Differences in interleukin 8 expression in Helicobacter pylori–infected gastric mucosa tissues from patients in Bhutan and the Dominican Republic

Abstract

The outcomes of Helicobacter pylori infection vary geographically. H. pylori strains, disease presentation, and environments differ markedly in Bhutan and Dominican Republic. The aims were to compare the strains, histology and expression of interleukin (IL)-8 and IL-10 from gastric mucosa from the two countries. H. pylori status was assessed by the combination of rapid urease test, culture and histology. Histology was evaluated using the updated Sydney System and cytokines in gastric biopsies were measured using real-time PCR. There were 138 subjects from Bhutan and 155 from Dominican Republic. The prevalence of H. pylori infection was 65% and 59%, respectively. The genotype of cagA was predominantly East-Asian type in Bhutan vs. Western type in Dominican Republic. Gastritis severity was significantly higher in H. pylori-infected subjects from Bhutan than those from Dominican Republic. IL-8 expression by H. pylori-infection was 5.5-fold increase in Bhutan vs. 3-fold in Dominican Republic (p <0.001); IL-10 expression was similar. IL-8 expression levels among H. pylori-infected cases tended to be positively correlated with polymorphonuclear leucocyte (PMN) and monocyte infiltration (MNC) scores in both countries. IL-8 expression among those with grade 2 and 3 PMN and MNC was significantly higher in Bhutan than in Dominican Republic. The difference in IL-8 expression in two countries is reflected in the different disease pattern between them. Whether the dominant factor is differences in H. pylori virulence, in host-H. pylori-environmental interactions, genetic factors or all remains unclear. However, severity of inflammation appears to be a critical factor in disease pathogenesis. We compared IL-8 mRNA levels between high gastric cancer risk country; Bhutan (mainly East Asian type H. pylori) and lower gastric cancer risk country; Dominican Republic (mainly Western type H. pylori).

Interleukin-17C in Human Helicobacter pylori Gastritis

“…Samples from 136 subjects from Bhutan (median age, 40 years; age range, 16 to 92 years) and 157 subjects from the Dominican Republic (median age, 47 years; age range, 17 to 91 years) were included in this study (Table 1). These subjects were previously reported in studies of the effect of H. pylori infection on IL-8 and IL-10 mRNA levels (22) and TLR10 expression (23) in the gastric mucosa.…”

“…It is thought that IL-8, a CXC chemokine specific for neutrophil granulocyte chemotaxis, plays a major role in the H. pylori-associated acute inflammatory response (24,25). We previously showed that gastric IL-8 mRNA levels were significantly higher in H. pylori-infected subjects from Bhutan (East Asian-type cagA) than from the Dominican Republic (in both Western-type cagA and cagA-negative infections) (22). The NF-B signaling pathway is thought to be involved in the induction IL-8 and IL-17C (26).…”

“…We used gastric biopsy specimens obtained from subjects with mild dyspeptic symptoms living in two widely separated regions, Bhutan, in South Asia, and the Dominican Republic, a Caribbean country (22,23). Written informed consent was obtained from all participants, and the protocols were approved by the ethics committee of Oita University Faculty of Medicine (Japan), Chulalongkorn University (Thailand), and Universidad Autonoma de Santo Domingo (Dominican Republic), as well by the local hospitals where we collected gastric mucosal specimens.…”

“…We used an uninfected sample as a calibrator. The expression of IL-8 mRNA was also analyzed by qPCR as described previously (22). Gastric epithelial cell culture and H. pylori culture used for in vitro studies.…”

Interleukins 17 and 23 in patients with gastric neoplasms

“…We hypothesize that the discrepancy may be caused by multiple factors, including completely different ethnic origins of study populations. In previous studies, it has been demonstrated that the genetic expression of selected cytokines, their impact on gastric carcinoma risk, and their importance in the development/progression of this disease may vary among patients of different ethnic origin, and may also be influenced by the genetic profile of Helicobacter pylori strains present in different parts of the world3637. In terms of the Polish population, our previous study regarding the significance of interleukins in the pathogenesis of pancreatic neoplasms also revealed significantly lower IL-23 concentrations in patients with pancreatic cancer38.…”