Bioengineered. 2021 Dec;12(1):5428-5439. doi: 10.1080/21655979.2021.1967029.

ABSTRACT

Duchenne muscular dystrophy (DMD) is an X-linked recessive disease caused by a mutant dystrophin protein. DMD patients undergo gradual progressive paralysis until death. Chronic glucocorticoid therapy remains one of the main treatments for DMD, despite the significant side effects. However, its mechanisms of action remain largely unknown. We used bioinformatics tools to identify pathogenic genes involved in DMD and glucocorticoid target genes. Two gene expression profiles containing data from DMD patients and healthy controls (GSE38417 and GSE109178) were downloaded for further analysis. Differentially expressed genes (DEGs) between DMD patients and controls were identified using GEO2R, and glucocorticoid target genes were predicted from the Pharmacogenetics and Pharmacogenomics Knowledge Base. Surprisingly, only one gene, CXCL12 (C-X-C motif chemokine ligand 12), was both a glucocorticoid target and a DEG. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, Gene Ontology term enrichment analysis, and gene set enrichment analysis were performed. A protein-protein interaction network was constructed and hub genes identified using the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape. Enriched pathways involving the DEGs, including CXCL12, were associated with the immune response and inflammation. Levels of CXCL12 and its receptor CXCR4 (C-X-C motif chemokine receptor 4) were increased in X-linked muscular dystrophy (mdx) mice (DMD models) but became significantly reduced after prednisone treatment. Metformin also reduced the expression of CXCL12 and CXCR4 in mdx mice. In conclusion, the CXCL12-CXCR4 pathway may be a potential target for DMD therapy.

PMID:34424816 | DOI:10.1080/21655979.2021.1967029

JAMA Neurol. 2021 Aug 23. doi: 10.1001/jamaneurol.2021.2806. Online ahead of print.

ABSTRACT

IMPORTANCE: The X chromosome represents 5% of the human genome in women and men, and its influence on cognitive aging and Alzheimer disease (AD) is largely unknown.

OBJECTIVE: To determine whether the X chromosome is associated with sex-specific cognitive change and tau pathology in aging and AD.

DESIGN, SETTING, PARTICIPANTS: This study examined differential gene expression profiling of the X chromosome from an RNA sequencing data set of the dorsolateral prefrontal cortex obtained from autopsied, elderly individuals enrolled in the Religious Orders Study and Rush Memory and Aging Project joint cohorts. Samples were collected from the cohort study with enrollment from 1994 to 2017. Data were last analyzed in May 2021.

MAIN OUTCOMES AND MEASURES: The main analysis examined whether X chromosome gene expression measured by RNA sequencing of the dorsolateral prefrontal cortex was associated with cognitive change during aging and AD, independent of AD pathology and at the transcriptome-wide level in women and men. Whether X chromosome gene expression was associated with neurofibrillary tangle burden, a measure of tau pathology that influences cognition, in women and men was also explored.

RESULTS: Samples for RNA sequencing of the dorsolateral prefrontal cortex were obtained from 508 individuals (mean [SD] age at death, 88.4 [6.6] years; 315 [62.0%] were female; 197 [38.8%] had clinical diagnosis of AD at death; 293 [58.2%] had pathological diagnosis of AD at death) enrolled in the Religious Orders Study and Rush Memory and Aging Project joint cohorts and were followed up annually for a mean (SD) of 6.3 (3.9) years. X chromosome gene expression (29 genes), adjusted for age at death, education, and AD pathology, was significantly associated with cognitive change at the genome-wide level in women but not men. In the majority of identified X genes (19 genes), increased expression was associated with slower cognitive decline in women. In contrast with cognition, X chromosome gene expression (3 genes), adjusted for age at death and education, was associated with neuropathological tau burden at the genome-wide level in men but not women.

CONCLUSIONS AND RELEVANCE: In this study, the X chromosome was associated with cognitive trajectories and neuropathological tau burden in aging and AD in a sex-specific manner. This is important because specific X chromosome factors could contribute risk or resilience to biological pathways of aging and AD in women, men, or both.

PMID:34424272 | DOI:10.1001/jamaneurol.2021.2806

Pharmacogenomics. 2021 Aug 23. doi: 10.2217/pgs-2021-0023. Online ahead of print.

