Iron Deficiency and IL1b Polymorphisms in Helicobacter pylori-infected Children

Abstract

Helicobacter pylori infection has been associated with an imbalance of iron homeostasis. IL-1b has been related with iron absorption disturbances through a variety of mechanisms. The aim of this study was to evaluate the presence of polymorphic variants for IL-1b cluster and gastric IL1b mRNA expression in H. pylori-infected children and their relationship with hypochlorhydria and iron deficiency (ID). Patients and Methods: Prospective study of 123 symptomatic children. At endoscopy, antral biopsies were taken for urease test, pathology and culture and blood for analysis of ferritin, transferrin, serum iron, and total ironbinding capacity. Polymorphisms in the IL-1b cluster (positions 511, 31, +3954, ILRN) were determined by PCR-RFLP. Gastric mucosal expression of IL-1b mRNA was determined by RT-PCR. Results: After exclusions, of 105 patients, 33 (31.4%) were H. pylori positive. Nine (8.6%) children were classified as iron deficient (ID). Helicobacter pylori positivity was associated with ID (OR: 5.1; 95% CI: 1.2–21.9) (p = .04). No significant differences were found in allele frequency for IL1b gene cluster polymorphisms between infected and uninfected children. Helicobacter pylori-infected children with ID had significantly increased gastric IL1b mRNA in comparison with infected children without ID. In addition, a significant positive correlation was observed between mucosal IL-1b mRNA and fasting gastric juice pH. Gastric pH values were significantly increased in H. pylori-infected patients with ID compared to uninfected children. Conclusions: The established association between H. pylori infection and ID in children may be mediated by increased gastric mucosal IL-1b.