Gastric juice‐based PCR assay: An alternative testing method to aid in the management of previously treated Helicobacter pylori infection

Abstract

Background Culture of Helicobacter pylori with previous eradication failure has been emphasized in clinical guidelines. The current unmet need to manage previously treated H pylori is one tool with diagnostic accuracy and ability for antibiotics susceptibility. Gastric juice PCR can provide diagnosis and antibiotics susceptibility; however, whether treatment failure affects its accuracy remains uninvestigated. Our study aimed to investigate diagnostic accuracy and antibiotics susceptibility of juice PCR in previously treated H pylori and to compare with the current standard of culture. Methods We categorized all 547 patients into treatment‐naïve, post‐1st treatment, post‐2nd treatment, and post‐3rd treatment. Helicobacter pylori infection was confirmed using gold standards. Sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic (ROC) curve and area under ROC curve (AUC) of juice PCR and culture were calculated. Intra‐gastric H pylori density was evaluated. Lastly, the antibiotics susceptibility results of gastric juice and culture were compared. Results Our findings demonstrated AUC was higher in juice PCR than culture in all patients (96.7% vs 91.3%, P < 0.0001). The superiority of juice PCR was statistically significant in previously treated patients (P < 0.0001) but not in treatment‐naïve patients (P = 0.13). Antral H pylori density was less marked in previously treated patients (P = 0.014). The comparisons of PCR‐RFLP and E‐test for Clarithromycin resistance showed reliable AUC = 89.8%. Conclusion Compared with the current standard of culture, the gastric juice PCR contains the strengths of performing the antibiotics susceptibility and overcomes the shortcomings of low accuracy. Consequently, gastric juice PCR suits the unmet need to manage previously treated H pylori.

Review: Diagnosis of Helicobacter pylori infection

“…In comparison with histology, the sensitivity of ddPCR to detect H. pylori infection was 93%. 32 Bachir et al determined primary resistance of H. pylori to clarithromycin, fluoroquinolone, and tetracycline in Algerian adult patients and found an excellent agreement between phenotypic and genotypic susceptibility testing methods. The limitations of this study are the lack of a reference method for clarithromycin resistance, the lack of samples of non-infected individuals to determine the specificity of the method for the detection of infection when using FFPE tissue, and the lack of information on previous eradication therapies.…”

“…In contrast, the sensitivity of gastric juice PCR, which also allowed clarithromycin susceptibility testing, was not affected by previous eradication attempts and was shown to be significantly higher than that of culture in treated patients. 32 Bachir et al determined primary resistance of H. pylori to clarithromycin, fluoroquinolone, and tetracycline in Algerian adult patients and found an excellent agreement between phenotypic and genotypic susceptibility testing methods. Thus, molecular detection of mutations associated with resistance proved to be an appropriate alternative to culture-based antimicrobial susceptibility testing in this population.…”

What Is New in Helicobacter pylori Diagnosis. An Overview

“…In addition to gastric biopsies, molecular tests can be applied to the gastric mucus present on biopsy forceps placed into water or into the RUT gel [ 88 ], and the dual-priming oligonucleotide-based multiplex PCR, performed on CLO ® -test kits, proved to be superior to RUT and histology, in patients with a bleeding peptic ulcer [ 89 ]. Alternatively, molecular tests to detect H. pylori and its susceptibility to antibiotics can be performed on gastric juice [ 90 , 91 , 92 ]. A droplet-digital PCR may also be applied to formalin-fixed, paraffin-embedded gastric tissue to determine the presence of clarithromycin resistance [ 93 ], or by next generation sequencing to determine levofloxacin and tetracycline resistance [ 94 ] ( Figure 2 ).…”

Application of molecular techniques inHelicobacter pyloridetection: limitations and improvements

“…19,47 Alternatively, a real-time diagnostic device, for example, EndoFaster performing quick endoscopic gastric juice analysis or gastric juice-based PCR assay, should be considered. 48,49 The accuracy of PCR-based methods is limited to the number of H. pylori genes (eg, vacA, cagA, ureA, glmM, 16S rRNA, and 23S rRNA) tested. It is believed that more than one gene should be included to minimize the chance of "identifying" some close-related species.…”

“…When used for invasive tests, molecular methods also have the limitation of mis‐sampling due to bacterial patchy distribution in the stomach, therefore, more than one antral biopsy specimen should be checked 19,47 . Alternatively, a real‐time diagnostic device, for example, EndoFaster performing quick endoscopic gastric juice analysis or gastric juice‐based PCR assay, should be considered 48,49 …”