value = 0.019). Additionally, the CYP1A2*rs762551 (A allele) represented a protective effect against epilepsy susceptibility (OR = 0.50, p-value < 0.001), with the rs762551 (G/A + A/A genotypes) disclosing a substantial association with a decreased risk of epileptic seizures among drug-resistant patients compared to drug-responsive patients (OR = 0.07, p-value < 0.001). Conversely, the ABCB1*rs2032582 (G allele) and the CYP2B6*rs3745274 (T allele) did not attain a significant difference with the epilepsy risk compared to healthy controls (p-value > 0.05). ConclusionsThe findings of our study emphasize the importance of pharmacogenetic screening in epilepsy research, particularly regarding to drug-resistant patients. The ABCC2*rs717620 variant conferred a significant correlation with elevated risk of epileptic seizures, while the ABCC2*rs2273697 and CYP1A2*rs762551 variants confirmed their contributions as protective markers against epilepsy development. Conversely, the ABCB1*rs2032582 and CYP2B6*rs3745274 alleles were not considered as independent risk factors with the course of epilepsy disease.

Role of CYP2D6 and CYP3A4 polymorphisms on aripiprazole and dehydroaripiprazole concentrations in patients undergoing long-acting treatment

Aripiprazole once-monthly (AOM) exhibits an important interindividual pharmacokinetic variability with significant implications for its clinical use. CYP2D6 and CYP3A4 highly contributes to this variability, as they metabolize aripiprazole (ARI) into its active metabolite, dehydroaripiprazole (DHA) and the latter into inactive metabolites.This study aims to evaluate the effect of CYP2D6 and CYP3A4 polymorphisms in combination and the presence of concomitant inducers and inhibitors of this cytochromes on ARI and DHA plasma concentrations in a real clinical setting.An observational study of a cohort of 74 Caucasian patients under AOM treatment was conducted. Regarding CYP2D6, higher concentrations were found for active moiety (ARI plus DHA) (AM) (67 %), ARI (67 %) and ARI/DHA ratio (77 %) for poor metabolizers (PMs) compared to normal metabolizers (NMs). No differences were found for DHA.PMs for both CYP2D6 and CYP3A4 showed a 58 % higher AM and 66 % higher plasma concentration for ARI compared with PMs for CYP2D6 and NMs for CYP3A4. In addition, PMs for both CYP2D6 and CYP3A4 have 45 % higher DHA concentrations than NMs for both cytochromes and 41 % more DHA than PMs for CYP2D6 and NMs for CYP3A4, suggesting a significant role of CYP3A4 in the elimination of DHA.Evaluating the effect of CYPD26 and CYP3A4 metabolizing state in combination on plasma concentrations of ARI, DHA and parent-to-metabolite ratio, considering concomitant treatments with inducers and inhibitor, could optimize therapy for patients under AOM treatment.

302.4: CYP3A5 polymorphism in kidney transplantation: individualizing tacrolimus dosing.

302.4: CYP3A5 polymorphism in kidney transplantation: individualizing tacrolimus dosing.

P.107: Pattern of CYP3A5 and MDR-1 single nucleotide polymorphism and its impact on tacrolimus levels and clinical outcomes in living renal allograft recipient.

P.107: Pattern of CYP3A5 and MDR-1 single nucleotide polymorphism and its impact on tacrolimus levels and clinical outcomes in living renal allograft recipient.

Distribution of CYP3A4 and CYP3A5 Polymorphisms and Genotype Combination Implicated in Tacrolimus Metabolism.

