Project description:Background: Proton pump inhibitors (PPIs) are the first-line treatment for acid-related diseases. The pharmacokinetics and therapeutic efficacy of PPIs, however, are influenced by genetic factors such as variants in genes encoding drug-metabolizing enzymes (e.g., cytochrome P450 2C19 [CYP2C19]) and drug transporters. We performed a meta-analysis to evaluate the influence of CYP2C19 genotype and PPI class, PPI dose, treatment duration and clarithromycin dose on the cure rate of PPI-containing Helicobacter pylori eradication therapy. Methods: Randomized control trials (RCTs) investigating cure rates using a PPI-amoxicillin-clarithromycin regimen among different CYP2C19 genotypes through May 2021 were included. Results: A total of 25 studies (5,318 patients) were included. The overall eradication rate in the intention-to-treat analysis was 79.0% (3,689/4,669, 95% confidence interval [CI]: 77.8-80.2%), and that in CYP2C19 extensive metabolizers (EMs), intermediate metabolizer (IMs) and poor metabolizers (PMs) was 77.7% (1,137/1,464, 95% CI: 75.3-79.6%), 81.2% (1,498/1,844, 95% CI: 79.3-83.0%) and 86.8% (644/742, 95% CI: 83.9-88.9%), respectively. Meta-analysis showed that the relaTakashitive risk of failed eradication in CYP2C19 EMs compared with IMs and PMs was 1.21 (95% CI: 1.06-1.39, P = 0.006) and 1.57 (95% CI: 1.27-1.94, P < 0.001), respectively, in the fixed-effects model. The cure rate of omeprazole and lansoprazole-containing eradication regimens differed among CYP2C19 genotypes (P < 0.05), while that of rabeprazole and esomeprazole-containing regimens was similar. Conclusion: The cure rates of PPI-amoxicillin-clarithromycin H. pylori eradication regimen, especially those containing omeprazole and lansoprazole, differ among CYP2C19 genotypes. Therefore, selection of a second-generation PPI or tailored treatment may achieve higher eradication rates than first-generation PPI-amoxicillin-clarithromycin triple regimen.
Project description:BackgroundThe metabolic activation of clopidogrel is a two-step process. It has been suggested that paraoxonase-1 (PON1) is a rate-limiting enzyme in the conversion of 2-oxo- clopidogrel to an active thiol metabolite. Conflicting results have been reported in regard to (1) the association of a common polymorphism of PON1 (Q192R) with reduced rates of coronary stent thrombosis in patients taking clopidogrel and (2) its effects on platelet inhibition in patient populations of European descent.MethodsBlood samples from 151 subjects of mixed racial background with established coronary artery disease and who received clopidogrel were analyzed. Platelet aggregation was determined with light transmittance aggregometry and VerifyNow(®) P2Y12 assay. Genotyping for cytochrome P450 2C19 (CYP2C19)*2 and *3 and PON1 (Q192R) polymorphisms was performed.ResultsCarriers of CYP2C19*2 alleles exhibited lower levels of platelet inhibition and higher on-treatment platelet aggregation than noncarriers. There was no significant difference in platelet aggregation among PON1 Q192R genotypes. Homozygous carriers of the wild-type variant of PON1 (QQ192) had similar on-treatment platelet reactivity to carriers of increased-function variant alleles during maintenance clopidogrel dosing, as well as after administration of a clopidogrel 600 mg loading dose.ConclusionCYP2C19*2 allele is associated with impaired platelet inhibition by clopidogrel and high on-treatment platelet aggregation. PON1 (Q192R) polymorphism does not appear to be a significant determinant of clopidogrel response.
Project description:AimTo analyze the influence of the -31 C/T polymorphism of the interleukin-1β gene on Helicobacter pylori eradication therapy success in patients with functional dyspepsia.MethodsFunctional dyspepsia was diagnosed according to the Rome III criteria. All patients underwent upper gastrointestinal endoscopy, and gastric biopsies were obtained at screening and 12 months after randomization (last follow-up visit). Urease test and histological examination were performed to define the H. pylori status. Patients received twice-daily amoxicillin, clarithromycin and omeprazole for 10 days. Genotyping of the interleukin-1beta -31 C/T polymorphism (rs1143627) was performed using polymerase chain reaction-restriction fragment length polymorphism.ResultsOne hundred forty-nine patients received treatment with triple therapy for H. pylori eradication. Only one patient was lost to follow-up, and adherence to study medication was 94.6%. A total of 148 patients (mean age 46.08 ± 12.24 years; 81.8% women) were evaluated for the influence of the interleukin-1beta -31 C/T polymorphism on the outcome of H. pylori eradication therapy. After treatment, bacteria were eradicated in 87% of patients (129/148). Genotype frequencies of the polymorphism were as follows: CC, 38/148 (25.7%); CT, 71/148 (47.9%); and TT, 39/148 (26.4%). Successful eradication rate was 78.9%, 94.4% and 82.1% for the CC, CT and TT genotypes, respectively. The CT genotype was significantly associated with successful H. pylori eradication (p = 0.039).ConclusionThis study suggests that the CT genotype of the interleukin-1beta -31 C/T polymorphism plays a role in the successful eradication of H. pylori among patients with functional dyspepsia.
