An Exploratory Association Analysis of ABCB1 rs1045642 and ABCB1 rs4148738 with Non-Major Bleeding Risk in Atrial Fibrillation Patients Treated with Dabigatran or Apixaban

Gene polymorphism as a cause of hemorrhagic complications in patients with non-valvular atrial fibrillation treated with oral vitamin K-independent anticoagulants

Atrial fibrillation (AF) accounts for 40% of all cardiac arrhythmias and is associated with a high risk of stroke and systemic thromboembolic complications. Dabigatran, rivaroxaban, apixaban, and edoxaban are direct oral anticoagulants (DOACs) that have been proven to prevent stroke in patients with non-valvular AF. This review summarizes the pharmacokinetics, pharmacodynamics, and drug interactions of DOACs, as well as new data from pharmacogenetic studies of these drugs. This review is aimed at analyzing the scientific literature on the gene polymorphisms involved in the metabolism of DOACs. We searched PubMed, Cochrane, Google Scholar, and CyberLeninka (Russian version) databases with keywords: 'dabigatran', 'apixaban', 'rivaroxaban', 'edoxaban', 'gene polymorphism', 'pharmacogenetics', 'ABCB1', 'CES1', 'SULT1A', 'ABCG2', and 'CYP3A4'. The articles referred for this review include (1) full-text articles; (2) study design with meta-analysis, an observational study in patients taking DOAC; and (3) data on the single-nucleotide polymorphisms and kinetic parameters of DOACs (plasma concentration), or a particular clinical outcome, published in English and Russian languages during the last 10 years. The ages of the patients ranged from 18 to 75 years. Out of 114 reviewed works, 24 were found eligible. As per the available pharmacogenomic data, polymorphisms affecting DOACs are different. This may aid in developing individual approaches to optimize DOAC pharmacotherapy to reduce the risk of hemorrhagic complications. However, large-scale population studies are required to determine the dosage of the new oral anticoagulants based on genotyping. Information on the genetic effects is limited owing to the lack of large-scale studies. Uncovering the mechanisms of the genetic basis of sensitivity to DOACs helps in developing personalized therapy based on patient-specific genetic variants and improves the efficacy and safety of DOACs in the general population.

Genetic variants of ABCB1 and CES1 genes on dabigatran metabolism in the Kazakh population

Background

Allelic variants of genes encoding enzymes of the esterase system (CES1) and P-glycoprotein (ABCB1) can change the metabolism and pharmacokinetics of dabigatran. Therefore, they act as determining factors in the development of side effects, especially bleeding. We analyzed the genotype-phenotype relationship of ABCB1 (rs1045642, rs4148738, rs2032582, and rs1128503) and CES1 (rs8192935, rs71647871, and rs2244613) polymorphisms in patients with atrial fibrillation who had been treated with dabigatran.

Methods

A total of 150 patients were recruited for this study. TaqMan technology was used for SNP genotyping.

Results

Patients with the rs2244613 GG genotype had a lower concentration (55.27 ± 34.22 ng/ml) compared to those with the TT genotype (63.33 ± 52.25 ng/ml) (additive model, P = 0.000). Individuals with the rs8192935 AA genotype had a lower concentration (52.72 ± 30.45 ng/ml) compared to those with the GG genotype (79.78 ± 57 ng/ml) (additive model, P = 0.001). The APTT values among the different genotypes of the ABCB1 SNPs, rs4148738 and rs1045642, were significantly different (P = 0.035 and P = 0.024, respectively).

Conclusion

Our research demonstrates that the CES1 polymorphisms, rs8192935 and rs2244613, are associated with the pharmacodynamics and pharmacokinetics of dabigatran in the Kazakh subpopulation.

Personalizing Direct Oral Anticoagulant Therapy for a Diverse Population: Role of Race, Kidney Function, Drug Interactions, and Pharmacogenetics

Oral anticoagulants (OACs) are commonly used to reduce the risk of venous thromboembolism and the risk of stroke in patients with atrial fibrillation. Endorsed by the American Heart Association, American College of Cardiology, and the European Society of Cardiology, direct oral anticoagulants (DOACs) have displaced warfarin as the OAC of choice for both conditions, due to improved safety profiles, fewer drug-drug and drug-diet interactions, and lack of monitoring requirements. Despite their widespread use and improved safety over warfarin, DOAC-related bleeding remains a major concern for patients. DOACs have stable pharmacokinetics and pharmacodynamics; however, variability in DOAC response is common and may be attributed to numerous factors, including patient-specific factors, concomitant medications, comorbid conditions, and genetics. Although DOAC randomized controlled trials included patients of varying ages and levels of kidney function, they failed to include patients of diverse ancestries. Additionally, current evidence to support DOAC pharmacogenetic associations have primarily been derived from European and Asian individuals. Given differences in genotype frequencies and disease burden among patients of different biogeographic groups, future research must engage diverse populations to assess and quantify the impact of predictors on DOAC response. Current under-representation of patients from diverse racial groups does not allow for proper generalization of the influence of clinical and genetic factors in relation to DOAC variability. Herein, we discuss factors affecting DOAC response, such as age, sex, weight, kidney function, drug interactions, and pharmacogenetics, while offering a new perspective on the need for further research including frequently excluded groups.