Human cytochrome P450 (CYP), particularly CYP3A4 and CYP3A5 is mainly responsible for the metabolism of several drugs including tacrolimus. Significant interracial/interethnic variation in the expression and function of CYP3A5 and CYP3A4 is caused by Single Nucleotide Polymorphisms (SNPs) of genes encoding these proteins. The present study investigated the genetic polymorphisms CYP3A4*1B, CYP3A4*22, and CYP3A5*3 in the Tunisian population. We included in this study, Tunisian healthy subjects and renal transplant recipients receiving tacrolimus. CYP3A4 and CYP3A5 genotyping were performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). According to the genotypic combination of the three CYP polymorphisms, we have identified for the first time four metabolizers statuses: slow metabolizers (SM), intermediate metabolizers (IM), high metabolizers (HM), and extensive metabolizers (EM). A total of 101 renal transplant patients and 102 healthy subjects were included. Our results showed that the predominant alleles in the Tunisian population are a wild type of CYP3A4*1B (0.87), likewise CYP3A4*22 (0.975) and CYP3A5*3 (0.82). The genotype frequencies of CYP3A4*1B, CYP3A4*22, and CYP3A5*3 were found to be 3.9%, 0.0%, and 69.5%, respectively. Also, we found a significant linkage disequilibrium between CYP3A4*1B and CYP3A5*3. We approved that the IM is the predominant phenotype in our population with 124 patients followed by and EM with 41 patients, HM in 29 patients and SM in 9 patients. These results showed that Tunisians are most similar to Caucasians. The genetic background of these enzymes CYP3A4*1B, CYP3A4*22, and CYP3A5*3 in this study are important in the prescription of personalized medicine.

Peripheral pathway gene variants in lifelong premature ejaculation: CYP19A1, CYP1A1, and CYP1A2 enzymes polymorphisms in Chinese Han men

Abstract Background Recent genetic association studies focusing on central pathways have been performed to investigate the correlation between susceptibility alleles and the risk of lifelong premature ejaculation (LPE). However, there remains a dearth of documented genes associated with peripheral pathways. Objective In this study we aimed to investigate the relationship between single nucleotide polymorphisms (SNPs) associated with the peripheral genes CYP19A1, CYP1A1, and CYP1A2 and the risk of LPE. Methods From August 2017 to August 2020, a total of 511 participants (139 LPE patients and 372 controls) were recruited. Trained medical professionals diagnosed LPE according to the standard definition set by the International Society for Sexual Medicine. Nine candidate SNPs were chosen and genotyped using the MassARRAY system. Allele and genotype frequencies of the SNPs among patients and controls were compared using the χ2 test. Logistic regression analysis, adjusted for age, was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) using PLINK version 1.9. Haploview software was employed to analyze linkage disequilibrium and haplotype distribution. The interaction among candidate SNPs concerning LPE risk was evaluated using multifactor dimensionality reduction. The relationship between selected polymorphisms and specific features was assessed using analysis of variance. Outcome Heterozygous SNPs located in the CYP19A1 (rs4646, rs17601876), CYP1A1 (rs1048943), and CYP1A2 (rs762551, rs2470890) genes showed significant correlations with the risk of LPE. Results The findings of this study confirmed that heterozygous SNPs in the CYP19A1 (rs4646 AC vs CC: OR, 1.84; CI, 1.10-3.09; rs17601876 AG vs GG: OR, 1.80; CI, 1.06-3.05) and CYP1A1 genes (rs1048943 CT vs TT: OR, 1.71; CI, 1.02-2.87), respectively, can significantly increase the LPE risk. Participant scores for the Premature Ejaculation Diagnostic Tool (P =.002) and International Index of Erectile Function-5 (P =.020) differed significantly by genotype for the different genotypes of CYP1A1-rs1048943. Haplotype analysis revealed strong linkage disequilibrium under CYP1A2_rs762551-rs2470890 (D' = 1.00). Clinical Implications The findings of this and other investigations of genetic determinants and potential pathogenic mechanisms of LPE may advance diagnostic and therapeutic opportunities in LPE patients. Strengths and Limitations In this study of LPE in men with CYP gene variants we addressed a current research gap. However, data on risk factors such as smoking and drinking were incomplete in both the case and control groups. In future studies we will expand the sample size and enhance data on risk factors for more precise assessments. Conclusion In summary, polymorphisms in the peripheral genes CYP19A1, CYP1A1, and CYP1A2 may play a role in LPE among Chinese men of the Han population.

