The Diagnostic Validity of the Urea Breath Test
Condition: Helicobacter Pylori Infection
MeSH terms: Infections; Helicobacter Infections
Study type: Interventional

Summary: 
      1. To compare the diagnostic accuracy of the 13C-Urea breath test between using the citric
           acid as test meal and controlled group by endoscopic biopsy methods(histology, CLOtest
           and H. pylori culture).

        2. To compare the delta value of 13CO2 results between before and after ingestion of citric
           acid as test meal.
    

Detailed description: 
      1-1 Screening (visit 1, From -6 to -8 weeks) and H. pylori eradication

        1. To accept the agreement, confirm inclusion/exclusion criteria, and evaluate the baseline
           characteristics of patients

        2. H. pylori eradication

             -  First eradication: PPI-based triple therapy (standard dose of PPI b.i.d.,
                clarithromycin 500 mg b.i.d., and amoxicillin 1 g b.i.d. for 1 week), and
                sequential therapy (initial 5-day therapy with a combination of PPI b.i.d and
                amoxicillin 1g b.i.d, followed by 5 days of PPI b.i.d., clarithromycin 500mg
                b.i.d., and metronidazole 500mg t.i.d)

             -  Rescue therapy: bismuth-containing quadruple therapy [PPI b.i.d., tripotassium
                dicitrate bismuthate 300 mg q.i.d. (three tablets at 30 min before meals and one
                tablet at 2 hours after dinner), metronidazole 500 mg t.i.d., and tetracycline 500
                mg q.i.d.] for 1-2 weeks, or moxifloxacin-containing triple therapy (moxifloxacin
                400 mg q.d., amoxicillin 1g b.i.d., and PPI b.i.d.) for 1-2 weeks.

      1-2 Baseline (visit 2, 0 week): urea breath test

        1. Reconfirm inclusion and exclusion criteria

        2. Randomization for UBT test (citric acid group vs control group)

        3. In citric acid group: taking 4 g of citric acid solving in 200 ml of water 10 minutes
           before UBT.

        4. Perform UBT in both group

      1-3) Endoscopic surveillance (visit 3, 6 or later months)

        1. Endoscopic surveillance for final H. pylori status after UBT

             -  Histology, CLOtest or H. pylori culture

        2. Statical analysis for diagnostic accuracy of the UBT between citric acid group and
           controlled group: sensitivity, specificity, positive predictive value, negative
           predictive value, false positive rate, and false negative rate.

      2. Selecting 40 patients who showed UBT result between 2.5 to 4.0 in controlled group, the
      investigators are planning to reperform 13C-UBT after giving citric acid as test meal.

      And then, the investigators compare the change of UBT result before and after ingestion
      citric acid as test meal.
    

Intervention name(s): Citric acid
Intervention type(s): Drug
Intervention description(s): Giving the citric acid (4g) solving in 200 ml of water before UBT
Intervention MeSH terms: Citric Acid; Sodium Citrate
Allocation: Randomized
Intervention model: Parallel Assignment
Primary purpose: Diagnostic
Keywords: Helicobacter pylori infection; Eradication; Urea breath test