Interleukin-1β and Interleukin-1 receptor antagonist gene polymorphism in pediatric patients with Helicobacter pylori-associated chronic gastritis

Background: The severity of Helicobacter pylori infection is determined by the interplay between bacterial virulence, host genetic and environmental factors. This study aimed to identify interleukin-1 beta (IL-1β) and interleukin receptor antagonist (IL-1RN) gene polymorphisms and their associations with H. pylori infection, and severity of chronic gastritis in Egyptian children.

Methods: A case control study was conducted on 100 children (50 H. pylori positive and 50 controls). Genotyping of IL-1β-31 gene was done by PCR-CTPP (confronting two-pair primers), of IL-1β-511 was performed using allele specific PCR, and investigation of the variable number tandem repeat polymorphism of the IL-1RN gene was done by PCR.

Results: The genotype C/T of IL1β-511 was the predominant genotype (36/50; 72%) among H. pylori positive cases (p ≤ 0.001). The presence of C/T genotype at position 511 of IL1β was associated with increased risk of infection with H. pylori (p ≤ 0.001, odds ratio = 6.612) and with more severe disease (p = 0.004, odds ratio = 8.333). No association of IL-1β-31 or IL-1RN gene polymorphisms with H. pylori infection or with risk of severe gastric diseases was found. Children who carry two polymorphisms are almost four times at risk for development of H. pylori infection (p = 0.026, odds ratio = 3.937).

Conclusions: Polymorphism at position -511 of IL1β gene is associated with increased risk of H. pylori infection as well as of severe corpus gastric disease in Egyptian children. This population should be considered a high-risk group, which needs regular gastric endoscopic surveillance, and should be target for H. pylori eradication. Lay summaryThe genotype C/T of IL1β-511 gene was the predominant genotype (36/50; 72%) among H. pylori positive children. Polymorphism at position -511 of IL1β gene is associated with increased risk of Helicobacter pylori infection as well as of severe corpus gastric disease in Egyptian children. No association of IL-1β-31 or IL-1RN gene polymorphisms with H. pylori infection or with risk of severe gastric diseases in Egyptian children.