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Ranasinghe P, Sirisena N, Senadeera V, Anandagoda G, Dissanayake VHW. Diversity of pharmacogenomic variants affecting warfarin metabolism in Sri Lankans. Pharmacogenomics 2022; 23:917-923. [DOI: 10.2217/pgs-2022-0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aims: To describe the diversity of pharmacogenomic variants affecting warfarin metabolism in Sri Lankans. Materials & methods: Genotype data were filtered out from an anonymized database of 400 Sri Lankans, and minor allele frequencies (MAF) were calculated. Variants of CYP2C9, VKORC1 and CYP4F2 genes were studied. Results: Overall, CYP2C9*2 and CYP2C9*3 alleles had MAFs of 2.25% (95% CI: 0.80–3.70) and 10.38% (95% CI: 7.50–13.50), respectively. CYP2C9*11 and CYP2C9*14 alleles had MAFs of 0.13% (95% CI: 0–0.74) and 2.50% (95% CI: 0.97–4.03), respectively. MAFs of VKORC1 variants rs7294, rs9934438, rs8050894 and rs2884737 were 47.25% (95% CI: 42.36–52.14), 10.13% (95% CI: 7.28–13.22), 9.88% (95% CI: 7.06–12.94) and 4.88% (95% CI: 2.86–7.14), respectively. MAF of CYP4F2 variant rs2108622 was 45.63% (95% CI: 40.87–50.63). Conclusion: Compared with other populations, the frequencies of some studied variants were significantly different in Sri Lankans, and these are likely to account for variability in warfarin dosage requirements.
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Affiliation(s)
- Priyanga Ranasinghe
- Department of Pharmacology, Faculty of Medicine, University of Colombo, Colombo 8, Sri Lanka
| | - Nirmala Sirisena
- Department of Anatomy, Genetics and Biomedical Informatics, Faculty of Medicine, University of Colombo, Colombo 8, Sri Lanka
| | - Vidarsha Senadeera
- Department of Anatomy, Genetics and Biomedical Informatics, Faculty of Medicine, University of Colombo, Colombo 8, Sri Lanka
| | - Gayani Anandagoda
- Department of Anatomy, Genetics and Biomedical Informatics, Faculty of Medicine, University of Colombo, Colombo 8, Sri Lanka
| | - Vajira HW Dissanayake
- Department of Anatomy, Genetics and Biomedical Informatics, Faculty of Medicine, University of Colombo, Colombo 8, Sri Lanka
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Cladding Mode Fitting-Assisted Automatic Refractive Index Demodulation Optical Fiber Sensor Probe Based on Tilted Fiber Bragg Grating and SPR. SENSORS 2022; 22:s22083032. [PMID: 35459016 PMCID: PMC9032900 DOI: 10.3390/s22083032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/02/2022] [Accepted: 04/11/2022] [Indexed: 02/01/2023]
Abstract
In the paper based on surface plasmon resonance (SPR) in a tilted fiber Bragg grating (TFBG), a novel algorithm is proposed, which facilitates demodulation of surrounding refractive index (SRI) via cladding mode interrogation and accelerates calibration and measurement of SRI. Refractive indices with a tiny index step of 2.2 × 10−5 are prepared by the dilution of glucose aqueous solution for the test and the calibration of this fiber sensor probe. To accelerate the calibration process, automatic selection of the most sensitive cladding mode is demonstrated. First, peaks of transmitted spectrum are identified and numbered. Then, sensitivities of several potentially sensitive cladding modes in amplitude adjacent to the left of the SPR area are calculated and compared. After that, we focus on the amplitudes of the cladding modes as a function of a SRI, and the highest sensitivity of −6887 dB/RIU (refractive index unit) is obtained with a scanning time of 15.77 s in the range from 1520 nm to 1620 nm. To accelerate the scanning speed of the optical spectrum analyzer (OSA), the wavelength resolution is reduced from 0.028 nm to 0.07 nm, 0.14 nm, and 0.28 nm, and consequently the scanning time is shortened to 6.31 s, 3.15 s, and 1.58 s, respectively. However, compared to 0.028 nm, the SRI sensitivity for 0.07 nm, 0.14 nm, and 0.28 nm is reduced to −5685 dB/RIU (17.5% less), −5415 dB/RIU (21.4% less), and −4359 dB/RIU (36.7% less), respectively. Thanks to the calculation of parabolic equation and weighted Gauss fitting based on the original data, the sensitivity is improved to −6332 dB/RIU and −6721 dB/RIU, respectively, for 0.07 nm, and the sensitivity is increased to −5850 dB/RIU and −6228 dB/RIU, respectively, for 0.14 nm.