Guidance on Selecting Optimal Steady-State Tacrolimus Concentrations for Continuous IV Perfusion: Insights from Physiologically Based Pharmacokinetic Modeling.

Introduction: The dose-response relationships of tacrolimus have been primarily assessed through trough concentrations during intermittent administrations. In scenarios where oral administration (PO) is unfeasible, continuous intravenous (IV) administration is advised. Under these circumstances, only steady-state (Css) plasma or blood concentrations are measured, with the absence of distinct trough levels (Cmin). Consequently, the measured concentrations are frequently misinterpreted as trough concentrations, potentially resulting in sub-therapeutic true tacrolimus blood levels. This study employs physiologically based pharmacokinetic modeling (PBPK) to establish the Css/Cmin ratio for tacrolimus across various clinical scenarios. Method: Using a validated PBPK model, the tacrolimus dose (both PO and IV) and the Css/Cmin ratios corresponding to matching area under the blood concentration-time curve during a dosage interval (AUCτ) values were estimated under different conditions, including healthy subjects and individuals exhibiting cytochrome P450 3A (CYP3A) interactions or CYP3A5 polymorphisms, along with a demonstration of a real-life clinical application. Result: In healthy volunteers, the oral/intravenous (PO/IV) dose ratio was found to be 4.25, and the Css/Cmin ratio was 1.40. A specific clinical case substantiated the practical applicability of the Css/Cmin ratio as simulated by PBPK, demonstrating no immediate clinical complications related to the transplant. When considering liver donors versus recipients expressing CYP3A5, the tacrolimus AUCτ was notably affected, yielding a PO/IV dose ratio of 4.00 and a Css/Cmin ratio of 1.75. Furthermore, the concomitant administration of the CYP3A inhibitor itraconazole given PO resulted in a PO/IV ratio of 1.75 with and a Css/Cmin ratio of 1.28. Notably, the inhibitory effect of itraconazole was diminished when administered IV. Conclusions: Through the application of PBPK methodologies, this study estimates the PO/IV dose ratios and Css/Cmin ratios that can enhance dose adjustment and therapeutic drug monitoring during the switch between IV and PO administration of tacrolimus in transplant patients, ultimately guiding clinicians in real-time decision-making. Further validation with in vivo data is recommended to support these findings.

Drug-induced enzyme activity inhibition and CYP3A4 genetic polymorphism significantly shape the metabolic characteristics of furmonertinib

This study aimed to elucidate the impact of variations in liver enzyme activity, particularly CYP3A4, on the metabolism of furmonertinib. An in vitro enzyme incubation system was established for furmonertinib using liver microsomes and recombinant CYP3A4 baculosomes, with analytes detected by LC-MS/MS. The pharmacokinetic characteristics of furmonertinib were studied in vivo using Sprague-Dawley rats. It was found that telmisartan significantly inhibited the metabolism of furmonertinib, as demonstrated by a significant increase in the AUC of furmonertinib when co-administered with telmisartan, compared to the furmonertinib-alone group. Mechanistically, it was noncompetitive in rat liver microsomes, while it was mixed competitive and noncompetitive in human liver microsomes and CYP3A4. Considering the genetic polymorphism of CYP3A4, the study further investigated its effect on the kinetics of furmonertinib. The results showed that compared to CYP3A4.1, CYP3A4.29 had significantly increased activity in catalyzing furmonertinib, whereas CYP3A4.7, 9, 10, 12, 13, 14, 18, 23, 33, and 34 showed markedly decreased activity. The inhibitory activity of telmisartan varied in CYP3A4.1 and CYP3A4.18, with IC50 values of 8.56 ± 0.90 μM and 27.48 ± 3.52 μM, respectively. The key loci affecting the inhibitory effect were identified as ARG105, ILE301, ALA370, and LEU373. Collectively, these data would provide a reference for the quantitative application of furmonertinib.

