Effects of CYP2C9 and VKORC1 polymorphisms on warfarin sensitivity and responsiveness during the stabilization phase of therapy

Production, characterization and biomedical potential of biosurfactants produced by haloalkaliphilic archaea from Wadi El-Natrun, Egypt

Extreme halophilic archaea that can live in high saline environments can offer potential applications in different biotechnological fields. This study delves into the fascinating field of halophilic archaea and their ability to produce biosurfactants. Some strains of haloarchaea were isolated from Wadi El-Natrun and were screened for biosurfactants production in a standard basal medium using emulsification index assay. Two strains were chosen as the potential strains for surface tension reduction. They were identified as Natrialba sp. BG1 and N3. The biosurfactants production was optimized and the produced emulsifiers were partially purified and identified using FTIR and NMR. Sequential statistical optimization, Plackett-Burman (PB) and Box-Behnken Designs (BBD) were carried out using 5 factors: oil, NaCl, casamino acids, pH, and inoculum size. The most significant factors were used for the next Response Surface Methodology experiment. The final optimal conditions for biosurfactants production were the inoculum size 2% pH 11 and NaCl 250 g/L, for Natrialba sp. BG1 and inoculum size 2.2%, pH 10 and NaCl 100 g/L for Natrialba sp. N3. The produced biosurfactants were tested for wound healing and the results indicated that Natrialba sp. BG1 biosurfactants is more efficient than Natrialba sp. N3 biosurfactants. Biosurfactants extracts were tested for their cytotoxic effects on normal cell line as well as on different cancer cells using MTT assay. The findings demonstrated that varying concentrations of the biosurfactants (31.25, 62.5, 125, 250, 500 and 1000 µg/mL) exhibited cytotoxic effects on the cell lines being tested. Additionally, the outcomes unveiled the presence of anti-inflammatory and antioxidant properties for both biosurfactants. Consequently, they could potentially serve as natural, safe, and efficient novel agents for combating cancer, promoting wound healing, and providing anti-inflammatory and antioxidant benefits.

SAMe-TT2R2 Score to Predict Time in Therapeutic Range of Vitamin K Antagonists in Asian and Non-Asian patients: A Systematic Review and Meta-analysis

BACKGROUND

Sex, age, medical history, treatment, tobacco use, and race (SAMe-TT2R2) score helps detect patients at risk of suboptimal anticoagulation control. A score above two suggests poor control; however, non-Caucasian status being assigned two points might hinder the recognition of poor control in patients of other races.

OBJECTIVE

To evaluate the SAMe-TT2R2 score's ability to predict poor anticoagulation control [defined as time in therapeutic range (TTR) < 60-70%] in Asian and non-Asian populations on vitamin K antagonists (VKAs).

METHODS

We searched PubMed, Cochrane Library, Scopus, SpringerLink, and Web of Science using the keyword "SAMe-TT2R2." Articles published before April 2022 were screened. We gathered mean TTR and diagnostic accuracy data for different SAMe-TT2R2 thresholds and conducted meta-analyses using random-effects models.

RESULTS

A total of 30 studies were included (N = 36,690). The overall mean TTR differences were - 4.88 and - 6.41 for the cutoffs of ≥ 3 and ≥ 4, respectively. For non-Asian patients, the mean TTR differences were - 3.86, - 5.12, and - 8.09 for the cutoffs ≥ 2, ≥ 3, and ≥ 4, respectively. For Asian patients, the mean TTR differences were - 3.99 and - 4.07 for the cut-offs ≥ 3 and ≥ 4, respectively. The highest positive likelihood ratio (LR+) for the Asian subgroup was 1.17 [95% confidence interval (CI): 1.06-1.28; I2 = 0%, p heterogeneity = 0.500] at cutoff ≥ 4 and for the non-Asian subgroup, at cut-off ≥ 3, the LR+ was 1.24 (95% CI 1.14-1.34; I2 = 0% p heterogeneity = 0.455). The lowest LR- was found at a lower cutoff for both races (at cutoff ≥ 3 and ≥ 2 for Asian and non-Asian subgroups, respectively). The pooled results of other accuracy parameters were modest at all cutoffs, except for the sensitivity at cutoff ≥ 3 in the Asian subgroup (83.05%).

CONCLUSION

Our study results suggest that a higher SAMe-TT2R2 score resulted in a greater reduction of TTR among Asian and all races. The accuracy parameters showed the highest sensitivity for poor TTR at the SAMe-TT2R2 cutoff of ≥ 3 for Asian patients. However, the ability to identify patients likely to have poor TTR was limited. Further research is needed to enhance the risk assessment for poor anticoagulation control with VKAs.

