A rapid, low‐dose, ¹³C‐urea tablet for the detection of Helicobacter pylori infection before and after treatment

Abstract

SUMMARYBackground: A new urea breath test (UBT) has been described which uses a tablet formulation of 13 C-urea with citric acid and allows breath sampling to be performed as early as 10 min after ingestion of the tablet. Aim: To assess the diagnostic accuracy of tablet-based 13 C-UBTs (50 and 100 mg 13 C-urea) before and after Helicobacter pylori eradication treatment, compared with an endoscopy gold standard and a conventional 13 C-UBT (75 mg 13 C-urea).Methods: Two hundred dyspeptic patients underwent endoscopy, followed by tablet-based 13 C-UBTs (50 and 100 mg 13 C-urea) and a conventional 13 C-UBT (75 mg 13 C-urea). H. pylori-infected patients were prescribed treatment and asked to return 4-6 weeks after the end of therapy for repeat endoscopy and 13 C-UBTs.Results: One hundred and thirteen patients were infected with H. pylori. The sensitivity and specificity of the conventional 13 C-UBT were both 100%; the sensitivity and specificity of the 100-mg tablet-based 13 C-UBT were 100% and 98.85%, respectively. For the 50-mg tablet-based 13 C-UBT, cut-off values of the difference over baseline of between 1.65 and 3.15 provided a sensitivity and specificity of 100%. At follow-up, the sensitivity and specificity of the conventional and 100-mg tablet-based 13 C-UBTs were both 100%. For the 50-mg tablet-based 13 C-UBT, cutoff values of the difference over baseline of between 1.49 and 1.56 gave a sensitivity and specificity of 100%. Conclusions: New 10-min 13 C-UBTs using tablet formulations of 13 C-urea with citric acid are reliable for the assessment of H. pylori status pre-and posttreatment.

Use of a Novel Enzyme Immunoassay Based on Detection of Circulating Antigen in Serum for Diagnosis ofHelicobacter pyloriInfection

“…Although PCR, a powerful method known for its high sensitivity, can detect low numbers of H. pylori and has been used to follow up eradication therapy, PCR requires specialized laboratory facilities and is not generally available as a routine diagnostic test (13). The urea breath test has been the most widely used accurate noninvasive test, both in the pretreatment examination of infected individuals and for early-posttreatment follow-up, and meets the requirements for such a test (9). However, the performance of the test has been associated with some disadvantages.…”

Low Dose Capsule Based 13c-Urea Breath Test Compared With the Conventional 13c-Urea Breath Test and Invasive Tests

“…There is no interference of the oral flora, as the capsule is swallowed and disintegrated directly in the stomach. Capsules prevented the urea to be released before reaching the stomach, requiring a lower dose of 13 C-urea (7,13,25,27) . In this report, we showed that 13 C-urea breath test performed with formulated 50 mg hard gelatin capsule with citric acid and taken with orange juice (pH = 3.0) had almost perfect agreement (Kappa Index measure of agreement = 1; P<0.05) with the conventional 13 C-urea breath test in powder dissolved in orange juice.…”

“…In Brazil, the conventional test with 13 C-urea in powder dissolved in orange juice has been widely performed in children with doses of 50 mg and 75 mg in patients with less than 30 kg and more than 30 kg, respectively (3,15,16,29) , and in adults (30) . However, the conventional test with liquid 13 C-urea in orange juice may suffer the influence of urease-producing oral flora, increasing 13 CO 2 excre-tion in earlier sample collections with false-positive results, also a higher dose is necessary (7,25,27) . Capsule based 13 C-urea breath test has been reported with lower dose than the conventional test with high sensitivity and specificity, avoiding bacterial oral flora interference, and in a shorter time (7,25,27,28) .…”

“…However, the conventional test with liquid 13 C-urea in orange juice may suffer the influence of urease-producing oral flora, increasing 13 CO 2 excre-tion in earlier sample collections with false-positive results, also a higher dose is necessary (7,25,27) . Capsule based 13 C-urea breath test has been reported with lower dose than the conventional test with high sensitivity and specificity, avoiding bacterial oral flora interference, and in a shorter time (7,25,27,28) . One of the limitations for 13 C-urea breath test to be incorporated into daily gastroenterology practice in Brazil is the substrate ( 13 C-urea) acquisition in capsule presentation (6) .…”

Effect of different organic acids (citric, malic and ascorbic) on intragastric urease activity

“…Citric acid test meals have been shown to result in a greater degree of urea hydrolysis than traditional nutrient-containing test meals. [1][2][3][4][5][6][7] The mechanism through which citric acid enhances urea hydrolysis is unclear. Citric acid will both acidify gastric contents and also retard gastric emptying.…”