ABSTRACT

Genetics play an important role in opioid use disorder (OUD); however, few specific gene variants have been identified. Therefore, there is a need to further understand the pharmacogenomics influences on the pharmacodynamics of opioids. The Pharmacogenomics Knowledgebase (PharmGKB), a database that links genetic variation and drug interaction in the body, was queried to identify polymorphisms associated with heroin dependence in the context of opioid related disorders/OUD. Eight genes with 22 variants were identified as linked to increased risk of heroin dependence, with three genes and variants linked to decreased risk, although the level of evidence was moderate to low. Therefore, continued exploration of biomarker influences on OUD, reward pathways and other contributing circuitries is necessary to understand the true impact of genetics on OUD before integration into clinical guidelines.

PMID:34424051 | DOI:10.2217/pgs-2021-0023

Oncologist. 2021 Aug 23. doi: 10.1002/onco.13953. Online ahead of print.

ABSTRACT

BACKGROUND: Several opioids have pharmacogenomic associations impacting analgesic efficacy. However, germline pharmacogenomic testing is not routinely incorporated into supportive oncology. We hypothesized that CYP2D6 profiling would correlate with opioid prescribing and hospitalizations.

PATIENTS AND METHODS: We analyzed 61,572 adult oncology patients from 2012-2018 for opioid exposures. CYP2D6 metabolizer phenotype (ultra-rapid [UM], normal metabolizer [NM], intermediate [IM], or poor [PM]), the latter two of which may cause inefficacy of codeine, tramadol, and standard-dose hydrocodone, was determined for patients genotyped for reasons unrelated to pain. The primary endpoint was number of opioid medications received during longitudinal care (IM/PMs vs NMs). Secondary endpoint was likelihood of pain-related hospital encounters.

RESULTS: Most cancer patients (n=34,675, 56%) received multiple opioids (average 2.8±1.6/patient). Hydrocodone was most commonly prescribed (62%), followed by tramadol, oxycodone, and codeine. In the CYP2D6 genotyped cohort (n=105), IM/PMs received a similar number of opioids (3.4±1.4) as NMs (3.3±1.9). However, IM/PMs were significantly more likely to experience pain-related hospital encounters compared to NMs, independent of other variables (odds ratio [OR]=5.4 [CI 1.2-23.6]; p=0.03). IM/PMs were also more likely to be treated with later-line opioids that do not require CYP2D6 metabolism, such as morphine and hydromorphone (OR=3.3, [CI 95% CI 1.1-9.8]; p=0.03).

CONCLUSION: CYP2D6 genotype may identify cancer patients at increased risk for inadequate analgesia when treated with typical first-line opioids like codeine, tramadol, or standard-dose hydrocodone. Palliative care considerations are an integral part of optimal oncology care, and these findings justify prospective evaluation of preemptive genotyping as a strategy to improve oncology pain management.

IMPLICATIONS FOR PRACTICE: Genomic variation in metabolic enzymes can predispose individuals to inefficacy when receiving opioid pain medications. Patients with intermediate and/or poor CYP2D6 metabolizer status do not adequately convert codeine, tramadol, and hydrocodone into active compounds, with resulting increased risk of inadequate analgesia. Our study showed that cancer patients frequently receive CYP2D6-dependent opioids. However, patients with CYP2D6 intermediate and poor metabolizer status had increased numbers of pain-related hospitalizations and more frequently required the potent non-CYP2D6 opioids morphine and hydromorphone. This may reflect inadequate initial analgesia with the common "first-line" CYP2D6-metabolized opioids. Preemptive genotyping to guide opioid prescribing during cancer care may improve pain-related patient outcomes.

PMID:34423496 | DOI:10.1002/onco.13953

Ann Transl Med. 2021 Jul;9(13):1066. doi: 10.21037/atm-20-7724.

ABSTRACT

BACKGROUND: The prognostic value of the CYP2C19 genotype in post-percutaneous coronary intervention (PCI) patients remains controversial. The recently-published, limited-sample PHARMCLO trial indicates a personalized pharmacogenomic approach may reduce adverse events. This study aimed to determine the prognostic value of CYP2C19 genotypes.

METHODS: The original cohort consisted of 10,724 PCI patients in 2013. 756 patients with genotyped CYP2C19 were included in our analysis. The CYP2C19 genotype prognostic value was tested based on different clinical factors. The primary endpoint was major adverse cardio- and cerebro-vascular event (MACCE).

