Comparison of Encapsulated Versus Nonencapsulated 14C‐urea Breath Test for the Detection of Helicobacter pylori Infection: A Scintigraphy Study

Background and Aims 14C-urea breath test (14C-UBT) is considered as “gold standard” for detection of active gastric H. pylori infection. However, till date no comparative study using encapsulated and non-encapsulated 14C-UBT protocols has been conducted in same subjects in identical conditions. We monitored gastric fate of capsule containing 14C-urea with real time display and compared sensitivities of these protocols at different time points of breath collection. Methods Non-encapsulated 14C-UBT was performed using 74 kBq of 14C-urea in 100 dyspeptic patients by collecting breath samples at 10, 15 and 20 minutes. Thereafter, within 2 days a gelatin capsule containing 14C-urea along with 6.0 MBq of 99mTc-diethylene triamine penta-acetic acid was administered to each patient for real time display of capsule movement and its fate in gastrointestinal tract by gamma camera. Simultaneously, breath samples were collected for 14CO2 measurement during image acquisition. Results Employing non-encapsulated 14C-UBT, 74 out of 100 dyspeptic patients were found to be H. pylori positive. Discordant 14C-UBT results were obtained in 4/74 (5.4%) cases using these two protocols. By employing encapsulated and nonencapsulated 14C-UBT protocols, sensitivities of 14C-UBT were found to be 90.5 versus 98.6% at 10 and 91.8 versus 97.2% at 15 minutes respectively; while these were 94.6 versus 100, 90.7 versus 98.6 and 83.7 versus 93.2% considering any one, two or all three positive values respectively. Conclusions Incomplete/non-resolution of 14C-urea capsule in stomach during the phase of breath collections appears to decrease sensitivity of encapsulated 14C-UBT as compared to nonencapsulated protocol for detection of H. pylori infection.