REGISTRATION

The protocol of this systematic review was registered in the International Prospective Register of Scientific Reviews: PROSPERO, registration number CRD42021291865.

A comprehensive survey of warfarin-induced hepatic toxicity using histopathological, biomarker, and molecular evaluation

Warfarin finds human application as anticoagulant therapy. Warfarin usage can cause liver damage and hemorrhage. Besides functioning as anticoagulant and causing continuous bleeding of pests, the mechanism of toxicity of warfarin is unknown. In this study, Wild female and male rats were administrated orally with warfarin for 18 days at 9, 18, 27.5, and 55 mg/kg, respectively. Hepatoxicity was determined by assessing, LD50, leukocyte counts, immunochemistry, histopathology, serum proteins, Western blotting, especially of markers of liver injury, such as AST, ALT & ALP, and markers of antioxidant and oxidative stress markers. Warfarin treatment decreased Nrf2 levels while it increased caspase 3, CYP2C9, COLL1A1. It caused cellular damage and fibrosis of liver. The plasma levels of markers of liver injury, AST, ALT, ALP, bilirubin and transferrin were increased. The plasma levels of albumin, IgG and antitrypsin were decreased. Warfarin treatment decreased RBC and total lymphocyte count while increasing selectively neutrophils. Warfarin exposure caused increased oxidative stress; increased LPO and decreased GSH, SOD, CAT and NO production. Oral exposure of rats with Warfarin leads to increased oxidative stress resulting into liver damage via CYP2C9 mediated by Nrf2 depletion.

Effect of MEF2A and SLC22A3-LPAL2-LPA gene polymorphisms on warfarin sensitivity and responsiveness in Jordanian cardiovascular patients

AIMS

This study aims to investigate the influence of MEF2A and SLC22A3-LPAL2-LPA polymorphisms on cardiovascular disease susceptibility and responsiveness to warfarin medication in Jordanian patients, during the initiation and maintenance phases of treatment.

BACKGROUNDS

Several candidate genes have been reported to be involved in warfarin metabolism and studying such genes may help in finding an accurate way to determine the needed warfarin dose to lower the risk of adverse drug effects, resulting in more safe anticoagulant therapy.

METHODS

The study population included 212 cardiovascular patients and 213 healthy controls. Genotyping of MEF2A and SLC22A3-LPAL2-LPA polymorphisms was conducted to examine their effects on warfarin efficiency and cardiovascular disease susceptibility using PCR-based methods.

RESULTS

One SNP (SLC22A3-LPAL2-LPA rs10455872) has been associated with cardiovascular disease in the Jordanian population, whereas the other SNPs in the MEF2A gene and SLC22A3-LPAL2-LPA gene cluster did not have any significant differences between cardiovascular patients and healthy individuals. Moreover, SLC22A3-LPAL2-LPA rs10455872 was correlated with moderate warfarin sensitivity, the other SNPs examined in the current study have not shown any significant associations with warfarin sensitivity and responsiveness.

CONCLUSION

Our data refer to a lack of correlation between the MEF2A polymorphism and the efficacy of warfarin treatment in both phases of treatment, the initiation, and maintenance phases. However, only rs10455872 SNP was associated with sensitivity to warfarin during the initiation phase. Furthermore, rs3125050 has been found to be associated with the international normalized number treatment outcomes in the maintenance phase.

Influence of polymorphisms in CYP2C9, VKORC1, MDR1 and APOE genes on the warfarin maintenance dose in Brazilian patients

Background: Polymorphisms in the CYP2C9, VKORC1, MDR1 and APOE genes may impact warfarin dose. Aim: To investigate the influence of sociodemographic, clinical factors and polymorphisms *1, *2 and *3 for CYP2C9, -1639G>A for VKORC1, 3435C>T for MDR1, and ϵ2, ϵ3 and ϵ4 for APOE genes on the mean weekly warfarin maintenance dose in adults. Methods: This cross-sectional study recruited a calculated sample of 315 patients in three anticoagulation clinics in Brazil. A model containing the variables significantly associated with warfarin dose was estimated. Results: The mean age of patients was 64.1 ± 13.1 years, with 173 (54.9%) women. Age, use of amiodarone, genotype VKORC1 GA, genotype VKORC1 AA, genotypes CYP2C9*1/*2 or *1/*3 and genotypes CYP2C9*2/*2 or *2/*3 or *3/*3 were associated with a reduced warfarin dose. Conclusion: This study pointed out factors that could impact the management of oral anticoagulation.

