Iron Deficiency and IL1β Polymorphisms in Helicobacter pylori-infected Children.

Background: Helicobacter pylori infection has been associated with an imbalance of iron homeostasis. IL-1β 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-1β cluster and gastric IL1β 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 iron-binding capacity. Polymorphisms in the IL-1β cluster (positions -511, -31, +3954, ILRN) were determined by PCR-RFLP. Gastric mucosal expression of IL-1β 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 IL1β gene cluster polymorphisms between infected and uninfected children. Helicobacter pylori-infected children with ID had significantly increased gastric IL1β mRNA in comparison with infected children without ID. In addition, a significant positive correlation was observed between mucosal IL-1β 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-1β.