Endoscopic urease sensor system for detecting Helicobacter pylori on gastric mucosa

Background: It is now accepted that the curing of Helicobacter pylori infec tion will result in healing of chronic active gastritis and will change the natural history of gastroduodenal ulcer disease. Both endoscopic observati on and evaluation of H. pylori status of the stomach are necessary for diag nosis and treatment of such patients. We carried out a clinical evaluation of an endoscopic tube type urease sensor system for the detection of H. pyl ori an the gastric mucosa. The differential output of two pH-sensitive fiel d effect transistors at the tip of the endoscopic tube reflects the pH chan ge in a urea solution depending on the existence of urease. Methods: In vitro experiments and clinical evaluation of the system were pe rformed. Fifty-one patients who were suspected to have a gastroduodenal dis order were examined for H, pylori infection with this system, using the com bination of histologic and bacteriologic examinations and rapid urease test as the references. Results: Clinical sensitivity and specificity of this system were 26 of 28 (92.9%) and 22 of 23 (95.7%), respectively. A measurement at 1 site is comp leted in about 1 minute. Repetition of the procedure provides multi-site me asurements. Conclusions: The present system makes possible quick on-site detection of H . pylori under endoscopic observation, with satisfactory sensitivity and sp ecificity.