Objective: Serological antibody test have been widely performed to detect the presence of H. pylori, but they have not been used to evaluate the status of H. pylori after eradication. In this study we evaluated the diagnostic accuracy of a new serological test kit (E-plate) after eradication.
Method: Eradication of H. pylori was performed in 100 patients by proton pump inhibitor (PPI)+amoxicillin (AMPC)+clarithromycin (CAM) or PPI+AMPC therapy. Evaluation of H. pylori was done by culture, histology and rapid urease test before, and 8 weeks after, the treatment. Serological tests were also performed before and after treatment using the E plate. Cure was defined as no evidence of H. pylori at 8 weeks after the treatment. Receiver operating characteristic (ROC) analysis was performed to determine the ideal cut-off value for percentage change in the serological test.
Result: Success was obtained in 73 patients, failure in 20 patients and there were 7 dropouts. Serological test value was significantly decreased after treatment (44.3 +/- 29.6 U/ ml) compared to before treatment (94.8 +/- 73.2 U/ml) in the successful cases. In contrast, those with no significant change after treatment (62.7 +/- 31.3 U/ml) compared to before treatment (72.9 +/- 47.7 U/ml) were considered as failure cases. ROC analysis revealed that cut-off values of a 20%, 30%, and 40% decrease on E plate result yielded a sensitivity of 95.5%, 92.4%, 71.2% and a specificity of 73.3%, 84.2%, 94.7%, respectively.
Conclusion: The new E plate serological test kit for H. pylori was useful for distinguishing success from failure 8 weeks after completion of eradication therapy for H. pylori.