It is well known that bleeding decreases the sensitivity of H. pylori diagnostic tests in patients with peptic ulcer bleeding,

but Choi et al. [29] determined that histology is quite a reliable test, regardless of the presence of bleeding. Furthermore, a meta-analysis by Tian et al. [30] showed that histology had a higher sensitivity and specificity than the UBT and the RUT for the diagnosis of H. pylori infection after a partial gastrectomy. Peptide nucleic acid-FISH is a genotypic method for detecting the clarithromycin resistance of H. pylori, based on fluorescent in situ hybridization [31]. The set of probes targeting the point mutations responsible for clarithromycin resistance was applied to H. pylori ABT-888 suspensions, and it showed 100% sensitivity and specificity (95% CI, 79.9–100 and 95% CI, 71.6–100, respectively) [31].

The RUT has an accuracy of >90% in the detection of H. pylori infection, and a positive RUT is learn more sufficient to initiate eradication treatment [19]. RUT is relatively inexpensive, and it provides rapid results. In the case of an active ulcer bleeding, the sensitivity of RUT may be reduced [29]. Koumi et al. [32], in a prospective study, proved that a faster urease test (H. pylori Quick test; Biohit, Helsinki, Finland) is more cost-effective than the CLO test. Furthermore, Li et al. [33] showed that gastric biopsy specimens stored in the RUT gel for 30 days can still be used to confirm the diagnosis of an H. pylori infection and test for clarithromycin susceptibility. According to the Maastricht IV Consensus

Report, H. pylori culture and antibiotic susceptibility testing should be performed if primary resistance to clarithromycin exceeds 20% in a given geographical area [19]. Furthermore, after the first eradication failure, culture should be considered in all regions before providing second-line treatment [19]. Some factors like peptic ulcer bleeding may affect the tests for H. pylori detection. Culture and three other tests (RUT, histology, and anti-CagA IgG) were performed under such circumstances [34]. The sensitivity MCE of the biopsy specimen’s culture, histology, and RUT was 86.4, 68.2, and 65.9%, respectively, and the specificity was 100, 75, and 77.8%, respectively, indicating that culture was the best method for the detection of H. pylori in bleeding patients with peptic ulcer bleeding after nonsteroidal anti-inflammatory drug consumption. Contrary to these findings, other authors concluded that bleeding decreased the sensitivity of H. pylori tests in patients with peptic ulcer, especially RUT and culture, while histology was found to be the most reliable test regardless of the presence of bleeding [29]. As the decreased density of H. pylori in atrophic gastritis may lead to a low sensitivity of the tests, Sudraba et al.