HELICOBACTER PYLORI INFECTIONS
Conditions
Keywords
Helicobacter pylori, Clarithromycin Resistance, Helicobacter pylori Infection, Real-Time PCR, qPCR, FFPE Gastric Biopsies, 23S rRNA Mutations, Gastric Biopsy, Antibiotic Resistance
Brief summary
This prospective observational study aims to evaluate the feasibility and performance of real-time PCR (qPCR) performed on formalin-fixed, paraffin-embedded (FFPE) gastric biopsies to detect Helicobacter pylori infection and clarithromycin resistance. The study will assess whether qPCR performed on tissue samples routinely collected for histological examination can reliably identify H. pylori and mutations associated with clarithromycin resistance. Results will be compared with histology, immunohistochemistry, and bacteriological PCR. The study will also assess the potential impact of qPCR results on treatment decisions and the medical-economic impact of this diagnostic strategy.This prospective observational study aims to evaluate the feasibility and performance of real-time PCR (qPCR) performed on formalin-fixed, paraffin-embedded (FFPE) gastric biopsies to detect Helicobacter pylori infection and clarithromycin resistance. The study will assess whether qPCR performed on tissue samples routinely collected for histological examination can reliably identify H. pylori and mutations associated with clarithromycin resistance. Results will be compared with histology, immunohistochemistry, and bacteriological PCR. The study will also assess the potential impact of qPCR results on treatment decisions and the medical-economic impact of this diagnostic strategy.
Detailed description
Helicobacter pylori (H. pylori) infection is a common chronic bacterial infection associated with peptic ulcer disease and gastric malignancies. Clarithromycin resistance is an important cause of treatment failure. Current recommendations support susceptibility-guided treatment based on the detection of clarithromycin resistance; however, in routine clinical practice, resistance testing remains infrequently performed. This prospective, single-center observational study will evaluate the feasibility and diagnostic performance of real-time polymerase chain reaction (qPCR) performed on formalin-fixed, paraffin-embedded (FFPE) gastric biopsies collected during routine gastroscopy. The study will investigate whether FFPE tissue samples already obtained for histopathological examination can be used to detect H. pylori and mutations in the 23S rRNA gene associated with clarithromycin resistance. Participants will be adults with suspected H. pylori infection who require gastric biopsies during gastroscopy. H. pylori infection will be confirmed by histological examination and immunohistochemistry. For participants with confirmed H. pylori infection, corresponding FFPE tissue blocks will be selected for DNA extraction and qPCR targeting mutations associated with clarithromycin resistance. The primary objective is to prospectively evaluate the feasibility and performance of qPCR on FFPE gastric biopsies for the detection of clarithromycin resistance in H. pylori in routine clinical practice. Diagnostic performance will include sensitivity and specificity for H. pylori detection and for detection of clarithromycin-resistance mutations, as well as the proportion of samples yielding exploitable results and the time required to obtain results. Secondary objectives include describing the prevalence and epidemiology of clarithromycin-resistance mutations in the study population; assessing concordance between FFPE qPCR and immunohistochemistry, particularly in cases with low bacterial load; assessing concordance between FFPE qPCR and bacteriological PCR; evaluating the potential impact of qPCR results on therapeutic management; and assessing the medical-economic impact of a clarithromycin-resistance screening strategy based on FFPE qPCR compared with empirical treatment and bacteriological PCR. The study will include approximately 250 participants. The study is prospective and monocentric and does not involve any modification of the patient's usual clinical management. Gastric biopsies will be collected during routine gastroscopy and analyzed by pathology and bacteriology according to the study protocol. The planned inclusion period is July 2026 to January 2027, with a 10-day follow-up period.
Interventions
DIAGNOSTIC_TESTq-PCR on FFPE gastric biopsies
Real-time PCR performed on formalin-fixed, paraffin-embedded (FFPE) gastric biopsy specimens to detect Helicobacter pylori and mutations associated with clarithromycin resistance.
Sponsors
Clinique Bizet
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥18 years. * Ability to provide non-opposition to participate in the study. * Participants with suspected Helicobacter pylori infection requiring gastric biopsies during gastroscopy for H. pylori assessment by histopathology and bacteriology, including clarithromycin resistance testing by PCR. * Confirmed presence of Helicobacter pylori by histological examination and immunohistochemistry.
Exclusion criteria
* Minor participants. * Adults under legal protection, guardianship or curatorship. * Refusal to participate in the study. * Recent antibiotic therapy (\<4 weeks) that may affect bacterial load. * Recent proton pump inhibitor treatment (\<2 weeks). * Insufficient tissue quantity for complementary analyses. * Poor quality fixation or preservation of samples.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diagnostic performance of q-PCR on FFPE gastric biopsies for detection of Helicobacter pylori clarithromycin resistance | Within 10 days after gastric biopsy collection | Sensitivity and specificity of q-PCR performed on formalin-fixed paraffin-embedded (FFPE) gastric biopsies for: detection of Helicobacter pylori infection (using immunohistochemistry and internal PCR positive control as reference); detection of clarithromycin resistance-associated mutations (23S rRNA gene mutations); assessment of the proportion of exploitable samples (technical success rate); turnaround time for obtaining results.Sensitivity and specificity of q-PCR performed on formalin-fixed paraffin-embedded (FFPE) gastric biopsies for: detection of Helicobacter pylori infection (using immunohistochemistry and internal PCR positive control as reference); detection of clarithromycin resistance-associated mutations (23S rRNA gene mutations); assessment of the proportion of exploitable samples (technical success rate); turnaround time for obtaining results. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Prevalence of clarithromycin resistance in Helicobacter pylori infection | Within 10 days after gastric biopsy collection | Prevalence of clarithromycin resistance-associated mutations according to age, sex, clinical indication and clinical setting. |
| Concordance between q-PCR FFPE and immunohistochemistry results | Within 15 days after gastric biopsy collection | Agreement between q-PCR performed on FFPE gastric biopsies and immunohistochemistry results, particularly in cases with low bacterial load. |
| Concordance between q-PCR FFPE and bacteriological PCR results | Within 15 days after gastric biopsy collection | Agreement between q-PCR performed on FFPE gastric biopsies and reference PCR performed on bacteriological samples (and culture when available). |
| Impact of q-PCR results on therapeutic management | Within 15 days after inclusion and availability of laboratory results | Proportion of participants whose treatment strategy is modified based on q-PCR results, including prescription of a treatment guided by clarithromycin susceptibility profile. |
| Medical-economic impact of q-PCR FFPE strategy | Through study completion, an average of 12 months | Comparison of costs between q-PCR FFPE strategy and current empirical or bacteriological PCR-based strategies, including cost per adapted treatment and cost per avoided therapeutic failure. |
Countries
France
Contacts
CONTACTBouchra BENKESSOU
PRINCIPAL_INVESTIGATORDr Michaël Lévy
Clinique Bizet
Outcome results
None listed