Project description:Rational selection of disease modifying anti-rheumatic drugs in the treatment of rheumatoid arthritis (RA) has many potential advantages, including rapid disease control, reduced long-term disability and reduced overall cost to the healthcare system. Inter-individual genetic differences are particularly attractive as markers to predict efficacy and toxicity, as they can be determined rapidly prior to drug selection. The aims of this study, therefore, were to investigate the association between differences in genes associated with the metabolism, clearance and efficacy of leflunomide with its cessation in a group of rheumatoid arthritis patients who were treated with an intensive contemporary, treat-to-target approach.This retrospective cohort study identified all individuals who received leflunomide and were enrolled in the Early Arthritis inception cohort at the Royal Adelaide Hospital between 2001 and July 2011. Inclusion criteria were age (>18) and a diagnosis of rheumatoid arthritis. Patients were excluded if a DNA sample was not available, if they withdrew from the cohort or if clinical data were insufficient. Subjects were followed for 12 months or until either another disease modifying antirheumatic drug was added or leflunomide was ceased. The following single nucleotide polymorphisms (SNPs) were determined: CYP2C19*2 (rs4244285), CYP2C19*17 (rs12248560), ABCG2 421C>A (rs2231142), CYP1A2*1F (rs762551) and DHODH 19C>A (rs3213422). The effects of variables on cessation were assessed with Cox Proportional Hazard models.Thirty-three of 78 (42.3%) patients ceased leflunomide due to side effects. A linear trend between cytochrome P450 2C19 (CYP2C19) phenotype and leflunomide cessation was observed, with poor and intermediate metabolizers ceasing more frequently (adjusted Hazard Ratio = 0.432 for each incremental change in phenotype, 95% CI 0.237 to 0.790, P = 0.006). Previously observed associations between cytochrome P450 1A2 (CYP1A2) and dihydro-orotate dehydrogenase (DHODH) genotype and toxicity were not apparent, but there was a trend for ATP-binding cassette sub-family G member 2 (ABCG2) genotype to be associated with cessation due to diarrhea.CYP2C19 phenotype was associated with cessation due to toxicity, and since CYP2C19 intermediate and poor metabolizers have lower teriflunomide concentrations, it is likely that they have a particularly poor risk:benefit ratio when using this drug.
Project description:Cytochrome P450 (CYP) 2C19 is a very important drug metabolizing enzyme. Although the single nucleotide polymorphisms (SNPs) of CYP2C19 G681A and G636A have been suggested that they may increase the incidence of cardiovascular events, the relationship between SNPs in CYP2C19 and cerebral ischemic stroke (CIS) are unclear. The aim of this study was to investigate the correlation between the distribution of G681A and G636A polymorphisms in CYP2C19 gene and the risk of CIS in Chinese.The peripheral blood DNA was extracted from 299 patients with CIS and 295 healthy controls. The genotyping was conducted using the polymerase chain reaction-restriction fragment length polymorphism. The sampled sequencing was applied to verify the correctness of genotyping results. Both the genotype and allele distributions were compared in patients with CIS and healthy controls.The frequencies of CYP2C19 681AA (11.7% vs. 2.7%; P?=?0.000), 636AA (4.0% vs. 0.7%; P?=?0.007), 636AG (7.0% vs. 2.2%; P?=?0.038) genotype, CYP2C19 681A (30.9% vs. 20.8%; P?=?0.000) and 636A (13.0% vs. 5.8%; P?=?0.000) allele in the CIS group are significantly higher than those in the controls. The frequencies of CYP2C19 681AA (16.7% vs. 8.6%; P?=?0.036), CYP2C19 636AA (7.0% vs. 2.2%; P?=?0.038) genotype, CYP2C19 681A (36.4% vs. 27.6%; P?=?0.023) and CYP2C19 636A (17.5% vs.10.3%; P?=?0.010) allele in the recurrent stroke group are significantly higher than those in the first onset group. Multivariate logistic regression analysis of risk factors for cerebral ischemic stroke and recurrent stroke respectively suggests that the CYP2C19 681AA genotype may be an independent risk factor for CIS (OR?=?6.179, 95% CI: 2.285?~?16.708; P?=?0.000) and recurrent stroke (OR?=?2.305, 95% CI: 1.121?~?4.743; P?=?0.023).The AA genotype and A allele of CYP2C19 G681A may be related to the occurrence and recurrence of cerebral ischemic stroke.