Association of VKORC1 and CYP2C9 single-nucleotide polymorphisms with warfarin dose adjustment in Saudi patients

OBJECTIVES

Despite its wide usage, warfarin therapy remains challenging due to its narrow therapeutic index, inter-individual response variability, and risk of bleeding. Previous reports have suggested that polymorphisms in VKORC1 and CYP2C9 genes could influence warfarin therapy. Herein, we investigated whether VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 gene polymorphisms are associated with warfarin dose adjustment and related bleeding events.

METHODS

This cross-sectional study was conducted on Saudi adults receiving warfarin for more than 1 month. Their demographics and relevant clinical data were obtained. Genotyping for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*2 genotypes was performed.

RESULTS

Patients who are homozygous for the mutant T allele VKORC1 T/T required the lowest warfarin daily maintenance dose, compared to VKORC1 C/T and VKORC1 C/C. Similarly, there was a significant reduction in warfarin daily maintenance dose among CYP2C9*1/*3 and CYP2C9*1/*2 groups compared to CYP2C9*1/*1. However, we found no significant correlation between the studied polymorphisms and warfarin-associated bleeding.

CONCLUSIONS

Similar to other populations, the VKORC1 and CYP2C9 gene polymorphisms are significantly associated with warfarin dosage in Saudi patients. The presence of at least one copy of the mutant alleles for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 is associated with a significant reduction in warfarin maintenance dose.

Characterizing the Impact of Primer-Template Mismatches on Recombinase Polymerase Amplification

Recombinase polymerase amplification (RPA) is an isothermal amplification assay that has been ubiquitously utilized in the detection of infectious agents. Like any nucleic acid amplification technology, primer-template complementarity is critical to RPA reaction success. Mismatches arising in the primer-template complex are known to impact reaction kinetics, invalidate downstream analysis, such as nucleic acid quantification, and result in false negatives if used in a diagnostic capacity. Although the impact of specific primer-template mismatches has been well characterized for techniques such as PCR, characterization remains limited for RPA. Through our study, we systematically characterize the impact of mismatches on the RPA reaction, when located in the 3'-anchor region of the primer-template complex. Our investigation identified that the nucleotides involved, as well as position of each mismatch, influence the size of the impact, with terminal cytosine-thymine and guanine-adenine mismatches being the most detrimental. The presence of some mismatch combinations, such as a penultimate cytosine-cytosine and a terminal cytosine-adenine mismatch pairing, led to complete RPA reaction inhibition. Through the successful characterization of 315 mismatch combinations, researchers can optimize their RPA assay accordingly and seek to implement RPA technology for rapid, in-field genotyping.

Association of Genetic Polymorphisms with Complications of Implanted LVAD Devices in Patients with Congestive Heart Failure: A Kazakhstani Study

The left ventricular assist device (LVAD) is one of the alternative treatments for heart failure (HF) patients. However, LVAD support is followed by thrombosis, and bleeding complications which are caused by high non-physiologic shear stress and antithrombotic/anticoagulant therapy. A high risk of complications occurs in the presence of the genotype polymorphisms which are involved in the coagulation system, hemostasis function and in the metabolism of the therapy. The aim of the study was to investigate the influence of single-nucleotide polymorphisms (SNP) in HF patients with LVAD complications. We analyzed 21 SNPs in HF patients (n = 98) with/without complications, and healthy controls (n = 95). SNPs rs9934438; rs9923231 in VKORC1, rs5918 in ITGB3 and rs2070959 in UGT1A6 demonstrated significant association with HF patients’ complications (OR (95% CI): 3.96 (1.42–11.02), p = 0.0057), (OR (95% CI): 3.55 (1.28–9.86), p = 0.011), (OR (95% CI): 5.37 (1.79–16.16), p = 0.0056) and OR (95% CI): 4.40 (1.06–18.20), p = 0.044]. Genotype polymorphisms could help to predict complications at pre- and post-LVAD implantation period, which will reduce mortality rate. Our research showed that patients can receive treatment with warfarin and aspirin with a personalized dosage and LVAD complications can be predicted by reference to their genotype polymorphisms in VKORC1, ITGB3 and UGT1A6 genes.

Association of VKORC1 and CYP2C9 single-nucleotide polymorphisms with warfarin dose adjustment in Saudi patients

OBJECTIVES

Despite its wide usage, warfarin therapy remains challenging due to its narrow therapeutic index, inter-individual response variability, and risk of bleeding. Previous reports have suggested that polymorphisms in VKORC1 and CYP2C9 genes could influence warfarin therapy. Herein, we investigated whether VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 gene polymorphisms are associated with warfarin dose adjustment and related bleeding events.

