Published online Jun 7, 2014. doi: 10.3748/wjg.v20.i21.6547
Revised: December 13, 2013
Accepted: January 8, 2014
Published online: June 7, 2014
Processing time: 323 Days and 3.3 Hours
AIM: To investigate whether tissue samples processed by the rapid urease test (RUT) kit are suitable for dual-priming oligonucleotide-based multiplex polymerase chain reaction (DPO-PCR) to detect Helicobacter pylori (H. pylori).
METHODS: A total of 54 patients with specific gastrointestinal symptom were enrolled in this study. During endoscopy, gastric biopsy specimens were taken for histology, RUT, and DPO-PCR. DPO-PCR was performed on gastric biopsy samples and tissue samples that were analyzed by RUT at 2 separate institutes. In detecting H. pylori, the concordance rate of the DPO-PCR tests between the tissue samples that had been submitted to RUT and the gastric biopsy samples was investigated.
RESULTS: H. pylori co-occurred with 76.0% (19/25) of gastric ulcers, 64.3% (9/14) of duodenal ulcers, and 33.3% (4/12) of gastritis cases. H. pylori infection was found in 100% (3/3) of the patients with both gastric and duodenal ulcers. Overall, H. pylori was detected in 35 of 54 (64.8%) patients. The diagnostic sensitivities of histology, RUT, and DPO-PCR were 85.7% (30/35), 74.3% (26/35), and 97.1% (34/35), respectively (P = 0.02). The positive predictive value (PPV) of DPO-PCR was 94.4%, whereas the negative predictive value (NPV) was 94.7%. In the rapid urease test (CLOtest)-negative cases, the frequency of positive DPO-PCR and histologic results was 20.0% (7/35). The concordance rate of the DPO-PCR tests between the tissue samples from the RUT kit and the gastric biopsy samples was 94.4% (51/54). The rate of DPO-PCR and silver stain positivity in the RUT-negative cases was 20.0% (7/35).
CONCLUSION: In diagnosing H. pylori infection, DPO-PCR can be performed on tissue samples that have been processed by the RUT kit. Particularly, in patients with RUT-negative results, DPO-PCR on these tissue samples could be helpful in detecting of H. pylori infection.
Core tip: The rapid urease test (CLOtest) alone is unreliable in diagnosing Helicobacter pylori (H. pylori) infection and does not provide information about resistance to clarithromycin. Therefore, we investigated whether tissue samples that have been analyzed by the CLOtest kit are suitable for dual-priming oligonucleotide-based multiplex PCR (DPO-PCR) to detect H. pylori. Our results demonstrated that the DPO-based multiplex PCR test using tissue samples processed by the CLO kit is appropriate for detecting H. pylori and clarithromycin resistance. Particularly, in patients with CLO-negative results, this method is helpful for diagnosing H. pylori infection. Moreover, it would be beneficial in economical aspects.