Effect of Genotype on the Pharmacokinetics and Bleeding Events of Direct Oral Anticoagulants: A Systematic Review and Meta-analysis

This meta-analysis aimed to investigate the effect of the genotype on the pharmacokinetics and bleeding events of direct oral anticoagulants (DOACs) and comprehensively searched electronic databases. Weighted mean difference (WMD) was used to assess the kinetic indicators, odds ratio, and 95% confidence interval (CI) were used to calculate the clinical outcomes. Thirteen articles with 1543 participants were finally included in this study. The peak concentration (C_max ) and area under the plasma concentration-time curve from time 0 to infinity of individuals with the ABCB1 rs 1045642 CT + TT were higher than that of the CC (WMD = -31.9, 95% CI [-49.94, -12.24], P = .02; WMD = -79.97, 95%CI [-152.38 to -7.56], P = .03, I² = 0). The C_max of individuals with mutated genes in ABCB1 2677-3435 is higher than that the wild type (WMD = -19.20, 95%CI [36.62 to -1.79], P = .03, I² = 0). Carriers of the CYP3A5 rs776746 GG genotype had a higher C_max than the GA gene (WMD = -51.22, 95%CI [-92.26 to -10.19], P = .01, I² = 0). Bleeding events were more common in the CES1 rs 2244613 AA + AC than in the CC (odds ratio, 2.62, 95%CI [1.06, 6.47], P = .04; I² = 0). The C_max of DOACs was affected by individuals with ABCB1 rs 1045642, ABCB1 2677-343, and cytochrome P450 3A5 rs 776746. Carriers of the ABCB1 rs 1045642 affected the change of area under the plasma concentration-time curve from time 0 to infinity of DOACs. Bleeding events were affected by CES1 rs 2244613.

Eight pharmacokinetic genetic variants are not associated with the risk of bleeding from direct oral anticoagulants in non-valvular atrial fibrillation patients

Background: Atrial fibrillation (AF) is the leading cause of ischemic stroke and treatment has focused on reducing this risk through anticoagulation. Direct Oral Anticoagulants (DOACs) are the first-line guideline-recommended therapy since they are as effective and overall safer than warfarin in preventing AF-related stroke. Although patients bleed less from DOACs compared to warfarin, bleeding remains the primary safety concern with this therapy. Hypothesis: Genetic variants known to modify the function of metabolic enzymes or transporters involved in the pharmacokinetics (PK) of DOACs could increase the risk of bleeding. Aim: To assess the association of eight, functional PK-related single nucleotide variants (SNVs) in five genes (ABCB1, ABCG2, CYP2J2, CYP3A4, CYP3A5) with the risk of bleeding from DOACs in non-valvular AF patients. Methods: A retrospective cohort study was carried out with 2,364 self-identified white non-valvular AF patients treated with either rivaroxaban or apixaban. Genotyping was performed with Illumina Infinium CoreExome v12.1 bead arrays by the Michigan Genomics Initiative biobank. The primary endpoint was a composite of major and clinically relevant non-major bleeding. Cox proportional hazards regression with time-varying analysis assessed the association of the eight PK-related SNVs with the risk of bleeding from DOACs in unadjusted and covariate-adjusted models. The pre-specified primary analysis was the covariate-adjusted, additive genetic models. Six tests were performed in the primary analysis as three SNVs are in the same haplotype, and thus p-values below the Bonferroni-corrected level of 8.33e-3 were considered statistically significant. Results: In the primary analysis, none of the SNVs met the Bonferroni-corrected level of statistical significance (all p > 0.1). In exploratory analyses with other genetic models, the ABCB1 (rs4148732) GG genotype tended to be associated with the risk of bleeding from rivaroxaban [HR: 1.391 (95%CI: 1.019-1.900); p = 0.038] but not from apixaban (p = 0.487). Conclusion: Eight functional PK-related genetic variants were not significantly associated with bleeding from either rivaroxaban or apixaban in more than 2,000 AF self-identified white outpatients.

The impact of ABCB1 and CES1 polymorphisms on the safety of dabigatran in patients with non-valvular atrial fibrillation

Background

This study aimed to analyze associations between genetic variants and plasma concentrations along with clinical outcomes in dabigatran in patients with non-valvular atrial fibrillation (NVAF).

Methods

We conducted a prospective study and enrolled NVAF patients treated with dabigatran in the real world. A total of 86 patients treated with 110 mg DE twice daily were recruited for this study. Blood samples were obtained from each patient and used for genotyping and determination of plasma dabigatran concentration. All bleeding and thromboembolic complications were recorded during the 1.5 years of follow-up.