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Bontempi M. Semi-empirical anticoagulation model (SAM): INR monitoring during Warfarin therapy. J Pharmacokinet Pharmacodyn 2021; 49:271-282. [PMID: 34652608 DOI: 10.1007/s10928-021-09783-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 09/15/2021] [Indexed: 12/01/2022]
Abstract
The International Normalized Ratio (INR) monitoring is an essential component to manage thrombotic disease therapy. This study presents a semi-empirical model of INR as a function of time and assigned therapy (Warfarin, k-vitamin). With respect to other methodologies, this model is able to describe the INR using a limited number of parameters and is able to describe the time variation of INR described in the literature. The presented methodology showed great accuracy in model calibration [(trueness (precision)]: 0.2% (0.1%) to 1.2% (0.3%) for coagulation factors, from 5% (9%) to 9.7% (12%) for Warfarin-related parameters and 38% (40%) for K-vitamin-related parameters. The latter value was considered acceptable given the assumptions made in the model. It has two other important results: the first is that it was able to correctly estimate INR with respect to daily therapy doses taken from the literature. The second is that it introduces a single numeric semi-empirical parameter that is able to correlate INR/dose response to physiological and environmental condition of patients.
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Affiliation(s)
- Marco Bontempi
- Struttura Complessa Scienze e Tecnologie Chirurgiche, IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, I-40136, Bologna, BO, Italy.
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Using machine learning to predict anticoagulation control in atrial fibrillation: A UK Clinical Practice Research Datalink study. INFORMATICS IN MEDICINE UNLOCKED 2021. [DOI: 10.1016/j.imu.2021.100688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Non-genetic factors and polymorphisms in genes CYP2C9 and VKORC1: predictive algorithms for TTR in Brazilian patients on warfarin. Eur J Clin Pharmacol 2019; 76:199-209. [DOI: 10.1007/s00228-019-02772-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/24/2019] [Indexed: 01/06/2023]
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Algorithm for predicting low maintenance doses of warfarin using age and polymorphisms in genes CYP2C9 and VKORC1 in Brazilian subjects. THE PHARMACOGENOMICS JOURNAL 2019; 20:104-113. [PMID: 31395958 DOI: 10.1038/s41397-019-0091-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/27/2019] [Accepted: 07/18/2019] [Indexed: 01/21/2023]
Abstract
Warfarin exhibits a wide variation in dose requirements. We sought to evaluate the association of polymorphisms CYP2C9*2 (rs1799853), CYP2C9*3 (rs1075910), and VKORC1-G1639A (rs9923231) and nongenetic factors with maintenance doses of warfarin <17.5 mg/week and to create an algorithm to predict drug sensitivity. This is a retrospective cohort study including 312 patients assisted at an anticoagulation clinic in Brazil. The mean age of participants was 60.4 ± 13.5 years and 59.9% were female. The logistic regression model included: age [odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.06], genotype VKORC1 AA (OR 31.61, 95% CI 11.20-100.15) and genotype CYP2C9 2/2, 2/3 or 3/3 (OR 16.48, 95% CI 3.37-81.79). The creation of our algorithm involved warfarin-experienced patients on stable doses, identifying factors associated with drug sensitivity. The validation of this algorithm allows its use in future populations to determine the initial dose distinguishing patients with dose requirements <17.5 mg and reducing time to achieve stable doses.
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Jorgensen AL, Prince C, Fitzgerald G, Hanson A, Downing J, Reynolds J, Zhang JE, Alfirevic A, Pirmohamed M. Implementation of genotype-guided dosing of warfarin with point-of-care genetic testing in three UK clinics: a matched cohort study. BMC Med 2019; 17:76. [PMID: 30961588 PMCID: PMC6454722 DOI: 10.1186/s12916-019-1308-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/15/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Warfarin is a widely used oral anticoagulant. Determining the correct dose required to maintain the international normalised ratio (INR) within a therapeutic range can be challenging. In a previous trial, we showed that a dosing algorithm incorporating point-of-care genotyping information ('POCT-GGD' approach) led to improved anticoagulation control. To determine whether this approach could translate into clinical practice, we undertook an implementation project using a matched cohort design. METHODS At three clinics (implementation group; n = 119), initial doses were calculated using the POCT-GGD approach; at another three matched clinics (control group; n = 93), patients were dosed according to the clinic's routine practice. We also utilised data on 640 patients obtained from routinely collected data at comparable clinics. Primary outcome was percentage time in target INR range. Patients and staff from the implementation group also provided questionnaire feedback on POCT-GGD. RESULTS Mean percentage time in INR target range was 55.25% in the control group and 62.74% in the implementation group; therefore, 7.49% (95% CI 3.41-11.57%) higher in the implementation group (p = 0.0004). Overall, patients and staff viewed POCT-GGD positively, suggesting minor adjustments to allow smooth implementation into practice. CONCLUSIONS In the first demonstration of the implementation of genotype-guided dosing, we show that warfarin dosing determined using an algorithm incorporating genetic and clinical factors can be implemented smoothly into clinic, to ensure target INR range is reached sooner and maintained. The findings are like our previous randomised controlled trial, providing an alternative method for improving the risk-benefit of warfarin use in daily practice.
