The effect of MDR1 C3435T polymorphism on the eradication rate of H. pylori infection in PPI-based triple therapy: A meta-analysis

Effect of MDR1 C3435T and CYP2C19 genetic polymorphisms on the outcome of Helicobacter pylori eradication treatment in children with gastritis and peptic ulcer, Vietnam

BACKGROUND

Helicobacter pylori eradication therapy based on antimicrobial susceptibility in Vietnamese children currently get low efficiency. There are causes of treatment failure, among host genetic factors namely MDR1 C3435T and CYP2C19 affect the absorption and metabolism of proton pump inhibitors - a crucial component of eradication therapy. The study aimed to investigate the effect of MDR1 C3435T and CYP2C19 genetic polymorphisms on the cure rate.

METHODS

207 pediatric patients with gastritis and peptic ulcer infecting Helicobacter pylori completed the eradication therapy based on antimicrobial susceptibility with proton pump inhibitor esomeprazole. Eradication efficacy was assessed after at least 4 weeks by the urease breath test. MDR1 C3435T genetic polymorphism and CYP2C19 genotype were determined using a sequencing method based on Sanger's principle.

RESULTS

Among 207 children recruited in this study, the ratio of CYP2C19 EM, IM, and PM phenotypes was 40.1%, 46.4%, and 16.9%, respectively. The patient with MDR1 3435 C/C polymorphism accounted for 43.0%, MDR1 3435 C/T was 40.1%, and MDR1 3435T/T was 16.9%. The cure rate of Helicobacter pylori infection in patients with CYP2C19 EM genotype was 78.3%; 83.3% of those with the IM genotype, and PM genotype was 96,4% (p = 0.07). Successful eradication rates for Helicobacter pylori were 85.4%, 86.7%, and 68.6% in patients with the MDR1 3435 C/C, C/T, and T/T, respectively (p = 0.02). Multiple logistic regression analysis found that MDR1 C3435T genetic polymorphisms of patients were significant independent risk factors for treatment failure, and CYP2C19 genotype did not affect Helicobacter pylori eradication.

CONCLUSIONS

The Helicobacter pylori eradication rates by regimens based on antibiotic susceptibility and esomeprazole were not significantly different between the CYP2C19 phenotypes. The MDR1 C3435T polymorphism is one of the factors impacting Helicobacter pylori eradication results in children.

Host Genetic Determinants Associated With Helicobacter pylori Eradication Treatment Failure: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Helicobacter pylori infects approximately 50% of individuals worldwide. Successful H pylori eradication is associated with reduced risk of gastric cancer and peptic ulcer disease, among other conditions. We hypothesized that host genetic determinants, especially those affecting gastric pH, might contribute to eradication therapy failure, particularly when treatment adherence and antibiotic susceptibility are confirmed. We aimed to conduct a meta-analysis of host genetic variants associated with H pylori eradication failure.

METHODS

We searched the literature for studies comparing posttreatment H pylori eradication failure vs success (outcome) according to host genetic polymorphisms (exposure). Reference groups were defined according to genotypes (or corresponding phenotypes) hypothesized to be associated with successful eradication. We pooled estimates using a random-effects model and performed comprehensive sensitivity analyses.

RESULTS

We analyzed 57 studies from 11 countries; the vast majority analyzed CYP2C19 polymorphisms. Among individuals prescribed eradication regimens with proton pump inhibitors predominantly CYP2C19 metabolized, enhanced vs poor metabolizer phenotypes were associated with a 2.52-fold significantly higher likelihood of eradication failure and 4.44-fold significantly higher likelihood when treatment adherence and H pylori clarithromycin susceptibility (if relevant) were confirmed. There was no association between CYP2C19 variants and eradication failure if proton pump inhibitors less metabolized by or that bypass CYP2C19 metabolism were used. IL1B polymorphisms that are vs are not associated with less gastric acid suppression were associated with 1.72-fold significantly higher likelihood of eradication failure. There was no association between MDR1 polymorphisms and H pylori eradication failure. The certainty of evidence was moderate.

CONCLUSION

Based on meta-analysis, we identified host genetic polymorphisms significantly associated with H pylori eradication failure; host genetics might underlie eradication failure among treatment-adherent individuals with confirmed H pylori antibiotic susceptibility.

[Molecular genetic predictors of resistance to anti-Helicobacter pylori therapy]

In current clinical practice, there is no optimal empirical therapy for Helicobacter pylori (H. pylori) infection and there is a progressive decrease in the efficiency of classical eradication therapy (ET) regimens. The variability in the efficiency of ET in a specific patient is largely due to the heterogeneous molecular genetic mechanisms underlying the resistance of the microorganism to the components of the treatment regimens. The basis of the mechanisms for antibiotic resistance in H. pylori is mainly the point mutations in some genes, which determine alterations in the mechanisms of action of drugs, such as clarithromycin (domain V of 23S rRNA), metronidazole (rdxA, frxA), amoxicillin (pbp1A), tetracycline (16S rRNA), and levofloxacin (gyrA). The predictors of resistance to ET are also the CagA-negative status of the microorganism and the presence of the vacA s2 allele. There are a number of host genetic determinants (the CYP2C19 genotype (*1/*1, *1/*17, *17/*17) and the MDR1 3435 T/T genotype (in an Asian population)) that reduce the efficiency of ET, by altering the pharmacokinetics of proton pump inhibitors. In addition, the IL-1β-511 C/C polymorphism that affects gastric acid secretion is a predictor of the inefficiency of ET.