Gastric String Test Combined With a Rapid Antigen Assay for Helicobacter Pylori Detection

November 1, 2026 updated by: Fu Jen Catholic University Hospital

A Pilot Study Evaluating a Novel Minimally Invasive String-test and Rapid Antigen Assay for Helicobacter Pylori Detection

This single-center, open-label, prospective pilot study aims to evaluate the feasibility, safety, and preliminary diagnostic performance of a minimally invasive gastric string sampling device combined with a rapid antigen assay for the detection of Helicobacter pylori infection.

A total of 40 participants with documented ^13C-urea breath test (UBT) results will be enrolled, including 30 UBT-positive and 10 UBT-negative participants. All participants will undergo gastric mucus collection using a disposable string sampling device, followed by H. pylori rapid antigen testing.

The primary objective is to assess the diagnostic sensitivity and specificity of the investigational test using ^13C-UBT as the reference standard. The secondary objective is to explore the correlation between the semi-quantitative test-line (T-line) color intensity of the rapid antigen assay and the corresponding UBT delta-over-baseline (DOB) values.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Background and Rationale

Helicobacter pylori infection is a major cause of chronic gastritis, peptic ulcer disease, and gastric cancer. Commonly used non-invasive diagnostic methods include the ^13C-urea breath test (UBT) and stool antigen testing. Although these methods are widely used, stool-based testing requires specimen collection and handling, while UBT generally requires specialized analytical equipment.

A minimally invasive gastric string sampling device may provide an alternative approach for obtaining gastric specimens without conventional upper gastrointestinal endoscopy. Combining this sampling method with a rapid antigen assay may offer a convenient approach for H. pylori detection. However, the diagnostic performance of this combination using string-collected gastric mucus has not yet been established.

Study Design

This is a single-center, prospective, single-group pilot diagnostic accuracy study conducted at Fu Jen Catholic University Hospital, Taiwan.

An enriched enrollment strategy will be adopted to include 30 participants with positive UBT results and 10 participants with negative UBT results. All participants will undergo the same investigational procedure, and their previously obtained ^13C-UBT results will serve as the reference standard for diagnostic comparison.

Investigational Procedure

The investigational procedure combines two medical devices:

  1. Disposable Gastric Specimen Collection String: A minimally invasive gastric sampling device distributed by POCT Biotech Co., Ltd. (CE-certified, CE No. 6976663940137), used to collect gastric mucus specimens.
  2. Helicobacter pylori Rapid Antigen Test: A rapid antigen assay manufactured by Strong Biotech Co., Ltd. (Taiwan Food and Drug Administration Medical Device License No. 007277), used to detect H. pylori antigens in the collected specimens.

The use of string-collected gastric mucus with this rapid antigen assay represents an investigational application. Results obtained from this procedure will be used exclusively for research purposes and will not guide clinical diagnosis or treatment decisions.

Study Procedures

Participants will fast overnight before the study procedure. Each participant will swallow a disposable gastric specimen collection capsule with approximately 250 mL of water. After the capsule dissolves, the attached string will remain in the stomach for approximately 60 minutes to absorb gastric mucus.

The string will subsequently be retrieved by trained study personnel and immersed in the designated antigen extraction buffer. The extracted specimen will then be applied to the H. pylori rapid antigen test cassette, and the result will be interpreted after approximately 3-5 minutes.

In addition to qualitative interpretation, two independent investigators blinded to the participants' UBT results will assess the test-line (T-line) color intensity using a standardized reference chart, assigning a semi-quantitative score ranging from 0 to 4.

Safety Monitoring

Participant discomfort during capsule swallowing, gastric retention, and string retrieval will be evaluated using a Visual Analog Scale (VAS).

Potential procedure-related adverse events, including nausea, gagging, throat discomfort, mucosal irritation or injury, bleeding, and difficulty retrieving the string, will be monitored and documented. Clinically significant adverse events will be managed according to institutional clinical practice, and serious adverse events will be reported to the Institutional Review Board in accordance with applicable regulations.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Taiwan
    • Taiwan
      • New Taipei City, Taiwan, Taiwan, 24352
        • Fu Jen Catholic University Hospital
        • Contact:
        • Principal Investigator:
          • Yu-tse Chiu, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Adults aged 18-75 years.
  2. Completed a 13C-urea breath test (UBT) within 28 days prior to enrollment, with documented test results.
  3. Able to understand the study procedures and willing to provide written informed consent.

Exclusion Criteria:

  1. History of dysphagia, esophageal stricture, or gastrointestinal obstruction.
  2. Use of antibiotics, bismuth-containing agents, or proton pump inhibitors (PPIs) within 4 weeks prior to enrollment, as these medications may affect H. pylori antigen detection.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: HP String Test With Rapid Antigen Assay
Diagnostic test: HP String Test With Rapid Antigen Assay

Gastric mucus collection using a minimally invasive string test followed by Helicobacter pylori rapid antigen testing. The investigational test results will be compared with the participants' existing ^13C-UBT results as the reference standard to evaluate diagnostic agreement and preliminary diagnostic accuracy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diagnostic Sensitivity and Specificity of the HP String Test With Rapid Antigen Assay
Time Frame: At the study visit (approximately 1-2 hours after initiation of the string test procedure)

Diagnostic sensitivity and specificity of the gastric string test combined with a rapid antigen assay for detecting Helicobacter pylori infection, using the ^13C-urea breath test (UBT) as the reference standard (DOB ≥4.0 indicating a positive result and DOB <4.0 indicating a negative result).
At the study visit (approximately 1-2 hours after initiation of the string test procedure)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation Between T-Line Color Intensity and ^13C-UBT DOB Values
Time Frame: At the study visit (approximately 1-2 hours after initiation of the string test procedure)

The correlation between the test-line (T-line) color intensity of the gastric string test combined with a rapid antigen assay, graded on a standardized 0-4 ordinal scale, and the corresponding ^13C-urea breath test (UBT) delta-over-baseline (DOB) values will be assessed.
At the study visit (approximately 1-2 hours after initiation of the string test procedure)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Fu Jen Catholic University Hospital

Collaborators

SUPREME ELECTRONICS CO., LTD.
POCT BIOTECHNOLOGY CO., LTD.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 1, 2026

Primary Completion (Estimated)

March 1, 2027

Study Completion (Estimated)

March 1, 2027

Study Registration Dates

First Submitted

October 25, 2026

First Submitted That Met QC Criteria

October 25, 2026

First Posted (Actual)

October 30, 2026

Study Record Updates

Last Update Posted (Actual)

November 4, 2026

Last Update Submitted That Met QC Criteria

November 1, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FJUH115665

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data (IPD) will not be shared with external researchers to protect participant confidentiality and comply with institutional data protection policies. Only aggregated study results and findings published in scientific journals will be made available.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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