Helicobacter pylori strains and histologically‐related lesions affect the outcome of triple eradication therapy: a study from southern Italy

Summary Background : Certain evidence suggests that Helicobacter pylori strains expressing genes for cytotoxin production show a higher sensitivity than non‐cytotoxic organisms to eradication treatment. No data are available on the involvement of bacterium‐related lesions in different therapeutic outcomes. Aims : (i) To investigate whether differences in eradication rates may be related to the different expression of virulent strains (cagA, vacA, iceA) in patients undergoing proton pump inhibitor‐based triple therapy, and (ii) to evaluate whether therapeutic outcome may be affected by bacterium‐induced gastric lesions. Methods : One hundred and ten H. pylori‐positive subjects were enrolled. H. pylori was genotyped by polymerase chain reaction. Treatment consisted of lansoprazole–amoxicillin–clarithromycin, twice daily for 1 week. Eradication was checked by urea breath test. Results : The eradication rate was 70%, and the absence of cagA was associated with unsuccessful treatment. No difference between the groups with successful and unsuccessful eradication was found with regard to vacA and iceA. Lympho‐epithelial lesions and fibrosis were associated with unsuccessful treatment. Conclusions : The present data confirm the importance of cagA (but not vacA and iceA) as a predictor of successful eradication. When fibrosis and lympho‐epithelial lesions are present, therapy appears to be less effective. Therefore, these histological features may be involved in an unsuccessful therapeutic outcome.