Evaluating Collection Time of Intragastric Fluid During Endoscopy for Point-of-care Test-based <i>Helicobacter pylori</i> Polymerase Chain Reaction

Objective To evaluate the influence of sample collection time during esophagogastroduodenoscopy (EGD) on the accuracy of a newly approved point-of-care test (POCT)-based polymerase chain reaction kit for detecting Helicobacter pylori and clarithromycin susceptibility in gastric wash fluid. Methods Intragastric fluid was collected at three time points: Collection Time 1 (start of EGD), Collection Time 2 (during EGD), and Collection Time 3 (after indigo carmine spraying). POCT-based quantitative polymerase chain reaction (qPCR) targeting 23S rRNA domain V (2142/2143) was used to quantify H. pylori DNA in the collected fluid at all three time points and compared with qPCR targeting 16S rRNA. Patients Fifty patients with suspected H. pylori infection were consecutively enrolled in this study over a three-month period and underwent EGD. Results In 9 out of 50 EGD cases that were H. pylori-positive, no significant differences in H. pylori DNA content, quantified using POCT-based qPCR targeting 23S rRNA, were observed between the three collection times: 1 vs. 2, p=0.81; 2 vs. 3, p=0.59; 1 vs. 3. Collection Time 2 had the strongest inverse correlation with the urea breath test (r=-0.80, p=0.01) and was the only time-point at which POCT-based qPCR could detect H. pylori in case 15. Conclusion This study suggests that the optimal collection timing for the H. pylori detection POCT kit (within 60 min) using intragastric fluid (with no biopsy) may be during EGD (Collection Time 2). However, our study had a limited sample size, so the findings must be verified through large-scale, multicenter collaboration studies.