Associations of Helicobacter pylori seropositivity and gastric inflammation with pediatric asthma

Objective: Controversy exists regarding an association between Helicobacter pylori infection and asthma in children. We examined the hypotheses of inverse associations of H. pylori seroprevalence and pepsinogen (PG) levels, as markers of gastric inflammation, with asthma in children. Methods: A hospital-based case-control study was conducted among children aged 4.8 to 17.3 years in Israel. Confirmed asthma cases (n = 75) were recruited through a pulmonary clinic, and controls (n = 160) without asthma were enrolled. Using enzyme-linked immunosorbent assays we measured the presence of H. pylori immunoglobulin G (IgG) antibodies, IgG antibodies to cytotoxin-associated gene A antigen (CagA) (virulent factor), serum PG levels and exposure to other enteric pathogens (Shigella flexneri). Multivariable logistic regression models were applied. Results: H. pylori IgG seropositivity was 25% and 40% among cases and controls, respectively (P =.03). H. pylori CagA IgG seropositivity was associated with reduced risk of asthma (adjusted odds ratio [OR], 0.33 [95% CI, 0.11-0.95] but not for the CagA negative serology (adjusted OR, 0.70 [95% CI, 0.32-1.54]). Children who were H. pylori seropositive with a PGI:PGII of ≤6.78 (severe gastric inflammation) had a lower likelihood of asthma (adjusted OR, 0.31 [95% CI, 0.10-0.89]) than did seronegative children. Exposure to Shigella flexneri did not differ between cases and controls, nor according to H. pylori seropositivity. Among the asthmatic children, pulmonary function did not differ according to H. pylori seropositivity. Conclusions: H. pylori infection and its related gastric inflammation may have a protective role in the risk of pediatric asthma and further research into a potential causal pathway is required.