An interventional study of HP String Test With Rapid Antigen Assay in Helicobacter Pylori, sponsored by Fu Jen Catholic University Hospital. Not yet recruiting at 1 site in Taiwan. Open to participants aged 18 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Fu Jen Catholic University Hospital · Not applicable, Interventional, and Diagnostic
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.
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:
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.
1,055 studies on the registry are indexed under Hypersensitivity; 149 are open to participants now.
This study's planned enrollment of 40 is below the median of 73 across 691 interventional studies indexed under Hypersensitivity.
Browse Hypersensitivity studies →Fu Jen Catholic University Hospital is the lead sponsor of 33 studies on the registry; 18 are open to participants now.
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Exclusion Criteria:
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You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Diagnostic Sensitivity and Specificity of the HP String Test With Rapid Antigen Assay
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).
Time frame: At the study visit (approximately 1-2 hours after initiation of the string test procedure)
Correlation Between T-Line Color Intensity and ^13C-UBT DOB Values
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.
Time frame: At the study visit (approximately 1-2 hours after initiation of the string test procedure)
Plan to share: No — 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.
No publications or documents are linked to this record.
Start is estimated for Dec 2026; primary completion for Mar 2027, 3 months later.
Of 150 non-industry interventional studies with no phase under Hypersensitivity, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 43. This study's planned 3 months is below that.
Counting every sponsor, half of 174 studies reached it within 20 months; a quarter within 5 and three quarters within 41.
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Fu Jen Catholic University Hospital