RESULTS: MACCE 2-years post-PCI occurred in 19 patients (17.4%) in poor metabolizers (PM, CYP2C19 *2/*2, *2/*3, *3/*3), 43 patients (12.2%) in intermediate metabolizers (IM, CYP2C19 *1/*2 or *1/*3) and 27 patients (9.2%) in extensive metabolizers (EM, CYP2C19 *1/*1). PM was an independent MACCE predictor compared with EM (HR: 1.960, 95% CI: 1.139-3.372), but the difference between IM and PM was not significant (HR: 1.314, 95% CI: 0.843-2.048). Major bleeding (BARC grade ≥3) was not significantly different between the three groups (2.5% vs. 2.1% vs. 0.8%, P=0.133). Subgroup analysis showed that the CYP2C19 genotype prognostic value was present in the following subgroups: male, age >60 years, body mass index (BMI) >24 kg/m2, SYNTAX score >15, current smokers, and patients without chronic kidney disease.

CONCLUSIONS: Utilizing CYP2C19 genotype to guide post-PCI antiplatelet therapy might be appropriate in patients with the following characteristics: male, age >60 years, BMI >24 kg/m2, SYNTAX score >15, current smokers, and non-chronic kidney disease (CKD) patients.

PMID:34422978 | PMC:PMC8339845 | DOI:10.21037/atm-20-7724

Front Genet. 2021 Aug 5;12:736626. doi: 10.3389/fgene.2021.736626. eCollection 2021.

NO ABSTRACT

PMID:34422026 | PMC:PMC8375317 | DOI:10.3389/fgene.2021.736626

Int J Infect Dis. 2021 Aug 19:S1201-9712(21)00664-0. doi: 10.1016/j.ijid.2021.08.031. Online ahead of print.

ABSTRACT

BACKGROUND: Population pharmacokinetic analysis in critically ill infants remains a challenge and lacks information.

OBJECTIVES: To determine the population pharmacokinetic parameters of meropenem and evaluate the covariates affecting population pharmacokinetic parameters.

METHODS: A prospective study was conducted in 35 patients. A total of 160 blood samples were collected and determined free drug concentrations of meropenem. Population pharmacokinetic data were analyzed using NONMEM software. Internal validation methods, including bootstrapping and prediction-corrected visual predictive checks, were applied to evaluate the robustness and predictive power of the final model.

RESULTS: A one-compartment model with first-order elimination showed the best fit to the data. The typical values of clearance (CL) and volume of distribution (Vd) were 1.33 L/h and 2.27 L, respectively. Weight and creatinine clearance were influential covariates for CL, while weight was a significant covariate for Vd of meropenem. The model evaluation results suggested robustness and good predictability of the final model. The standard dosage regimens of meropenem achieved 40% f T>MIC but not enough if a more aggressive target of 80% f T>MIC at MIC value of ≥ 16 µg/mL.

CONCLUSIONS: This population pharmacokinetic model could be used for suggesting the individualized meropenem dosage regimens in critically ill infants.

PMID:34419581 | DOI:10.1016/j.ijid.2021.08.031

Environ Res. 2021 Aug 19:111901. doi: 10.1016/j.envres.2021.111901. Online ahead of print.

