Pharmacogenetic Guided Opioid Therapy Improves Chronic Pain Outcomes and Comorbid Mental Health: A Randomized, Double-Blind, Controlled Study.

Interindividual variability in analgesic response is at least partly due to well-characterized polymorphisms that are associated with opioid dosing and adverse outcomes. The Clinical Pharmacogenetics Implementation Consortium (CPIC) has put forward recommendations for the CYP2D6 phenotype, but the list of studied drug-gene pairs continues to grow. This clinical trial randomized chronic pain patients (n = 60), referred from primary care to pain unit care into two opioid prescribing arms, one guided by CYP2D6, µ-opioid receptor (OPRM1), and catechol-O-methyl transferase (COMT) genotypes vs. one with clinical routine. The genotype-guided treatment reduced pain intensity (76 vs. 59 mm, p < 0.01) by improving pain relief (28 vs. 48 mm, p < 0.05), increased quality of life (43 vs. 56 mm p < 0.001), and lowered the incidence of clinically relevant adverse events (3 [1-5] vs. 1 [0-2], p < 0.01) and 42% opioid dose (35 [22-61] vs. 60 [40-80] mg/day, p < 0.05) as opposed to usual prescribing arm. The final health utility score was significantly higher (0.71 [0.58-0.82] vs. 0.51 [0.13-0.67] controls, p < 0.05) by improving sleepiness and depression comorbidity, with a significant reduction of 30-34% for headache, dry mouth, nervousness, and constipation. A large-scale implementation analysis could help clinical translation, together with a pharmaco-economic evaluation.

Advancing CYP2D6 Pharmacogenetics through a Pharmacoequity Lens.

Over 20% of US Food and Drug Administration (FDA)-approved drugs in the United States are metabolized by the hepatic enzyme cytochrome P450 2D6 (CYP2D6). The gene encoding CYP2D6 is highly polymorphic and genetic variation has been shown to impact drug response for many commonly dispensed drugs including opioids and antidepressants. Thus, it is important to understand an individual's CYP2D6 metabolizer status to optimize treatment outcomes for patients taking medications that are metabolized by this enzyme. Consequently, clinical CYP2D6 pharmacogenetic testing is being implemented by a growing number of health centers. Furthermore, clinical guidelines currently recommend adapting therapeutic regimens based on CYP2D6 genotype-informed phenotype. However, CYP2D6 genetic variation varies considerably across global populations and many allelic variants, or star alleles, are predominantly found in certain ancestral populations. Although CYP2D6 genetic variation has been extensively studied, there is still a paucity of information for many non-European populations. As has been shown for other pharmacogenes in randomized controlled trials, results from European populations cannot simply be extrapolated to other groups and, in some cases, even has the potential to cause harm. Therefore, enhanced inclusion in pharmacogenetic studies is urgently needed to increase ancestral representation, determine the extent of global CYP2D6 genetic variation (e.g., ancestry-specific variants), and determine the clinical impact of this variation on clinical treatment outcome. This review highlights knowledge gaps, challenges, and future directions in CYP2D6 pharmacogenomics through a unique pharmacoequity lens to address health inequities that hamper our ability to optimize drug therapy for improved pharmacological outcomes in diverse populations globally.

Cost-Utility Analysis of Pharmacogenetic Testing Based on CYP2C19 or CYP2D6 in Major Depressive Disorder: Assessing the Drivers of Different Cost-Effectiveness Levels from an Italian Societal Perspective.