CYP19A1 polymorphisms and bladder cancer risk in the Chinese Han population

ABSTRACT Background The expression of CYP19A1 has implications for the prognosis of female bladder cancer. However, this study aimed to explore the association between single nucleotide polymorphisms (SNPs) in CYP19A1 and bladder cancer risk, as no prior research has addressed this association. Research design and methods We selected and genotyped five CYP19A1 SNPs (rs4646, rs6493487, rs1062033, rs17601876, and rs3751599) in 217 patients and 550 controls using the Agena MassARRAY system. Logistic regression analysis was employed to calculate the odds ratio (OR) and 95% confidence intervals (CIs). Bioinformatics predicted SNP functions and CYP19A1 involving pathways. Results Our study revealed a significant association between bladder cancer risk and four SNPs (rs4646 (AC vs. CC: OR = 1.71, FDR-p = 0.005), rs6493487 (G vs. A: OR = 0.68, FDR-p = 0.011), rs1062033 (G vs. C: OR = 0.36, FDR-p < 0.001), and rs17601876 (GA vs. GG: OR = 1.66, FDR-p = 0.008)) in CYP19A1. The three SNPs (rs4646, rs1062033, and rs17601876) were significantly correlated with CYP19A1 expression levels in normal whole blood (p < 0.05). Moreover, CYP19A1 was found to primarily participate in the steroid hormone biosynthesis and metabolic pathways. Conclusions Consequently, CYP19A1 gene polymorphisms may play a crucial role in the genetic susceptibility to bladder cancer.

Polycyclic aromatic hydrocarbon and its adducts in peripheral blood: Gene and environment interaction among Chinese population

BackgroundBenzo(a)pyrene (B[a]P) is the most widely concerned polycyclic aromatic hydrocarbons (PAHs), which metabolizes benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) in vivo to produce carcinogenic effect on the body. Currently, there is limited research on the role of the variation of metabolic enzymes in this process. MethodsWe carried out a study including 752 participants, measured the concentrations of 16 kinds PAHs in both particle and gaseous phases, urinary PAHs metabolites, leukocyte BPDE-DNA adduct and serum BPDE- Albumin (BPDE-Alb) adduct, and calculated daily intake dose (DID) to assess the cumulative exposure of PAHs. We conducted single nucleotide polymorphism sites (SNPs) of metabolic enzymes, explored the exposure–response relationship between the levels of exposure and BPDE adducts using multiple linear regression models. ResultOur results indicated that an interquartile range (IQR) increase in B[a]P, PAHs, BaPeq, 1-hydroxypyrene (1-OHP), 1-hydroxynaphthalene (1-OHNap) and 2-hydroxynaphthalene (2-OHNap) were associated with 26.53 %, 24.24 %, 28.15 %, 39.15 %, 12.85 % and 14.09 % increase in leukocyte BPDE-DNA adduct (all P < 0.05). However, there was no significant correlation between exposure with serum BPDE-Alb adduct (P > 0.05). Besides, we also found the polymorphism of CYP1A1(Gly45Asp), CYP2C9 (Ile359Leu), and UGT1A1(downstream) may affect BPDE adducts level. ConclusionOur results indicated that leukocyte BPDE-DNA adduct could better reflect the exposure to PAHs. Furthermore, the polymorphism of CYP1A1, CYP2C9 and UGT1A1affected the content of BPDE adducts.

A descriptive study of the single-nucleotide polymorphisms known to affect the Tacrolimus trough concentration per dose, among a population of kidney failure patients in a tertiary hospital in Ghana

