High Helicobacter pylori Bacterial Load and Low Cytokine Expression Levels Are Associated with Nodular Gastropathy.

Abstract

Nodular gastropathy (NG) is an inflammatory condition of the gastric mucosa characterized by the endoscopic detection of multiple millimeter protrusions. A strong association between NG and Helicobacter pylori and a possible role of NG as a risk factor for undifferentiated gastric cancer have been described. The aim of this study was to characterize the pathogenic and inflammatory profile of patients with NG. Adult patients referred for upper gastrointestinal endoscopy were prospectively enrolled in this study. H. pylori infection status was determined by rapid urease test. Biopsies were stained with hematoxylin-eosin. Sydney and OLGA scores were used to assess gastritis characteristics and gastric cancer risk. PCR analysis was performed to determine bacterial load and virulence factors CagA (and its EPIYA motifs) and VacA alleles. Finally, gastric mucosa cytokine gene expression (IL-8, IL-1β, and TNF-α) was determined by real-time RT-PCR. Forty-eight patients, mean age of 36years, were recruited. All NG patients were infected by H. pylori. OLGA score was similar in both groups (NG patients and non-NG patients). NG patients had higher bacterial load in the gastric corpus (p = 0.01) and significantly less pro-inflammatory cytokine levels than non-NG infected patients (p = 0.01). In our study, NG is not associated with preneoplastic lesions. An increase in bacterial load without a concomitant increase in mucosal inflammatory cytokine responses in H. pylori-infected subjects with NG may represent a general dampening of immune responses or an additional mechanism of H. pylori active immune evasion.