ABSTRACT

The experience gained over the last hundred years clearly indicates that two groups of viruses represent the main risk for the development of highly transmissible epidemics and pandemics in the human species: influenza viruses and coronaviruses (CoV). Although the search for viruses with pandemic potential in the environment may have an important predictive and monitoring role, it is still based on empirical methodologies, mostly resulting from the clinic and not fully validated for environmental matrices. As far as the SARS-CoV-2 pandemic, currently underway, is concerned, environmental monitoring activities aiming at checking the presence of SARS-CoV-2 in wastewater can be extremely useful to predict and check the diffusion of the disease. For this reason, the present study aims at evaluating the SARS-CoV-2 diffusion by means of a wastewater-based environmental monitoring developed in Piedmont, N-W Italy, during the second and third pandemic waves. Wastewater sampling strategies, sampling points sample pre-treatments and analytical methods, data processing and standardization, have been developed and discussed to give representative and reliable results. The following outcomes has been highlighted by the present study: i) a strong correlation between SARS-CoV-2 concentration in untreated wastewater and epidemic evolution in the considered areas can be observed as well as a predictive potential that could provide decision-makers with indications to implement effective policies, to mitigate the effects of the ongoing pandemic and to prepare response plans for future pandemics that could certainly arise in the decades to come; ii) moreover, the data at disposal from our monitoring campaign (almost 500 samples analysed in 11 months) confirm that SARS-CoV-2 concentrations in wastewater are strongly variable and site-specific across the region: the highest SARS-CoV-2 concentration values have been found in sewer networks serving the most populated areas of the region; iii) normalization of viral concentrations in wastewater through Pepper Mild Mottle Virus (a specific faecal marker) has been carried out and commented; iv) the study highlights the potential of wastewater treatment plants to degrade the genetic material referable to SARS-CoV-2 as well. In conclusion, the preliminary data reported in the present paper, although they need to be complemented by further studies considering also other geographical regions, are very promising.

PMID:34419466 | DOI:10.1016/j.envres.2021.111901

Nat Commun. 2021 Aug 20;12(1):5068. doi: 10.1038/s41467-021-25390-0.

ABSTRACT

p53 regulates several signaling pathways to maintain the metabolic homeostasis of cells and modulates the cellular response to stress. Deficiency or excess of nutrients causes cellular metabolic stress, and we hypothesized that p53 could be linked to glucose maintenance. We show here that upon starvation hepatic p53 is stabilized by O-GlcNAcylation and plays an essential role in the physiological regulation of glucose homeostasis. More specifically, p53 binds to PCK1 promoter and regulates its transcriptional activation, thereby controlling hepatic glucose production. Mice lacking p53 in the liver show a reduced gluconeogenic response during calorie restriction. Glucagon, adrenaline and glucocorticoids augment protein levels of p53, and administration of these hormones to p53 deficient human hepatocytes and to liver-specific p53 deficient mice fails to increase glucose levels. Moreover, insulin decreases p53 levels, and over-expression of p53 impairs insulin sensitivity. Finally, protein levels of p53, as well as genes responsible of O-GlcNAcylation are elevated in the liver of type 2 diabetic patients and positively correlate with glucose and HOMA-IR. Overall these results indicate that the O-GlcNAcylation of p53 plays an unsuspected key role regulating in vivo glucose homeostasis.

PMID:34417460 | DOI:10.1038/s41467-021-25390-0

J Control Release. 2021 Aug 17:S0168-3659(21)00429-6. doi: 10.1016/j.jconrel.2021.08.023. Online ahead of print.

ABSTRACT

CPX-351 is a liposome encapsulating cytarabine and daunorubicin for treating Acute Myeloid Leukemia (AML) patients. To what extent differences in cytidine deaminase (CDA) activity, the enzyme that catabolizes free cytarabine in the liver, can affect the pharmacokinetics of liposomal cytarabine as well, is unknown. We have studied the pharmacokinetics (PK) of released, liposomal and total cytarabine using a population-modeling approach in 9 adult AML patients treated with liposomal CPX-351. Exposure levels and PK parameters were compared with respect to the patient's CDA status (i.e., Poor Metabolizer (PM) vs. Extensive Metabolizer (EM)). Overall response rate was 75%, and 56% of patients had non-hematological severe toxicities, including one lethal toxicity. All patients had febrile neutropenia. A large (>60%) inter-individual variability was observed on pharmacokinetics parameters and subsequent drug levels. A trend towards severe toxicities was observed in patients with higher exposure of cytarabine. Results showed that liposomal CPX-351 led to sustained exposure with reduced clearance (Cl = 0.16 L/h) and prolonged half-life (T1/2 = 28 h). Liposomal nanoparticles were observed transiently in bone marrow with cytarabine levels 2.3-time higher than in plasma. Seven out of 9 patients were PM with a strong impact on the PK parameters, i.e., PM patients showing higher cytarabine levels as compared with EM patients (AUC: 5536 vs. 1784 ng/ml.h), sustained plasma exposure (T1/2: 33.9 vs. 13.7 h), and reduced clearance (Cl: 0.12 vs. 0.29 L/h). This proof-of-concept study suggests that CDA status has a major impact on cytarabine PK and possibly safety in AML patients even when administered as a liposome.