BackgroundThe burden of chronic kidney disease (CKD) and kidney failure in Ghana is on the ascendency, with the prevalence of CKD estimated at 13.3%. Patients with CKD who progress to kidney failure require life sustaining kidney replacement therapy (KRT) which is almost exclusively available in Ghana as haemodialysis. Kidney transplantation is considered the best KRT option for patients with irreversible kidney failure due to its relative cost efficiency as well as its superiority in terms of survival and quality of life. However, because transplants may trigger an immune response with potential organ rejection, immunosuppressants such as tacrolimus dosing are required.ObjectiveThis study sought to determine single nucleotide polymorphisms in CYP3A5, CYP3A4 and MDR1 genes that affect the pharmacokinetics of Tacrolimus in a population of Ghanaian patients with kidney failure.MethodThis cross-sectional study comprised of 82 kidney failure patients undergoing maintenance haemodialysis at the Renal and Dialysis unit of Korle-Bu Teaching Hospital (KBTH). Clinical and demographic data were collected and genomic DNA isolated. Samples were genotyped for specific SNPs using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP).ResultsParticipants, 58/82 (70.73%) harbored the wildtype CYP3A5*1/*1 AA genotype, 20/82 (24.39%) carried the heterozygous CYP3A5*1/*3 AG genotype, and 4/82 (4.88%) had the homozygous mutant CYP3A5*3/*3 GG genotype. Also, 6/82 (7.32%) carried the wildtype AA genotype, 11/82 (13.41%) had the heterozygous AG genotype, and 65/82 (79.27%) harbored the homozygous mutant GG genotype of CYP3A4*1B (-290 A>G). For MDR1_Ex21 (2677 G>T), 81/82 (98.78%) carried the wildtype GG genotype, while 1/82 (1.22%) had the heterozygous GT genotype. For MDR1_Ex26 (3435 C>T), 63/82 (76.83%) had the wildtype CC genotype, while 18/82 (21.95%) carried the heterozygous CT genotype, and 1/82 (1.22%) harbored the mutant TT genotype.ConclusionSNPs in CYP3A4, CYP3A5, and MDR1 genes in a population of Ghanaian kidney failure patients were described. The varying SNPs of the featured genes suggest the need to consider the genetic status of Ghanaians kidney failure patients prior to transplantation and tacrolimus therapy.

DNA damage and its association with early-life exposome: Gene-environment analysis in Colombian children under five years old

Environmental exposures and gene-exposure interactions are the major causes of some diseases. Early-life exposome studies are needed to elucidate the role of environmental exposures and their complex interactions with biological mechanisms involved in childhood health. This study aimed to determine the contribution of early-life exposome to DNA damage and the modifying effect of genetic polymorphisms involved in air pollutants metabolism, antioxidant defense, and DNA repair. We conducted a cohort study in 416 Colombian children under five years. Blood samples at baseline were collected to measure DNA damage by the Comet assay and to determine GSTT1, GSTM1, CYP1A1, H2AX, OGG1, and SOD2 genetic polymorphisms. The exposome was estimated using geographic information systems, remote sensing, LUR models, and questionnaires. The association exposome-DNA damage was estimated using the Elastic Net linear regression with log link. Our results suggest that exposure to PM2.5 one year before the blood draw (BBD) (0.83, 95 %CI: 0.76; 0.91), soft drinks consumption (0.94, 0.89; 0.98), and GSTM1 null genotype (0.05, 0.01; 0.36) diminished the DNA damage, whereas exposure to PM2.5 one-week BBD (1.18, 1.06; 1.32), NO2 lag-5 days BBD (1.27, 1.18; 1.36), in-house cockroaches (1.10, 1.00; 1.21) at the recruitment, crowding at home (1.34, 1.08; 1.67) at the recruitment, cereal consumption (1.11, 1.04; 1.19) and H2AX (AG/GG vs. AA) (1.44, 1.11; 1.88) increased the DNA damage. The interactions between H2AX (AG/GG vs. AA) genotypes with crowding and PM2.5 one week BBD, GSTM1 (null vs. present) with humidity at the first year of life, and OGG1 (SC/CC vs. SS) with walkability at the first year of life were significant. The early-life exposome contributes to elucidating the effect of environmental exposures on DNA damage in Colombian children under five years old. The exposome-DNA damage effect appears to be modulated by genetic variants in DNA repair and antioxidant defense enzymes.