METHODS

This cross-sectional study was conducted on Saudi adults receiving warfarin for more than 1 month. Their demographics and relevant clinical data were obtained. Genotyping for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*2 genotypes was performed.

RESULTS

Patients who are homozygous for the mutant T allele VKORC1 T/T required the lowest warfarin daily maintenance dose, compared to VKORC1 C/T and VKORC1 C/C. Similarly, there was a significant reduction in warfarin daily maintenance dose among CYP2C9*1/*3 and CYP2C9*1/*2 groups compared to CYP2C9*1/*1. However, we found no significant correlation between the studied polymorphisms and warfarin-associated bleeding.

CONCLUSIONS

Similar to other populations, the VKORC1 and CYP2C9 gene polymorphisms are significantly associated with warfarin dosage in Saudi patients. The presence of at least one copy of the mutant alleles for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 is associated with a significant reduction in warfarin maintenance dose.

COX-1, COX-2 and CYP2C19 variations may be related to cardiovascular events due to acetylsalicylic acid resistance

BACKGROUND

In some stent implanted patients, cardiovascular events (CE) may occur. Acetylsalicylic acid (ASA) is routinely administered to these patients in order to prevent the occurrence of CE. CE may be related to gene variations which cause ASA resistance (AR). Therefore, it was aimed to investigate the relationship between COX-1, COX-2, CYP2C9 and CYP2C19 variations with CE due to AR.

MATERIALS AND RESULTS

Seventy-four stent implanted patients, using 100 mg of ASA per day during five years were enrolled into the study. Following stent implantation, thirty-eight patients who had a CE within five years due to AR and 36 patients without CE were enrolled in patient and control group, respectively. AR was confirmed by platelet aggregation testing. After DNA isolation from blood; COX-1, COX-2, CYP2C19 and CYP2C9 variations were investigated with real-time polymerase chain reaction. At the end of this study, heterozygous genotype of COX-1 was found statistically high in patients whereas heterozygous genotype of CYP2C19*17 was found statistically high in controls. The presence of C and G allele in COX-1 and COX-2 were found statistically high in patients, respectively. The presence of T allele in CYP2C19*17 was found statistically high in controls. Heterozygous genotype of COX-1 variation was found statistically high in patients who have AR. Additionally heterozygous genotype of CYP2C19*17 was found statistically high in patients who have low thrombosis risk.

CONCLUSIONS

COX-1 and COX-2 gene mutations may increase the risk of CE due to AR whereas CYP2C19*17 may have a protective effect in this process.

Anticoagulation Control in Different Ethnic Groups Receiving Vitamin K Antagonist for Stroke Prevention in Atrial Fibrillation

Vitamin K antagonist such as warfarin reduces the risk of stroke in atrial fibrillation (AF) patients. Since warfarin has a narrow therapeutic index, its administration needs to be regularly monitored to avoid any adverse clinical outcomes such as stroke and bleeding. The quality of anticoagulation control with warfarin therapy can be measured by using time in therapeutic range (TTR). This review focuses on the prevalence of AF, quality of anticoagulation control (TTR) and adverse clinical outcome in AF patients within different ethnic groups receiving warfarin therapy for stroke prevention. A literature search was conducted in Embase and PubMed using keywords of “prevalence,” “atrial fibrillation,” “stroke prevention,” “oral anticoagulants,” “warfarin,” “ethnicities,” “race” “time in therapeutic range,” “adverse clinical outcome,” “stroke, bleeding.” Articles published by 1st February 2020 were included. Forty-one studies were included in the final review consisting of AF prevalence (n = 14 studies), time in therapeutic range (n = 18 studies), adverse clinical outcome (n = 9 studies) within different ethnic groups. Findings indicate that higher prevalence of AF but better anticoagulation control among the Whites as compared to other ethnicities. Of note, non-whites had higher risk of strokes and bleeding outcomes while on warfarin therapy. Addressing disparities in prevention and healthcare resource allocation could potentially improve AF-related outcomes in minorities.

Polymorphism of the CYP2C9 and VKORC1 genes in patients on the public health system of a municipality in Southern Brazil

Background

Genetic factors can be responsible for part of the populational and interindividual differences observed in warfarin users.

Objectives

To identify occurrence of polymorphisms of the CYP2C9 and VKORC1 genes in patients taking warfarin and relate these profiles to their medication dosages and the Time in Therapeutic Range (TTR).

Methods

Monthly interviews were conducted for data collection. Data were collected on demographic characteristics and medications in use, especially warfarin, including reason for prescription and weekly dose. TTR was calculated as the percentage of days with international normalized ratio (INR) between 2 and 3. The CYP2C9 and VKORC1 genes were analyzed at a Human Genetics Laboratory.