Results

Eighty-three patients provided samples at the trough plasma level of dabigatran, and 58 patients provided samples at the peak plasma level of dabigatran. There was a significant association between the CES1 SNP rs8192935 and trough plasma concentrations of dabigatran (P = 0.013). Our results showed that the CES1 SNP rs8192935 significantly influenced dabigatran trough concentrations in the Chinese population, and carriers of the G allele had increased trough plasma concentrations of dabigatran compared to noncarriers. The ABCB1 SNP c.2482-2236G > A (rs4148738) was associated with major bleeding events in the addictive model (P = 0.046, OR = 3.29) and dominant model (P = 0.040, OR = 8.17). Additionally, the ABCB1 SNP c.3435 C > T (rs1045642) was associated with the incidence of major bleeding events in the addictive model (P = 0.043, OR = 3.34) and dominant model (P = 0.046, OR = 7.77). However, no significant associations were found between all the SNPs and the incidence of minor bleeding events.

Conclusion

Our results indicated that the CES1 polymorphism rs8192935 was associated with trough plasma concentrations of dabigatran. Carriers of the G allele had increased trough plasma concentrations of dabigatran compared to noncarriers. The ABCB1 polymorphisms rs4148738 and rs1045642 were associated with an increased risk for major bleeding events for the first time in a Chinese population.

Pharmacogenetics of Bleeding and Thromboembolic Events in Direct Oral Anticoagulant Users

This study aimed to analyze associations between genetic variants and the occurrence of clinical outcomes in dabigatran, apixaban, and rivaroxaban users. This was a retrospective real-world study linking genotype data of three Finnish biobanks with national register data on drug dispensations and healthcare encounters. We investigated several single-nucleotide variants (SNVs) in the ABCG2, ABCB1, CES1, and CYP3A5 genes potentially associated with bleeding or thromboembolic events in direct oral anticoagulant (DOAC) users based on earlier research. We used Cox regression models to compare the incidence of clinical outcomes between carriers and noncarriers of the SNVs or haplotypes. In total, 1,806 patients on apixaban, dabigatran, or rivaroxaban were studied. The ABCB1 c.3435C>T (p.Ile1145=, rs1045642) SNV (hazard ratio (HR) 0.42, 95% confidence interval (CI), 0.18-0.98, P = 0.044) and 1236T-2677T-3435T (rs1128503-rs2032582-rs1045642) haplotype (HR 0.44, 95% CI, 0.20-0.95, P = 0.036) were associated with a reduced risk for thromboembolic outcomes, and the 1236C-2677G-3435C (HR 2.55, 95% CI, 1.03-6.36, P = 0.044) and 1236T-2677G-3435C (HR 5.88, 95% CI, 2.35-14.72, P < 0.001) haplotypes with an increased risk for thromboembolic outcomes in rivaroxaban users. The ABCB1 c.2482-2236G>A (rs4148738) SNV associated with a lower risk for bleeding events (HR 0.37, 95% CI, 0.16-0.89, P = 0.025) in apixaban users. ABCB1 variants are potential factors affecting thromboembolic events in rivaroxaban users and bleeding events in apixaban users. Studies with larger numbers of patients are warranted for comprehensive assessment of the pharmacogenetic associations of DOACs and their relevance for clinical practice.

Effects of the ABCB1 c.3435C>T (rs1045642) Polymorphism on Heat Pain Perception in Opioid-Free Adults With Chronic Pain

BACKGROUND

The adenosine triphosphate-binding cassette, subfamily B, member 1 gene (ABCB1) encodes P-glycoprotein (P-gp) that influences the intracellular transport of solutes including endogenous opioid peptides. The primary objective of this study was to determine the effects of the ABCB1 polymorphism c.3435C>T (rs10454642) on heat pain (HP) perception in a group of opioid-free adults with chronic pain.

METHODS

Opioid-free adults with chronic pain consecutively admitted to a pain rehabilitation program comprised the study cohort (N = 134). Individuals were genotyped for the c.3435C>T (rs10454642) polymorphism. The polymorphism was analyzed with nonparametric tests using a dominant (cytosine-cytosine [CC] versus cytosine-thymine [CT] + thymine-thymine [TT]) and recessive (CC + CT versus TT) model of allele effects. Quantitative sensory testing was performed using the Computer Aided Sensory Evaluator IV system.

RESULTS

The distribution of genotypes was 22% (N = 29) for CC, 45% (N = 60) for CT, and 33% (N = 45) for TT (Hardy-Weinberg, P > .1). A significant association was observed between the recessive model and HP threshold. Standardized values of HP threshold were significantly greater in the TT group than the CC + CT group (median difference, -0.77; 95% confidence interval [CI], -1.49 to -0.23; P = .005), and the effect size estimate was small (Cliff delta = 0.30). In the dominant model, no significant difference in HP threshold was observed between the CC and CT + TT groups (median difference, -0.45; 95% CI, -1.15 to 0.00; P = .108).

CONCLUSIONS

These results posit that the efflux of endogenous opioid peptides is reduced in individuals with the TT genotype due to lower expression of P-gp, which, in turn, results in higher HP threshold. This study contributes to the emerging understanding of how the ABCB1 c.3435C>T polymorphism contributes to pain perception in opioid-free adults with chronic pain and provides the foundation for investigating the potential effects of this polymorphism on the clinical course of chronic pain.