BACKGROUND AND OBJECTIVES: Major depressive disorder (MDD) is a common and severe psychiatric disorder that has enormous economical and societal costs. As pharmacogenetics is one of the key tools of precision psychiatry, we analyze the cost-utility of test screening of CYP2C19 and CYP2D6 for patients suffering from major depressive disorder (MDD) and try to understand the main drivers that influence the cost-utility. METHODS: We developed two pharmacoeconomic nonhomogeneous Markov models to test the cost-utility, from an Italian societal perspective, of pharmacogenetic testing genetic to characterize the metabolizing profiles of cytochrome P450 (CYP) 2C19 and CYP2D6 in a hypothetical case study of patients suffering from major depressive disorder (MDD). The model considers different scenarios of adjustment of antidepressant treatment according to the patient's metabolizing profile or treatment over a period of 18 weeks. The uncertainty of model parameters is tested through both a probabilistic sensitivity analysis and a one-way deterministic sensitivity analysis, and these results are used in a post-hoc analysis to understand the main drivers of three alternative cost-effectiveness levels ("poor," "standard," and "high"). These drivers are first evaluated from an exploratory multidimensional perspective and next from a predictive perspective as the probability that a patient belongs to a specific cost-effectiveness level is estimated on the basis of a restricted set of parameters used in the original pharmacoeconomic model. RESULTS: The models for CYP2C19 and CYP2D6 indicate that screening has an incremental cost-effectiveness ratio of 60,000€ and 47,000€ per quality-adjusted life year (QALY), respectively. The probabilistic sensitivity analysis shows that the treatments are cost-effective for a 75,000€ willingness to pay (WTP) threshold in 58% and 63% of the Monte Carlo replications, respectively. The post-hoc analysis highlights the factors that allow us to clearly discriminates poor cost-effectiveness from high cost-effectiveness scenarios and demonstrates that it is possible to predict with reasonable accuracy the cost-effectiveness of a genetic test and the associated therapeutic pattern. CONCLUSIONS: Our findings suggest that screenings for both CYP2C19 and CYP2D6 enzymes for patients with MDD are cost-effective for a WTP threshold of 75,000€ per QALY, and provide relevant suggestions about the most important aspects to be further explored in clinical studies aimed at addressing the cost-effectiveness of genetic testing for patients diagnosed with MDD.

Pharmacogenetic testing among patients with depression in a US managed care population.

Actionable drug-gene pairs relevant to depression treatment include CYP2D6 and CYP2C19 with specific antidepressants. While clinical use of pharmacogenetic testing is growing, little is known about pharmacogenetic testing for depression treatment in managed care. We determined the incidence of single-gene CYP2D6 and CYP2C19 testing following a new depression episode among US managed care patients, and described characteristics and antidepressant use of patients receiving tests. We used paid medical and pharmacy claims for patients from commercial health plans in the US. For adult patients with a new depression episode from January 1, 2013 to June 30, 2018, we identified covered claims for single-gene CYP2D6 and CYP2C19 pharmacogenetic tests and antidepressant fills. Fewer than 1% (n = 1795) of the depressed cohort (n = 438,534) received a single-gene CYP2D6 or CYP2C19 test through their insurance within 365 days of their earliest depression episode. The percentage of patients who received a test nearly tripled from 0.2% in 2013 to 0.5% in 2014 before plateauing at 0.4% from 2014 to 2017. Among the patients who received a single-gene CYP2D6 or CYP2C19 test and filled an antidepressant within 365 days of their depression diagnosis, up to 30% may have had their initial antidepressant informed by the test result. Our findings describe the use of antidepressants before and after pharmacogenetic testing, which is clinically relevant as pharmacogenomic testing becomes more common in clinical practice. Our study also emphasizes the need for procedure and billing codes that capture multiple-gene panel tests to be more widely implemented in administrative databases.

[Pharmacoeconomic and pharmacogenetic aspects of the implementation of a personalized approach in the treatment of cardiac patients].

PURPOSE: To investigate the possibilities of pharmacoeconomic and pharmacogenetic factors monitoring to assess the effectiveness of treatment of a cardiological profile patients as a part of the implementation of a personalized approach. MATERIAL AND METHODS: 200 patients with arterial hypertension and CHD were examined. Pharmacotherapy was analyzed. ABC/VEN and DDD analysis, pharmacoeconomic analysis were applied. Genetic analysis of the polymorphism of the genes CYP2D6*4 and CYP2D6*10 encoding the subfamily of the cytochrome isoenzyme Р-450 was carried out. An original monitoring method was used to assess the effect of pharmacoeconomic and pharmacogenetic factors on the performance of cardiac care. RESULTS: When conducting a pharmacoeconomic analysis of cases of cardiac care, it was found that the costs of drug therapy are significant and take over 10% of the total costs. However, its effectiveness is insufficient in 58% of cases in inpatient and 37% in outpatient care. The analysis showed that there is an inverse mean correlation between gene polymorphism and clinical performance of cardiac care (r = -0.62) and a direct strong correlation between polypharmacy in pharmacotherapy, not accounting for interdrug interaction and clinical performance (r = 0.89).

Cytochrome P450-2D6: A novel biomarker in liver cancer health disparity.