Results

49 patients (74.2%) had polymorphisms of the CYP2C9 and/or VKORC1 genes; the remaining 17 (25.8%) did not have these polymorphisms. The average weekly dose of warfarin was lower among those who had a polymorphism for any of the genes compared to those who did not, with a significant difference (p = 0.035). The mean TTR was also lower among patients with polymorphism. However, the difference between the two groups was not significant for this variable (p = 0.438).

Conclusions

An association was observed between the polymorphisms and the warfarin doses taken by the patients. However, there was no association with adverse events or the time spent within the therapeutic range in this sample.

Influence of CYP2C9, VKORC1, and CYP4F2 polymorphisms on the pharmacodynamic parameters of warfarin: a cross-sectional study

BACKGROUND

Warfarin is the most commonly evaluated drug in pharmacogenetic-guided dosing studies. However, gaps remain regarding the influence of the genetic polymorphisms of CYP2C9, VKORC1, and CYP4F2 on specific pharmacodynamic parameters like the warfarin sensitivity index (WSI), prothrombin time international normalized ratio (PT-INR), and log-INR variability.

METHODS

A cross-sectional study was conducted in non-smoking adults receiving warfarin for at least 6 months. Their demographics, diagnoses, warfarin dosing regimen, concomitant drugs, PT-INR, and bleeding episodes were obtained. CYP2C9 (rs1057910-*3 and rs1799853-*2 alleles), CYP4F2 (rs2108622), and VKORC1 (rs9923231) polymorphisms were assessed using real-time polymerase chain reaction. Three genotype groups (I-III) were defined based on the combined genetic polymorphisms of CYP2C9 and VKORC1 from the FDA's recommendations. Key outcome measures included anticoagulation control, time spent in therapeutic range, stable warfarin dose, WSI, log-INR variability, and Warfarin Composite Measure (WCM).

RESULTS

The study recruited 236 patients; 75 (31.8%) carried a functional CYP2C9 variant allele, and, 143 (60.6%) had at least one T allele in CYP4F2 and 133 (56.4%) had at least one T allele in VKORC1. Groups' II and III CYP2C9 and VKORC1 genotypes were observed with reduced stable warfarin dose, increased WSI, higher log-INR variability, and increased bleeding risk. The presence of *2 or *3 allele in CYP2C9 was observed with reduced stable warfarin doses akin to the presence of T alleles in VKORC1; however, the doses increased with T alleles in CYP4F2.

CONCLUSION

The evaluated genetic polymorphisms significantly influenced all the pharmacodynamic parameters of warfarin. Evaluating CYP2C9, VKORC1, and CYP4F2 genetic polymorphisms prior to warfarin initiation is likely to optimize therapeutic response.

Variants in CDHR3, CACNAC1, and LTA Genes Predisposing Sensitivity and Response to Warfarin in Patients with Cardiovascular Disease

Introduction

Warfarin has been in use for more than 60 years; however, it has serious side effects including major bleeding. The high interpatient variability in the required dose impacts the sensitivity and responsiveness to warfarin in different patients. This study aims to assess the influence of CDHR3, CACNAC1, and LTA gene polymorphisms on the variability of warfarin dose requirements and susceptibility to coronary heart disease in the Jordanian population.

Methods

This study was conducted in the anti-coagulation clinic in Queen Alia Heart Institute in Amman, with 212 patients in total. Three SNPs were genotyped within CDHR3 (rs10270308), CACNAC1 (rs216013), and LTA (rs1041981) genes.

Results

Our findings revealed that patients with LTA polymorphism are more prone to warfarin sensitivity than others. Furthermore, carriers of the LTA polymorphism needed a lower initial dose of warfarin and are associated with less variation in doses required to achieve target INR.

Conclusion

The current study could help in understanding the role of genetic variability in warfarin dosing and matching patients to different treatment options. Clinical applications of these findings for warfarin treatment may also contribute to improving the efficacy and safety of warfarin treatment in Jordanian patients with cardiovascular disease.

The impact of CYP2C9 and VKORC1 genetic polymorphisms in anticoagulant therapy management after cardiac surgery with extracorporeal circulation

Extracorporeal circulation during cardiac surgery is characterized with increased risk for hypercoagulation because blood is exposed to foreign, nonendothelial cell surfaces. Thus, the usage of extracorporeal circulation is essentially not possible without anticoagulation. Open-heart surgery as well as many perioperative factors, such as acidosis, hypocalcemia, hypothermia, and hemodilution, might affect hemostasis and lead to coagulopathy and bleeding. A new insight into the effectiveness of anticoagulant therapy is applied to modify the dosing regimen with respect to the genetic CYP2C9 and VKORC1allelic variants. A systematic literature search was performed for VKORC1 and CYP2C9 and their association with coumarin anticoagulant therapy and bleeding risk in postoperative period of cardiac surgery with extracorporeal circulation.