PMID:34416320 | DOI:10.1016/j.jconrel.2021.08.023

Clin Transl Sci. 2021 Aug 20. doi: 10.1111/cts.13124. Online ahead of print.

ABSTRACT

This multicenter clinical study was aimed at conducting a targeted pharmacogenomic association analysis of residual on-clopidogrel platelet reactivity in 474 Caribbean Hispanic patients. Platelet reactivity was measured using the VerifyNow P2Y12 assay and clopidogrel resistance was defined as P2Y12 reaction units (PRUs) greater than or equal to 208. Genotyping was performed using the whole-genome Infinium MEGA BeadChip array. An ancestry-adjusted, weighted polygenic risk score (wPGxRS) was developed to account for the effect of multiple variants on PRU and compared between clopidogrel responders and nonresponders. The mean PRU across the study cohort was 173.8 ± 68.5 and 33.5% of patients were defined as clopidogrel resistant. Multivariate linear regression showed that 19% of PRU variability was attributed to nine independent predictors, with CYP2C19*2 (rs4244285) accounting for ~ 7% of observed PRU variation (p < 0.001). PON1 rs662, ABCB1/MDR1 rs2032582, PEAR1 rs12041331 carrier status, and the interaction between African ancestry and rs12041331 carriers also predicted PRU among the participants (p ≤ 0.05). A clear gene-dose effect was detected between PRU and CYP2C19*2 genotype, consistent with previous studies in European patient populations, as well as rs12777823. Importantly, a significant positive correlation was detected between our novel wPGxRS (4 variants) and PRU among the Hispanic patient population (rp = 0.35, p < 0.001). Moreover, the wPGxRS discriminated between nonresponders and responders (p = 0.003), indicating that this multigene-based score is a useful predictor of clopidogrel resistance among Caribbean Hispanics. Taken together, these results help close the gap of knowledge on clopidogrel pharmacogenomics and its potential clinical implementation in this under-represented population.

PMID:34415683 | DOI:10.1111/cts.13124

Indian J Pharmacol. 2021 Jul-Aug;53(4):301-309. doi: 10.4103/ijp.IJP_593_19.

ABSTRACT

Hypertension is a leading age-related disease in our society and if left untreated, leads to fatal cardiovascular complications. The prevalence of hypertension has increased and becomes a significant global health economic burden, particularly in lower-income societies. Many loci associated with blood pressure and hypertension have been reported by genome-wide association studies that provided potential targets for pharmacotherapy. Pharmacogenetic research had shown interindividual variations in drug efficacy, safety, and tolerability. This could be due to genetic polymorphisms in the pharmacokinetics (genes involved in a transporter, plasma protein binding, and metabolism) or pharmacodynamic pathway (receptors, ion channels, enzymes). Pharmacogenetics promises great hope toward targeted therapy, but challenges remain in implementing pharmacogenetic aided antihypertensive therapy in clinical practice. Using various databases, we analyzed the underlying mechanisms between the candidate gene polymorphisms and antihypertensive drug interactions and the challenges of implementing precision medicine. We review the emergence of pharmacogenetics and its relevance to clinical pharmacological practice.

PMID:34414909 | DOI:10.4103/ijp.IJP_593_19

Pharmacogenomics. 2021 Aug 20. doi: 10.2217/pgs-2021-0037. Online ahead of print.

ABSTRACT

Aim: We evaluated the application and clinical impact of multi-gene pharmacogenetic testing in oncology palliative medicine. Patients & Methods: In a single-arm pilot trial, cancer patients with uncontrolled pain were assessed in a palliative medicine clinic at baseline and received pharmacogenetic testing. Results were used as applicable up to the final visit (day 30). Pain scores, opioid prescribing, and use of pharmacogenetic test results were collected. Results: In 75 patients, the median baseline pain score was 7/10. Of 54 evaluable at the final visit, 28 required opioid modifications and 19 had actionable genotypes, mostly CYP2D6. Pain improvement (≥2-point reduction) was higher than historical data (56 vs 30%; p < 0.001). There were no differences in pain improvement between those with and without actionable genotypes (61 vs 53%). Conclusion: Multi-gene testing identified actionable genotypes and may improve cancer pain.