Liver cancer morbidity and mortality rates differ among ethnic groups. In the United States, the burden of liver cancer in Asian Americans (AS) is higher compared to Caucasian Americans (CA). Research on liver cancer health disparities has mainly focused on environmental and socioeconomic factors yet has ignored the genotypic differences among various racial/ethnic groups. This lack of molecular level understanding has hindered the development of personalized medical approaches for liver cancer treatment. To understand the genetic heterogeneity of liver cancer between AS and CA, we performed a systematic analysis of RNA-seq data of AS and CA patients from The Cancer Genome Atlas (TCGA). We used four differential gene expression analysis packages; DESeq2, limma, edgeR, and Superdelta2, to identify the differentially expressed genes. Our analysis identified cytochrome P450-2D6 enzyme (CYP2D6) as the gene with the greatest differential expression with higher levels in AS compared to CA. To scrutinize the underlying mechanism of CYP2D6, Ingenuity Pathway Analysis (IPA) and Cytoscape were conducted and found hepatocyte nuclear factor-4α (HNF4A) and interleukin-6 (IL6) in direct association with CYP2D6. IL6 is downregulated in AS compared to CA, while HNF4A is not significantly different. Herein, we report that CYP2D6 may serve as a putative biomarker in liver cancer health disparities. Its negative association with IL6 proclaims an intricate relationship between CYP2D6 and inflammation in the ethnic differences seen in AS and CA liver cancer patients. The goal of the present study was to understand how genetic factors may contribute to the interethnic variability of liver cancer prevalence and outcomes in AS and CA patients. Identifying ethnic-specific genes may help ameliorate detection, diagnosis, surveillance, and treatments of liver cancer, as well as reduce disease-related incidence and mortality rates in the vulnerable population.

Applying an equity lens to pharmacogenetic research and translation to under-represented populations.

Since the publication of the Human Genome Project, genetic information has been used as an accepted, evidence-based biomarker to optimize patient care through the delivery of precision health. Pharmacogenetics (PGx) uses information about genes that encode proteins involved in pharmacokinetics, pharmacodynamics, and hypersensitivity reactions to guide clinical decision making to optimize medication therapy selection. Clinical PGx implementation is growing from the dramatic increase in PGx studies over the last decade. However, an overwhelming lack of genetic diversity in current PGx studies is evident. This lack of diverse representation in PGx studies will impede equitable clinical implementation through potentially inappropriate application of gene-based dosing algorithms, whereas representing a missed opportunity for identification of population specific single nucleotide variants and alleles. In this review, we discuss the challenges of studying PGx in under-represented populations, highlight two successful PGx studies conducted in non-European populations, and propose a path forward through community-based participatory research for equitable PGx research and clinical translation.

Protocol for a pharmacogenetic study of antidepressants: characterization of drug-metabolizing profiles of cytochromes CYP2D6 and CYP2C19 in a Sardinian population of patients with major depressive disorder.

The effectiveness of antidepressants shows high interindividual variability ranging from full symptomatologic remission to treatment-resistant depression. Many factors can determine the variation in the clinical response, but a fundamental role is played by genetic variation within the genes encoding for the enzymes most involved in the metabolism of antidepressant drugs: the CYP2D6 and CYP2C19 isoforms of the cytochrome P450 system. This study is poised to clarify whether the different metabolizing phenotypes related to CYP2D6 and CYP2C19 could have an impact on the clinical efficacy of antidepressants and whether the frequency of these phenotypes of metabolization shows differences in the population of Sardinian patients compared to other Caucasian populations. The sample is being recruited from patients followed-up and treated at the Psychiatric Unit of the Department of Medical Science and Public Health, University of Cagliari and the University Hospital Agency of Cagliari (Italy). The study design includes three approaches: (1) a pharmacogenetic analysis of 80 patients diagnosed with MDD resistant to antidepressant treatment compared to 80 clinically responsive or remitted patients; (2) a prospective arm (N = 30) of the study where we will test the impact of genetic variation within the CYP2D6 and CYP2C19 genes on clinical response to antidepressants and on their serum levels and (3) the assessment of the socio-economic impact of antidepressant therapies, and estimation of the cost-effectiveness of the pharmacogenetic test based on CYP genes.

Clinical implementation of preemptive pharmacogenomics in psychiatry: Τhe "PREPARE" study.