Impact of PCSK9, WDR12, CDKN2A, and CXCL12 Polymorphisms in Jordanian Cardiovascular Patients on Warfarin Responsiveness and Sensitivity

Background

The main objective of this study is sought to determine the impacts of PCSK9, WDR12, CDKN2A, and CXCL12 polymorphisms on warfarin sensitivity and responsiveness in Jordanian cardiovascular patients during the initiation and stabilization phases of therapy.

Methods

This study took place at the anticoagulation clinic at Queen Alia Heart Institute (QAHI) in Jordan. DNA samples were collected from 212 cardiovascular patients and 213 healthy controls. Genomic SNPs genotyping was conducted using the MassARRAY System at the Australian Genome Research Facility.

Results

This study assessed 10 polymorphisms (rs11206510 within the PCSK9 gene, rs6725887 and rs7582720 within the WDR12 gene, rs4977574, rs10757278, and rs1333049 within the CDKN2A gene, rs2862116, rs7906426, rs1746048, and rs268322 within the CXCL12 gene) in 212 Jordanian cardiovascular patients. Carriers of CDKN2A rs1333049, rs10757278, and PCSK9 rs11206510 polymorphisms had an increased risk of resistance during the initiation phase of warfarin therapy compared to those who do not carry it, or those who are carrying one polymorphism only (P < 0.05), while carriers of CXCL12 rs7906426 polymorphism had similar increased risk but during the stabilization phase of warfarin therapy (P < 0.05).

Conclusion

Carriers of CXCL12 rs2862116 polymorphism had an increased risk to be warfarin extensive responders compared to those with no or only one polymorphism (P = 0.01). However, the presence of PCSK9 rs11206510 polymorphism affects the warfarin maintenance doses (P ˃ 0.0001).

Influence of CYP4F2, ApoE, and CYP2A6 gene polymorphisms on the variability of Warfarin dosage requirements and susceptibility to cardiovascular disease in Jordan

Cardiovascular diseases are among the leading causes of death worldwide. Many of those diseases require treatment with warfarin, an anticoagulant that has a large high inter and intra-variability in the required doses. The aim of this study is to find if there are any associations between rs2108622 of CYP4F2, rs7412 and rs405509 of ApoE, and rs1801272 of CYP2A6, and CVD and warfarin dose variability. The selected genes and their polymorphisms are involved in many GWAS associated with cardiovascular disease and variability in warfarin treatment. The study sample consisted of 212 Jordanian Cardiovascular patients and 213 healthy controls. DNA was extracted and the Mass ARRAY™ system was used to genotype four selected SNPs within three genes (CYP4F2, ApoE, and CYP2A6). Only one out of the four selected SNPs (ApoE rs7412 SNP) was found to be associated with the risk of cardiovascular disease. Also, this SNP showed significant differences in warfarin initial doses. CYP2A6 rs1801272 SNP was found to be associated with warfarin sensitivity during the initiation phase of therapy and with warfarin responsiveness and INR measurement during the stabilization phase of therapy. This study improves the current understanding of the high inter and intra-variabilities in response to warfarin, including the variety of dosing requirements and the susceptibility to cardiovascular disease in the Jordanian Arab population. Further study on a larger sample and in different ethnic groups could help in improving our understanding of warfarin's pharmacogenetics and its application in personalized medicine.

Influence of PSRC1, CELSR2, and SORT1 Gene Polymorphisms on the Variability of Warfarin Dosage and Susceptibility to Cardiovascular Disease

Background

Cardiovascular disease is one of the most common causes of morbidity and mortality worldwide. Several cardiovascular diseases require therapy with warfarin, an anticoagulant with large interindividual variability resulting in dosing difficulties. The selected genes and their polymorphisms have been implicated in several Genome-Wide Association Study (GWAS) to be associated with cardiovascular disease.

Objective

The goal of this study is to discover if there are any associations between rs646776 of PSRC1, rs660240 and rs12740374 of CELSR2, and rs602633 of SORT1 to coronary heart disease (CHD) and warfarin dose variability in patients diagnosed with cardiovascular disease undergoing warfarin therapy.

Methods

The study was directed at the Queen Alia Hospital Anticoagulation Clinic in Amman, Jordan. DNA was extracted and genotyped using the Mass ARRAY™ system, statistical analysis was done using SPSS.