PMID:34414777 | DOI:10.2217/pgs-2021-0037

Pharmacogenomics. 2021 Aug 20. doi: 10.2217/pgs-2020-0127. Online ahead of print.

ABSTRACT

Premise: The effects of proton pump inhibitors (PPI) depend on metabolic enzyme CYP2C19 that has different activity due to gene polymorphism. The purpose of this meta-analysis is to determine the potential effects of CYP2C19 polymorphism on the efficiency of PPI-based treatment. Materials & methods: The PubMed, EMBASE, Cochrane Library, etc. were searched for relevant articles published in English or Chinese from inception to 31 May 2020. Finally, 26 randomized controlled trials and 15 cohort studies met the inclusion criteria and used for the meta-analysis via STATA version 15. Results: Poor metabolizer (PM) genotype Helicobacter pylori eradication rates were highest for Asian individuals receiving triple or quadruple first-line therapy based on PPIs (p < 0.05). CYP2C19 polymorphism could influence H. pylori eradication rate only in Mainland China and Japan (p < 0.05). Conclusion: PM genotype facilitates the elimination of H. pylori in Asian populations. Rabeprazole-, esomeprazole- and pantoprazole-based eradication program was less affected by the CYP2C19 polymorphism.

PMID:34414773 | DOI:10.2217/pgs-2020-0127

Front Genet. 2021 Aug 3;12:644694. doi: 10.3389/fgene.2021.644694. eCollection 2021.

ABSTRACT

Mental health problems are the leading cause of disability in Canadian workers. Medication ineffectiveness is hypothesized to increase the time to return-to-work in these workers. We assessed whether prescription changes based on pharmacogenomics profiling ( Report®) improved medication effectiveness in patients on mental health-related disability. In this retrospective cohort analyses, we assessed the impact of pharmacogenomic profiling on patient outcomes in 84 Canadian workers who were on a mental health-related disability between May 2018 and May 2019. All patients completed an informed consent form and a standard questionnaire including medical history, medications, disease symptoms, and medication side effects. Licensed pharmacists made recommendations for prescription changes in 83 patients. The main study outcome was medication effectiveness defined on a scale of 0 to 10 (0 being most effective and 10 being most ineffective) based on reported mood toward regular work tasks and medication side effects. We compared the medication effectiveness at baseline and at 3 months after the pharmacogenomics-based prescription changes. This retrospective cohort analyses included 46 patients who completed the follow-up questionnaires. Of them, 54% (n = 25) were females, 67% (n = 31) were Caucasians, and the mean age was 38 years (standard deviation [SD] = 11). The average baseline effectiveness score was 8.39 (SD =1.22). Following the prescription changes, the medication effectiveness scores significantly improved to an average of 2.30 (SD = 1.01) at 3 months of follow-up (effect size r = 0.62, p = <0.001). Pharmacogenomics could help in improving treatment outcomes in patients on mental health-related disability.

PMID:34413872 | PMC:PMC8370841 | DOI:10.3389/fgene.2021.644694

BJPsych Open. 2021 Aug 20;7(5):e153. doi: 10.1192/bjo.2021.995.

NO ABSTRACT

PMID:34412730 | DOI:10.1192/bjo.2021.995

Drug Metab Pers Ther. 2021 Mar 19;36(3):173-181. doi: 10.1515/dmpt-2020-0153.

ABSTRACT

Compared to Europe, data on genetic variation in genes transcribing drug metabolizing enzymes among Asian is limited due to ethnic diversity. Here we compare frequencies for clinically relevant single nucleotide polymorphism (SNP) commonly observed in drug metabolizing enzymes between European and Malaysian/Singaporean. Minor allele frequencies (MAF) for the indicated SNPs for European, South Asian and East Asian populations were obtained from the NCBI website (https://www.ncbi.nlm.nih.gov/snp). The SNP prevalence among Malaysian/Singaporean was characterized from gene association studies. Generally, some SNPs in CYP2D6 and CYP2C19 do not show good agreement between the two populations as to the MAF value obtained. CYP2D6*4 tends to be more common among European, whereas CYP2D6*10 is more common in Malays and Chinese among Singaporean. Regardless of different phenotype, MAF of CYP2D6*4 for Indians is similar to that seen by the European. Singaporeans show smaller MAF for CYP2C19*17 but higher CYP2C19*2 frequencies as opposed to European ones. Following growing attention to the contribution of CYP3A4/5, N-acetyltransferases (NAT2), thiopurine methyltransferase (TPMT) and uridine diphosphate glucuronosyltransferases (UGT)2B7 in predicting drug response across Europe, there are limited pharmacogenetics (PGx) studies examining the gene-drug interaction among Malaysian/Singaporean. To better understand the heterogeneity of the drug response, PGx studies for the abovementioned enzymes between ethnics in Malaysian/Singaporean should be identified.