PREemptive Pharmacogenomic testing for Preventing Adverse drug REactions (PREPARE) is the first prospective, pre-emptive pharmacogenomic study conducted in Europe, within the frame of the Horizon 2020 program. It aims to determine whether implementing pre-emptive pharmacogenomics (PGx) testing of clinically relevant biomarkers, so as the dose and drug selection to be guided, will result in an overall reduction of both the occurrence and the severity of drug-genotype-associated adverse drug reactions (ADRs). To achieve that, two groups of patients will be recruited; one that will receive treatment according to standard clinical practice and one other that will receive pharmacogenomic-guided treatment. The Laboratory of Pharmacogenomics and Individualized Treatment of the University of Patras, which coordinates and represents Greece in this study, in collaboration with the Department of Psychiatry of the General University Hospital of Patras, the Department of Psychiatry of the Hospital "Attikon" and the Departments of Psychiatry of the Psychiatric Hospital of Athens "Dafni" is going to recruit 1500 psychiatric patients that are going to receive antidepressant or antipsychotic treatment. Our scientific hypothesis is that patients who receive pharmacogenomic guided drug and dose selection will experience 30% less ADRs than patients following standard care. Eligible drugs for inclusion in the PREPARE study, are those for which the clinical decision regarding drug and dose choice can be guided according to the Dutch Pharmacogenomics Working Group Guidelines (DPWG). Overall, 7 antidepressants (citalopram, escitalopram, sertraline, paroxetine, venlafaxine, clomipramine, amitriptyline) and 3 antipsychotics (haloperidol, zuclopenthixol, aripiprazole) related to 17 genetic variations in 2 genes (CYP2D6, CYP2C19) will be examined. Occurrence, severity and causality of adverse drug events (ADEs) will be assessed during monitoring, at month 1 and 3 after starting the index-drug, and at the end of each arm, by using the Common Toxicity Criteria for Adverse Events Scale (CTCAE) and the Liverpool Causality Assessment Tool (LCAT), respectively. The results of our study are expected to significantly contribute to the improvement of psychiatric patients' quality of life, by helping to provide the right drug, to the right dose in terms of efficacy, safety and cost-effectiveness.

Assessment of tramadol pharmacokinetics in correlation with CYP2D6 and clinical symptoms.

Objectives Due to lack of adequate data on tramadol kinetic in relevance of CYP2D6 toxicity, this study was designed to investigate the effect of CYP2D6 phenotype in tramadol poisoning. The saliva, urine and blood samples were taken at the admission time. Consequently, concentration of tramadol and its major metabolites were measured. Methods A pharmacokinetic and metabolic study was developed in cases of tramadol poisoned (n=96). Cases of tramadol poisoned evidenced seizure, hypertension, dizziness, nausea and vomiting symptoms participated. Results Female cases showed higher N-desmethyltramadol (M2) tramadol concentrations than male cases: in urine (40.12 ± 124.53 vs. 7.3 ± 7.13), saliva (16.91 ± 26.03 vs. 5.89 ± 7.02), and blood (1.11 ± 1.56 vs. 0.3 ± 0.38) samples. Significant correlation between blood, saliva, and urine concentrations were found (r = 0.5). Based on the metabolic ratio of O-desmethyltramadol (M1) of male (0.53 ± 0.22) and female (0.43 ± 0.26), poisoning and severe symptoms like seizure in female occurs statistically fewer (13.04%) than in male (50.6%). Assessment of CYP2D6 phenotype showed all of the participants were extensive metabolizers (EM) and their phenotype was associated with clinical symptoms. Conclusions According to our results, M1 as a high potent metabolite has an important role in toxicity and the likelihood of poisoning in people with EM phenotype. Finally, tramadol metabolic ratio may justify the cause of various symptoms in human tramadol poisoning.

The landscape of pharmacogenetic testing in a US managed care population.

PURPOSE: Little is known about how many insured patients receive pharmacogenetic testing. We describe trends of single-gene pharmacogenetic testing in a US managed care population, and demographic and clinical characteristics of patients who received a test. METHODS: We leveraged a random sample of nearly 11 million patients from a data set of paid medical and pharmacy claims to identify patients with at least one claim indicating receipt of at least one of these single-gene pharmacogenetic tests: CYP2C19, CYP2D6, CYP2C9, VKORC1, UGT1A1, and HLA class 1 typing. RESULTS: From 1 January 2013 to 30 September 2017, 5712 patients received at least one pharmacogenetic test (55% female; mean age = 43 years). The median number of tests per patient was 3 (mean = 2.7, max = 12); 54% were processed through Managed Medicare/Medicaid, while 45% were processed through commercial insurance. The total number of pharmacogenetic tests received more than doubled from 2013 (n = 1955) to 2015 (n = 4192), then decreased slightly in 2016 (n = 3946). The most common test was CYP2C19 (n = 4719), and "long-term (current) use of other medications" was the most common diagnosis. CONCLUSION: Pharmacogenetic testing through patients' insurance was low, but more than doubled from 2013 to 2016. This study highlights the need to better understand utilization patterns and insurance coverage for pharmacogenetic tests.