Results

The study found several associations between the selected SNPs with warfarin, but none with cardiovascular disease. All 4 studied SNPs were found to be correlated to warfarin sensitivity during the stabilization phase except rs602633 and with warfarin dose variability at the initiation phase. CELSR2 SNPs also showed association with dose variability during the stabilization phase. Also, rs646776 and rs12740374 were linked to warfarin sensitivity over the initiation phase. Only rs602633 was associated with INR treatment outcomes.

Conclusion

The findings presented in this study found new pharmacogenomic associations for warfarin, that warrant further research in the field of genotype-guided warfarin dosing.

Influence of SH2B3, MTHFD1L, GGCX, and ITGB3 Gene Polymorphisms on theVariability on Warfarin Dosage Requirements and Susceptibility to CVD in the Jordanian Population

The purpose of this study was to investigate the effects of the SH2B3, MTHFD1L, GGCX, and ITGB3 gene variants on the efficacy of warfarin treatment and its effects on the risk of cardiovascular disorders in Jordanian patients. The selected genes and their polymorphisms are involved in many Genome-Wide Association Study (GWAS) associated with cardiovascular disease and the variability of warfarin therapy. The current study conducted a genetic association and pharmacogenetics study in (212) Jordanian cardiovascular patients treated with warfarin and (213) healthy controls. DNA extraction and the Mass ARRAY™ system were used to genotype ten selected polymorphisms within four genes (SH2B3, MTHFD1L, GGCX, and ITGB3). This study confirmed a genetic association of MTHFD1L rs6922269 Single Nucleotide Polymorphism (SNP) with warfarin sensitivity during the initial and stabilization phases of treatment. Moreover, this SNP showed significant differences in the initial and maintenance doses of warfarin. This study also found an association between the genetic haplotypes (AGC and GAT) within the SH2B3 gene and responsiveness to warfarin. However, possession of an MTHFD1L rs491552 variant allele was found to affect the outcome measure of the international normalized ratio (INR) during the stabilization phase of warfarin treatment. In contrast, there was no association between all selected SNPs and susceptibility to cardiovascular disorders. This study extends the current understanding of the high variability of the warfarin response, including variability in dose requirements and susceptibility to cardiovascular disease in the Jordanian-Arab population. Other studies on a larger sample and in different ethnic groups could help to better understand the pharmacogenetics of warfarin and its application in personalized medicine.

Genetic Analysis of Pharmacogenomic VIP Variants of ABCB1, VDR and TPMT Genes in an Ethnically Isolated Population from the North Caucasus Living in Jordan

Background:

Differences in individual responses to the same medications remarkably differ among populations. A number of genes that play integral roles in drug responses have been designated as very important pharmacogenes (VIP), as they are responsible for differences in drug safety, efficacy, and adverse drug reactions among certain ethnic groups. Identifying the polymorphic distribution of VIP in a range of ethnic groups will be conducive to population-based personalized medicine.

Objective:

The aim of the current study is to identify the polymorphic distribution of VIP regarding the Chechen minority group from Jordan and compare their allele frequencies with other populations.

Methods:

A total of 131 unrelated Chechen individuals from Jordan were randomly recruited for blood collection. Identification of allelic and genotypic frequencies of eleven VIP variants within the genes of interest (ABCB1, VDR and TPMT) was carried out by means of the MassARRAY®System (iPLEX GOLD).

Results:

Within ABCB1, we found that the minor allele frequencies of the rs1128503 (A: 0.43), rs2032582 (A: 0.43), rs1045642 (A: 0.43). For VDR, the minor allele frequencies of rs11568820 (T: 0.18), rs1540339 (T: 0.30), rs1544410 (T: 0.41), rs2228570 (T: 0.24), rs3782905 (C: 0.28) and rs7975232 (C: 0.45). Finally, the minor allele frequencies for the TPMT rs1142345 and rs1800460 polymorphisms were found to be (C: 0.02) and (T: 0.01), respectively.

Conclusion:

Significant differences in allelic frequencies of eleven ABCB1, VDR and TPMT VIP variants were found between Jordanian Chechens and other populations. In our study, most populations that are similar to Chechens are those from South Asian, European (Finnish) and European, including: Utah residents with Northern and Western European ancestry, Toscani in Italia, Mexican ancestry in Los Angeles and Circassian from Jordan. The level of similarity between Chechens and those populations means that they might have shared high levels of gene flow in the past. The results obtained in this study will contribute to the worldwide pharmacogenomic databases and provide valuable information for future studies and better individualized treatments.