PMID:34412170 | DOI:10.1515/dmpt-2020-0153

Clin Pharmacol Ther. 2021 Sep;110(3):529-532. doi: 10.1002/cpt.2359.

NO ABSTRACT

PMID:34412159 | DOI:10.1002/cpt.2359

Pharmacogenet Genomics. 2021 Aug 18. doi: 10.1097/FPC.0000000000000452. Online ahead of print.

ABSTRACT

OBJECTIVES: Evaluations from pharmacogenetics implementation programs at major US medical centers have reported variability in the clinical adoption of pharmacogenetics across therapeutic areas. A potential cause for this variability may involve therapeutic area-specific differences in published pharmacogenetics recommendations to clinicians. To date, however, the potential for differences in clinical pharmacogenetics recommendations by therapeutic areas from prominent US guidance sources has not been assessed. Accordingly, our objective was to comprehensively compare essential elements from clinical pharmacogenetics recommendations contained within Clinical Pharmacogenetics Implementation Consortium guidelines, US Food and Drug Administration drug labels and clinical practice guidelines from US professional medical organizations across therapeutic areas.

METHODS: We analyzed clinical pharmacogenetics recommendation elements within Clinical Pharmacogenetics Implementation Consortium guidelines, US Food and Drug Administration drug labels and professional clinical practice guidelines through 05/24/19.

RESULTS: We identified 606 unique clinical pharmacogenetics recommendations, with the most recommendations involving oncology (217 recommendations), hematology (79), psychiatry (65), cardiovascular (43) and anesthetic (37) medications. Within our analyses, we observed considerable variability across therapeutic areas within the following essential pharmacogenetics recommendation elements: the recommended clinical management strategy; the relevant genetic biomarkers; the organizations providing pharmacogenetics recommendations; whether routine genetic screening was recommended; and the time since recommendations were published.

CONCLUSIONS: On the basis of our results, we infer that observed differences in clinical pharmacogenetics recommendations across therapeutic areas may result from specific factors associated with individual disease states, the associated genetic biomarkers, and the characteristics of the organizations providing recommendations.

PMID:34412102 | DOI:10.1097/FPC.0000000000000452

Pharmacogenet Genomics. 2021 Aug 18. doi: 10.1097/FPC.0000000000000453. Online ahead of print.

ABSTRACT

Thiopurines [e.g. 6-mercaptopurine (6MP)] are essential for the cure of acute lymphoblastic leukemia (ALL) but can cause dose-limiting hematopoietic toxicity. Germline variants in drug-metabolizing enzyme genes TPMT and NUDT15 have been linked to the risk of thiopurine toxicity. However, the full spectrum of genetic polymorphism in these genes and their impact on the pharmacological effects of thiopurines remain unclear. Herein, we comprehensively sequenced the TPMT and NUDT15 genes in 685 children with ALL from the Children's Oncology Group AALL03N1 trial and evaluated their association with 6MP dose intensity. We identified 6 and 5 coding variants in TPMT and NUDT15 respectively, confirming the association at known pharmacogenetic variants. Importantly, we discovered a novel gain-of-function noncoding variants in TPMT associated with increased 6MP tolerance (rs12199316), with independent validation in 380 patients from the St. Jude Total Therapy XV protocol. Located adjacent to a regulatory DNA element, this intergenic variant was strongly associated TPMT transcription, with the variant allele linked to higher expression (P = 2.6 × 10-9). For NUDT15, one noncoding common variant, rs73189762, was identified as potentially related to 6MP intolerance. Collectively, we described pharmacogenetic variants in TPMT and NUDT15 associated with thiopurine sensitivity, providing further insights for implementing pharmacogenetics-based thiopurine individualization.

PMID:34412101 | DOI:10.1097/FPC.0000000000000453