Pharmacogenomics: An evolving clinical tool for precision medicine.

Pharmacogenomics, ie, the study of how an individual's genomic profile influences his or her response to drugs, has emerged as a clinical tool to optimize drug therapy. Certain variants in some genes increase the risk of severe, life-threatening adverse effects from certain drugs. Integrating pharmacogenomics into clinical practice to assist in drug selection and dosing has the potential to improve the outcomes of treatment, reduce the risk of drug-induced morbidity and death, and be cost-effective.

Cost-effectiveness Analysis of CYP2D6*10 Pharmacogenetic Testing to Guide the Adjuvant Endocrine Therapy for Postmenopausal Women with Estrogen Receptor Positive Early Breast Cancer in China.

BACKGROUND: A CYP2D6 gene polymorphism is related to the effect of tamoxifen treatment in patient with estrogen-receptor positive (ER) positive breast cancer and CYP2D6*10 T/T can lead to a poor prognosis in Asian patients. Although one-off pharmacogenetic testing may optimize adjuvant endocrine therapy, testing prior to tamoxifen initiation incurs additional costs. AIM: We conducted a study to assess the cost-effectiveness of CYP2D6*10 pharmacogenetic testing to guide the adjuvant endocrine therapy compared with tamoxifen without CYP2D6*10 testing in China. METHODS: A semi-Markov model was developed to evaluate costs and health outcomes represented as quality adjusted life year (QALY) gained. Input data were obtained from the public literature. The results were expressed as incremental cost per QALY gained. A one-way deterministic sensitivity analysis explored the impact of uncertainty in the model parameters on results, and probabilistic uncertainty was assessed through a Monte Carlo probabilistic sensitivity analysis. RESULTS: In the base-case analysis, in the CYP2D6*10 testing and alternative adjuvant endocrine therapy group, the incremental total cost was US$17,966.95 and the incremental QALY was 3.582. Thus, the incremental cost-effectiveness ratio was US$5015.693 per QALY gained. Compared with a willingness-to-pay threshold of US$26,508/QALY in China, the CYP2D6*10 testing is the dominant strategy in postmenopausal women with ER-positive breast cancer in China, and the increased cost of genetic testing was completely worthwhile. The sensitivity analyses showed that the model we built was quite stable. CONCLUSION: From the perspective of the Chinese healthcare system, CYP2D6*10 pharmacogenetic testing was cost effective for postmenopausal women with ER-positive early breast cancer.

Post-marketing assessment of generic tamoxifen in Brazilian breast cancer patients.

Generic formulations of tamoxifen are commonly prescribed to oestrogen receptor-positive breast cancer patients at the Brazilian National Cancer Institute (INCA). We carried out a post-marketing surveillance of the generic tamoxifen formulation in current use at INCA, by comparing plasma concentrations of the parent drug and metabolites obtained with the generic vs the reference formulation. Thirty patients participated in an open-label, bracketed protocol, comprising 3 successive phases of 30-32 days each: the generic formulation was used in phases 1 and 3 and the reference formulation in phase 2. Two blood samples were collected in the last 4 days of each phase, for LC-MS/MS quantification of tamoxifen and metabolites in plasma. The median plasma concentrations (ng/mL) for the reference formulation were as follows: tamoxifen, 135.0 (CI 95% 114.2-155.8); endoxifen, 35.3 (30.0-40.8); and 4-hydroxytamoxifen, 4.8 (4.2-5.4). The endoxifen/tamoxifen plasma concentration ratio was 0.27 (0.21-0.25). ANOVA detected no statistically significant difference in plasma concentrations of tamoxifen, metabolites or the endoxifen/tamoxifen ratio among the three phases. The genetic component (rGC) of the CYP2D6-mediated conversion of tamoxifen into endoxifen, estimated using the repeated drug administration procedure across the three phases, was 0.87, pointing to an important component of genetic variability. In conclusion, this first post-marketing surveillance trial of oncologic generic drugs carried out in Brazilian patients verified the switchability between the reference and the generic tamoxifen formulation currently used at our institution. The adopted bracketed protocol adds confidence to this conclusion and may serve as a frame for future trials of post-marketing assessment of other generic drug products.