An identification and functional evaluation of a novel CYP2C9 variant CYP2C9*62

Warfarin is the most commonly used anticoagulant in the clinical treatment of thromboembolic diseases. The dose of warfarin varies significantly within populations, and the dose is closely related to the genetic polymorphisms of the CYP2C9 and VKORC1 genes. In this study, a new CYP2C9 nonsynonymous mutation (8576C > T) was detected after the genetic screening of 162 patients took warfarin. This mutation, named as the new allele CYP2C9*62, can result in an arginine to cysteine amino acid substitution at position 125 of the CYP2C9 protein (R125C). When expressed in insect cells, the protein expression of CYP2C9.62 was significantly lower than that of the wild-type, and its metabolic activity was also significantly decreased after the addition of three typical CYP2C9 probe drugs, suggesting that the new mutant can dramatically affect the metabolism of CYP2C9 drugs in vitro.

Pharmacogenomic landscape of VIP genetic variants in Jordanian Arabs and comparison with worldwide populations

The pharmacogenomics has lately become a focal field of research that investigates the influence of genetic variations of drug-metabolizing enzymes and their receptors and downstream proteins on the interindividual variability in response to medications and adverse drug reactions. Therefore, it is significantly important to study and analyze the variations in drug response between different ethnic groups and populations. The current study aimed to detect the distribution of the genotype and allele frequencies in several very important pharmacogenetic (VIP) gene polymorphisms in the Jordanian population of Arab descent. This study involved 500 unrelated Jordanian individuals of Arab descent. A total of 65 VIP variants located within 33 candidate genes were randomly selected from the PharmGKB database and genotyped using the MassARRAY (iPLEX GOLD) system. The chi-square test was used to evaluate the significant differences of minor allele and genotype frequencies between the Jordanian and other populations including CHE, ASW, CEU, CHB, CDX, GIH, GBR, JPT, LWK, MXL, TSI, YRI, CAR, and ACB. This study revealed six variants were not in Hardy Weinberg equilibrium (HWE) (P-value > 0.05) and ten SNPs showed monomorphic features. Most of the remaining forty-nine variant frequencies were significantly different from the compared ethnic groups (P-value < 0.05). The results of this study may be helpful to develop safer treatment by applying the concept of personalized medicine based on the profile of VIP pharmacogene variants of the Jordanian population of Arab descent.

Genetic Polymorphisms of Pharmacogenes among the Genetically Isolated Circassian Subpopulation from Jordan

Several genetic variants have been identified that cause variation among different populations and even within individuals of a similar descent. This leads to interindividual variations in the optimal dose of the drug that is required to sustain the treatment efficiency. In this study, 56 single nucleotide polymorphisms (SNPs) within several pharmacogenes were analyzed in 128 unrelated subjects from a genetically isolated group of Circassian people living in Jordan. We also compared these variant distributions to other ethnic groups that are available at two databases (Genome 1000 and eXAC). Our results revealed that the distribution of allele frequencies within genes among Circassians in Jordan showed similarities and disparities when compared to other populations. This study provides a powerful base for clinically relevant SNPs to enhance medical research and future pharmacogenomic studies. Rare variants detected in isolated populations can significantly guide to novel loci involved in the development of clinically relevant traits.

Genetic risk assessment towards warfarin application: Saudi Arabia study with a potential to predict and prevent side effects

Warfarin doses are greatly affected by polymorphism altering cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1) gene. This study evaluated the prevalence of alleles (either single or double) and carriers of single nucleotide polymorphisms (SNPs) in both genotypes CYP2C9 and VKORC1 in alkharj area, Saudi Arabia and its association with warfarin use risk. Total 112 samples were collected and genotyped using FlexiGene DNA Kit for isolation and StepOnePlus Real-Time PCR System by TaqMan allelic discrimination methods. The results indicated the frequency of 11%, 8% and 45% for CYP2C9 *2 *3 and VKORC1-1639 G > A polymorphism. And as a combination genotype it was 15.18% For both CYP2C9 and VKORC1 polymorphism, 27.67% for CYP2C9 and 42.86% for VKORC1. Non-carriers rate came to be at 30.3%. According to previously published dosing changes in warfarin for polymorphism carriers (single-double-triple). The predicted warfarin doses reduction in order of 1–1.6, 2–2.9, 2.9–3.7 mg/day. It was found that 72.3% of the study population was carrier of a type of polymorphism, 15.18% for two types of polymorphisms. These findings predict changes in warfarin metabolism and eventually dosing alteration among patients on warfarin. Both genotypes (CYP2C9 and VKORC1) require different dosing of warfarin than non-carriers in order to minimize the risk of warfarin overdosing and avoidance of the drug-related problems (DRPs).