10-Year Trends in Helicobacter pylori Eradication Rates by Sitafloxacin-Based Third-Line Rescue Therapy

Background/Aims: Sitafloxacin (STFX)-containing regimens were shown to be useful options for third-line Helicobacter pylori eradication therapy. It is reported that resistance to quinolone is also increasing globally. Therefore, we conducted an analysis of the current efficacy of a 10-day-STFX-containing third-line rescue therapy and the changes of antibiotic resistance to H. pylori compared to 2 historical controls. Methods: Patients in whom eradication treatment using both first-and second-line triple therapies failed were enrolled from 2014 to 2015. The minimum inhibitory concentrations of STFX, clarithromycin (CLR), amoxicillin (AMX), metronidazole (MTZ) and the gyrA mutation status of the H. pylori strains were determined before treatment. After that, the patients received a 10-day triple therapy containing esomeprazole (20 mg, b.i.d.), AMX (500 mg, q.i.d.) and STFX (100 mg, b.i.d.; 10-day EAS). The eradication rate and the rate of antibiotic resistance to H. pylori were compared with 2 previous reports about STFX-containing third-line rescue therapies in 2009-2011 and 2012-2013. To explore the association between the eradication rates of regimens containing STFX, AMX and proton pump inhibitors and the location of gyrA mutation or AMX resistance, a meta-Analysis was attempted. Results: The overall eradication rates, the eradication rate for gyrA mutation negative-and positive-strains were 81.6% (31/38), 94.7% (18/19) and 68.4% (13/19) respectively. These rates were not significantly different from 2 previous reports. The resistant rates to STFX, CLR, AMX, MTZ and the rate of presence of mutation in gyrA were 50.0, 81.6, 36.8, 78.9 and 50.0%, respectively, which was also not significantly different from 2 previous reports. A meta-Analysis showed that the relative risk of the eradication failure is significantly lower in gyrA mutation negative strains compared to gyrA mutation positive strains, and that the relative risk of the eradication failure is significantly lower in gyrA mutation at D91 compared to gyrA mutation at N87 (p < 0.001 and p = 0.022, respectively). Moreover, a meta-Analysis showed that the relative risk of the eradication failure is significantly lower in AMX-sensitive strains compared to AMX-resistant ones. Conclusion: Changes in the rate of antibiotic resistance to H. pylori were not observed from 2009 to 2015. The status of gyrA mutation is a superior marker for predicting successful eradication in STFX/AMX-containing triple regimen as a third-line rescue therapy.