High prevalence of clarithromycin resistance and effect on Helicobacter pylori eradication in a population from Santiago, Chile: cohort study and meta-analysis

Abstract

Helicobacter pylori (H. pylori) eradication using standard triple therapy (STT) with proton pump inhibitors (PPI), amoxicillin and clarithromycin (CLA) has been the standard in Latin America. However, CLA resistance is a rising problem affecting eradication rates. Genetic polymorphisms of CYP2C19, a PPI metabolizer may also affect eradication. The primary aims of this study were to evaluate the effect of clarithromycin resistance on H. pylori eradication in a population from Santiago, and to establish the pooled clarithromycin resistance in Santiago, Chile. Symptomatic adult patients attending a tertiary hospital in Santiago were recruited for this study. CLA resistance and the polymorphisms of CYP2C19 were determined on DNA extracted from gastric biopsies, using PCR. The STT was indicated for 14 days and eradication was determined by a urea breath test 4–6 weeks after therapy. A meta-analysis of CLA resistance studies among adult residents in Santiago was performed. Seventy-three out of 121 consecutive patients had positive rapid urease test (RUT) and received STT. Sixty-nine patients (95%) completed the study. The H. pylori eradication rate was 63% and the prevalence of CLA resistance was 26%. According to the CYP2C19 polymorphisms, 79.5% of the RUT-positive patients were extensive metabolizers. Multivariable analyses showed that only CLA resistance was significantly and inversely associated with failure of eradication (OR: 0.13; 95% confidence interval [95% CI], 0.04–0.49). A meta-analysis of two previous studies and our sample set (combined n = 194) yielded to a pooled prevalence of CLA resistance of 31.3% (95% CI 23.9–38.7). Our study shows that CLA resistance is associated with failure of H. pylori eradication. Given the high pooled prevalence of CLA resistance, consideration of CLA free therapies in Santiago is warranted. We could recommend bismuth quadruple therapy or high-dose dual therapy, according to bismuth availability. Further studies need to evaluate the best therapy.

Clinical factors associated with initial Helicobacter pylori eradication therapy: a retrospective study in China

“…Several studies have shown the eradication rates to be 75% 5 , 8 . Resistances to antibiotics, particularly clarithromycin, is the crucial factor affecting H. pylori eradication therapy 9 , 10 . The clarithromycin resistance rate has been found to be up to 50% in China 11 .…”

Review – Treatment of Helicobacter pylori infection 2020

“…An unprecedented number of studies last year reported on the important topic of antimicrobial resistance of H pylori strains 24‐60 . These are outlined in Table 1.…”

Régimen basado en Vonoprazan es más efectivo que el basado en inhibidores de la bomba de protones como primera línea en la erradicación de Helicobacter pylori Estudio clínico randomizado

“…La tasa de infección varía según zona geográfica. Se estima que un 50% de la población mundial es portadora y en Chile más del 70% de los adultos estarían contagiados 11,12 . Existe una tendencia a la disminución en la prevalencia de H. pylori a nivel mundial, especialmente en países desarrollados y en niños 13 .…”

“…De hecho, los consensos de América Latina, Toronto y Maastricht V recomiendan no usar la triterapia en zonas donde la resistencia a claritromicina sea mayor de 15% 5,16,19 . Estudios recientes demuestran que en Chile la resistencia a dicho antibiótico ha aumentado por sobre el 20% 12 . Frente a este problema, se ha generado una búsqueda de diferentes alternativas terapéuticas, libres de claritromicina, como la cuatriterapia con bismuto, adicionar metronidazol, o uso de altas dosis de amoxicilina 20 .…”