CYP2D6*10 pharmacogenetic-guided SERM could be a cost-effective strategy in Chinese patients with hormone receptor-positive breast cancer.

Aim: To assess the cost-effectiveness of CYP2D6*10 genetic testing for the management of Chinese women with hormone receptor-positive (HR+) breast cancer treated with selective estrogen receptor modulator. Methods: A Markov model was developed to evaluate a total expected cost and an incremental cost-effectiveness ratio (ICER). Robustness of the model was addressed in one-way analyses and probabilistic sensitivity analysis. Results: The cost of strategies of tamoxifen, toremifene without genotyping and the strategy base on CYP2D6*10 genotype were $63,879.19, $90,156.60 and $95,021.41, and the quality-adjusted life years gained are 8.1588, 12.89687 and 13.85911, respectively. The incremental cost-effectiveness ratio of the CYP2D6*10 testing versus toremifene were 5,055.74221/quality-adjusted life year, respectively. Conclusion:CYP2D6*10 pharmacogenetic-guided selective estrogen receptor modulator can be a cost-effective strategy in the Chinese patients with hormone receptor-positive breast cancer.

Projected Cost-Effectiveness for 2 Gene-Drug Pairs Using a Multigene Panel for Patients Undergoing Percutaneous Coronary Intervention.

BACKGROUND: For patients undergoing percutaneous coronary intervention, gene-drug associations exist relevant to first-line treatment options-antiplatelet agent, clopidogrel, and pain medication, tramadol. Knowledge of genotype information may allow for avoidance of adverse drug events during critical clinical windows. OBJECTIVE: This evaluation estimated cost-effectiveness associated with a multi-gene panel pre-emptively testing two genes providing CYP2C19 genotype-guided strategy for antiplatelet therapy, with CYP2D6 genotype-guided pain management, compared to single gene test for CYP2C19 with random assignment for pain treatment, and to no testing (empiric clopidogrel with random assignment for pain treatment). METHODS: Decision analysis modeling was used to project costs from a payer perspective and patient quality-adjusted life years (QALYs) from the three strategies. The model captured composite risks of major adverse cardiovascular events and pain therapy-related adverse drug events and associated utility estimates. We conducted sensitivity analyses to assess influential input parameters. RESULTS: Over 15 months, multi-gene testing was least costly and yielded more QALYs compared to both single gene and no testing; total incremental costs were $1646 lower with incremental gains of 0.04 QALYs for multi-gene compared with single gene and $11 368 lower with 0.17 QALY gains compared to no test. Base case analyses revealed multi gene was dominant compared to both single gene and no test, as it demonstrated cost savings with increased QALYs. CONCLUSIONS: For these patients, a multi-gene-guided strategy yields a favorable incremental cost-effectiveness ratio compared to the other two treatment strategies. Pre-emptively ascertaining additional gene-drug pair information can inform clinical and economic decision-making at the point of care.

Comparing PyroMark Q24 Pyrosequencing and MALDI-TOF MS for Identification of CYP2D6*10.

BACKGROUND: CYP2D6*10 is mainly responsible for the large pharmacokinetic variability of routinely administered metoprolol in middle-aged and elderly Asian patients. Utilizing an efficient method for identifying the CYP2D6*10 genotypes is clinically important for evaluating the pharmacokinetic effect of administration of metoprolol. This study attempted to evaluate the effectiveness of the two methods used to detect the rs1065852 and rs1135840 SNPs of the CYP2D6*10 gene. METHODS: Blood samples were processed for the collection of genomic DNA from 198 subjects across Chinese population, and detection of CYP2D6*10 (rs1065852 and rs1135840) was performed using the PyroMark Q24 pyrose-quencing and matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS). The discordant results were further validated with Sanger sequencing. We eventually attempted to assess some features of these two methods including reliability, rapidness, being appropriate, and cost-effectiveness. RESULTS: Genotyping of rs1065852 and rs1135840 detected by MALDI-TOF MS were concordant with those identified by PyroMark Q24 pyrosequencing in all 198 (100%) individuals. The hands-on-time and the turnaround time were shorter in the PyroMark Q24 pyrosequencing method than in the MALDI-TOF MS method for SNP of CYP2D6*10. In terms of being cost-effective and high-throughput, the MALDI-TOF MS method outperformed the PyroMark Q24 pyrosequencing method. CONCLUSIONS: CYP2D6*10 genotypes detected by PyroMark Q24 pyrosequencing and MALDI-TOF-MS showed that both methods were reliable, rapid, appropriate, and cost-effective methods. These methods are valuable for clinical applications.