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Affiliation(s)
- Andrea L Jorgensen
- Department of Biostatistics, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK.
| | - Clare Prince
- The Royal Liverpool and Broadgreen University Hospitals NHS Trust and Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Gail Fitzgerald
- The Royal Liverpool and Broadgreen University Hospitals NHS Trust and Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Anita Hanson
- The Royal Liverpool and Broadgreen University Hospitals NHS Trust and Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Jennifer Downing
- Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK.,NIHR Collaboration for Leadership in Applied Health Research and Care, North West Coast, UK
| | - Julia Reynolds
- Innovation Agency, Academic Health Science Network for the North West Coast, Daresbury, Warrington, UK
| | - J Eunice Zhang
- Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK
| | - Ana Alfirevic
- Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, member of Liverpool Health Partners, Liverpool, UK
| | - Munir Pirmohamed
- MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool and The Royal Liverpool and Broadgreen University Hospitals NHS Trust, members of Liverpool Health Partners, Liverpool, UK
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Tavares LC, Marcatto LR, Santos PCJL. Genotype-guided warfarin therapy: current status. Pharmacogenomics 2018; 19:667-685. [PMID: 29701078 DOI: 10.2217/pgs-2017-0207] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Warfarin pharmacogenomics has been an extensively studied field in the last decades as it is focused on personalized therapy to overcome the wide interpatient warfarin response variability and decrease the risk of side effects. In this expert review, besides briefly summarizing the current knowledge about warfarin pharmacogenetics, we also present an overview of recent studies that aimed to assess the efficacy, safety and economic issues related to genotype-based dosing algorithms used to guide warfarin therapy, including randomized and controlled clinical trials, meta-analyses and cost-effectiveness studies. To date, the findings still present disparities, mostly because of standard limitations. Thus, further studies should be encouraged to try to demonstrate the benefits of the application of warfarin pharmacogenomic dosing algorithms in clinical practice.
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Affiliation(s)
- Letícia C Tavares
- Laboratory of Genetics & Molecular Cardiology, Heart Institute (InCor), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, SP 05403-900, Brazil
| | - Leiliane R Marcatto
- Laboratory of Genetics & Molecular Cardiology, Heart Institute (InCor), Faculdade de Medicina FMUSP, Universidade de Sao Paulo, SP 05403-900, Brazil
| | - Paulo C J L Santos
- Department of Pharmacology, Universidade Federal de Sao Paulo UNIFESP, SP 04044-020, Brazil
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Saffian SM, Duffull SB, Wright D. Warfarin Dosing Algorithms Underpredict Dose Requirements in Patients Requiring ≥7 mg Daily: A Systematic Review and Meta-analysis. Clin Pharmacol Ther 2017; 102:297-304. [PMID: 28160278 DOI: 10.1002/cpt.649] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 01/26/2017] [Accepted: 01/29/2017] [Indexed: 01/28/2023]
Abstract
There is preliminary evidence to suggest that some published warfarin dosing algorithms produce biased maintenance dose predictions in patients who require higher than average doses. We conducted a meta-analysis of warfarin dosing algorithms to determine if there exists a systematic under- or overprediction of dose requirements for patients requiring ≥7 mg/day across published algorithms. Medline and Embase databases were searched up to September 2015. We quantified the proportion of over- and underpredicted doses in patients whose observed maintenance dose was ≥7 mg/day. The meta-analysis included 47 evaluations of 22 different warfarin dosing algorithms from 16 studies. The meta-analysis included data from 1,492 patients who required warfarin doses of ≥7 mg/day. All 22 algorithms were found to underpredict warfarin dosing requirements in patients who required ≥7 mg/day by an average of 2.3 mg/day with a pooled estimate of underpredicted doses of 92.3% (95% confidence interval 90.3-94.1, I2 = 24%).
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Affiliation(s)
- S M Saffian
- School of Pharmacy, University of Otago, Dunedin, New Zealand.,Faculty of Pharmacy, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - S B Duffull
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Dfb Wright
- School of Pharmacy, University of Otago, Dunedin, New Zealand
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