Project description:To identify the structural features underlying the distinct substrate and inhibitor profiles of P450 2C19 relative to the closely related human enzymes, P450s 2C8 and 2C9, the atomic structure (Protein Data Bank code 4GQS) of cytochrome P450 2C19 complexed with the inhibitor (2-methyl-1-benzofuran-3-yl)-(4-hydroxy-3,5-dimethylphenyl)methanone (Protein Data Bank chemical component 0XV) was determined to 2.87 Å resolution by x-ray crystallography. The conformation of the peptide backbone of P450 2C19 is most similar to that of P450 2C8, but the substrate-binding cavity of P450 2C8 is much larger than that of P450 2C19 due to differences in the amino acid residues that form the substrate-binding cavities of the two enzymes. In contrast, the substrate-binding cavity of P450 2C19 is much more similar in size to that of the structure of the P450 2C9 flurbiprofen complex than to that of a modified P450 2C9 or that of P450 2C8. The cavities of the P450 2C19 0XV complex and the P450 2C9 flurbiprofen complex differ, however, because the helix B-C loops of the two enzymes are dissimilar. These conformational differences reflect the effects of adjacent structural elements that interact with the B-C loops and that differ between the two enzymes. The availability of a structure for 2C19 will facilitate computational approaches for predictions of substrate and inhibitor binding to this enzyme.
Project description:BackgroundProspective evaluation of the antifungal drug, voriconazole, is needed to determine whether drug toxicity correlates with CYP2C19 genotype or serum concentrations of voriconazole or its metabolites.MethodsWe conducted a prospective study of 95 patients to determine voriconazole toxicity and its relationship to genotype and serum levels of voriconazole and its two metabolites. Efficacy was not evaluated because, in most cases, the drug was given for empirical or prophylactic therapy.ResultsHallucinations occurred in 16 patients (16.8%), visual changes in 17 (17.9%), photosensitivity in 10 (10.5%), and hepatotoxicity in 6 (6.3%). There was no correlation between photosensitivity or hepatotoxicity and levels of voriconazole or metabolites. Patients with hallucinations had higher average voriconazole levels (4.5 vs 2.5 μg/mL) but with extensive overlap. The recommended oral dose of 200 mg did not provide consistently detectable serum voriconazole levels in adults. CYP2C19 and CYP2C9 genotypes had a minor influence over levels, though the 4 patients homozygous for the 2C19*2 genotype had higher average levels for voriconazole (4.3 vs 2.5 μg/mL) and lower N-oxide levels (1.6 vs 2.5 μg/mL).ConclusionsCYP2C19 and 2C9 genotypes were not major determinants of voriconazole metabolism. No toxic serum level of voriconazole or its metabolites could be identified.
Project description:IntroductionThe Helicobacter pylori infection and cytokine-mediated inflammatory responses play significant roles in the pathogenesis of gastric cancer (GC). This study was performed to determine the association between the risk of GC and genetic polymorphisms in interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α).MethodsThe polymorphisms of IL-1β and TNF-α genes were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 290 patients who underwent endoscopy. Infection with H. pylori was diagnosed by histological analysis, rapid urease test, and PCR of gastric biopsy samples. Quantitative real-time PCR was performed to determine the relative mRNA expression levels.ResultsNo significant difference was detected in allele frequency and genotype of all studied polymorphisms between chronic gastritis (CG), GC and healthy individuals. IL-1β mRNA was down-regulated in both gastritis (relative quantification (RQ)=0.447) and the GC groups (RQ=0.151). In contrast, the expression of TNF-α was up-regulated in the GC group (RQ=2.817) compared to the gastritis group (RQ=0.861).ConclusionsThe studied single-nucleotide polymorphisms are not risk factors for development of CG and GC. However, H. pylori infection causes a huge increase in the TNF-α expression in GC patients.
Project description:Eradicating Helicobacter pylori (H. pylori) can cause an imbalance in the microbiota. Dysbiosis of the gut microbiome may produce multiple diseases and bacterial infections. The objective of this study was to investigate the influence of Helicobacter pylori (H. pylori) infection and its eradication on the composition of the oral tongue coating microbiota. A cohort of 35 participants was recruited and categorized into two groups: the H. pylori negative group (N group) consisting of 12 individuals and the H. pylori positive group (23 individuals). Within the H. pylori positive group, subjects were further stratified into the H. pylori pre-eradicated group (HPQ group) and the H. pylori eradicated group (HPH group). H. pylori positive individuals were treated with a quadruple regimen containing bismuth, and tongue coating samples were collected both prior to and following treatment. Concurrently, tongue coating samples were collected from H. pylori negative individuals. High-throughput 16S rRNA sequencing technology was employed to assess the microbial composition of the tongue coating in the N group, HPQ group, and HPH group. Pertinent clinical data were documented.Microbial diversity was found to significantly differ among the N group, HPQ group, and HPH group, as evidenced by variations in Chao1 index, Shannon index, and Partial Least Squares Discriminant Analysis (PLS-DA). The dominant bacterial phyla identified across all groups included Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, Actinobacteria, and Saccharibacteria. At the phylum level, Firmicutes exhibited higher relative abundance in the HPQ group in comparison to both the N group and HPH group. Conversely, Bacteroidetes displayed greater prevalence in the N group and HPH group. Linear Discriminant Analysis Effect Size (LEfSe) analysis indicated a higher abundance of Romboutsia, Rothia, and Turiciactor in the HPQ group. Our study revealed significant disparities in microbial diversity and richness among the three groups. Furthermore, our findings suggest a potential association between the presence of Streptococcus, Rothia and H. pylori positive individuals.