Dual-priming oligonucleotide-based multiplex PCR using tissue samples in rapid urease test in the detection of Helicobacter pylori infection.

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.