Assessment of CYP2C9, CYP2C19, and CYP2D6 Polymorphisms in Allergic Patients with Chemical Sensitivity.

BACKGROUND: Self-reported chemical sensitivity (SCS) is characterized by adverse effects due to exposure to low levels of chemical substances. The clinical manifestations of SCS are similar to the allergy, and a high percentage of individuals with both diseases have been found. Various genes, especially genes of importance to the metabolism of xenobiotic compounds, have been associated with SCS. OBJECTIVES: The purpose of this study was to investigate whether allergic individuals with chemical sensitivity differed from allergic patients without chemical sensitivity with regard to the distribution of genotype and phenotype of CYP2C9, CYP2C19, and CYP2D6 polymorphisms. METHODS: A total of 180 patients were enrolled for this study. A questionnaire was employed to collect information on individual chemical sensitivity, while the Skin prick test and the PATCH test were used to verify the presence of an allergic condition against inhalants or contact allergens, respectively. For the evaluation of the CYP2C9, CYP2C19, and CYP2D6 polymorphisms, we used a strategy based on the amplification of the entire gene coupled to direct genomic DNA sequencing analysis. RESULTS: Overall, a total of 15 different CYP2C9, CYP2C19, and CYP2D6 haplotypes were identified in our population. If the 5 CYP2C9 and the 2 CYP2C19 identified alleles correspond to the previously described ones, 4 of the 8 CYP2D6 haplotypes, detected in the study group, present new SNPs combinations. These new suballeles were categorized as CYP2D6*2M Sa-lento Variant 1, CYP2D6*35B Salento Variant 2, CYP2D6*41 Salento Variant 3, and CYP2D6*4P Salento Variant 4 due to the presence of the key SNPs 2,850 C>T, 31G>A, 2,988 G>A, and 1,846 G>A, respectively. When the allergic individuals are divided into 2 groups according to their SCS score, we observed that the distribution of the CYP2D6 phenotypes was significantly different between the 2 groups. CONCLUSIONS: Our idea is that the application of the questionnaire that we have adopted has enabled us to diagnose a degree of chemical sensitivity, which results as comorbid of the allergic disease and in which a condition of poor or intermediate metabolizes for the detrimental CYP2D6 alleles, could represent a discriminant between the chemical sensitivity and the health state.

An economic model of the cost-utility of pre-emptive genetic testing to support pharmacotherapy in patients with major depression in primary care.

The pharmacokinetics of many antidepressants (tricyclic antidepressants (TCA) or selective serotonin re-uptake inhibitors (SSRI)) are influenced by the highly polymorphic CYP2D6 enzyme. Therefore, pharmacogenetics could play an important role in the treatment of depressive patients. The potential cost-utility of screening patients is however still unknown. Therefore, a Markov model was developed to compare the strategy of screening for CYP2D6 and subsequently adjust antidepressant treatment according to a patient's metabolizer profile of poor, extensive, or ultra metabolizer, with the strategy of no screening ('one size fits all' principle). Each week a patient had a probability of side effects, which was followed by dosage titration or treatment switching. After 6 weeks treatment effect was evaluated followed by treatment adjustments if necessary, with a total time horizon of the model of 12 weeks. The analysis was performed from a societal perspective. The strategy of screening compared with no screening resulted in incremental costs of €91 (95 percentiles: €39; €152) more expensive but also more effect with 0.001 quality adjusted life years (QALYs) (95 percentiles: 0.001; 0.002) gain. The incremental cost-effectiveness ratio (ICER) was therefore €77,406 per QALY gained, but varied between €22,500 and €377,500 depending on the price of screening and productivity losses. According to our model, we cannot unequivocally conclude that screening for CYP2D6 in primary care patients using antidepressants is be cost-effective, as the results are surrounded by large uncertainty. Therefore, information from ongoing studies should be used to reduce these uncertainties.