Risk of Helicobacter pylori infection and childhood asthma in Iran: A review and meta

Asthma is one of the most common chronic respiratory diseases worldwide that especially affects children. Scientific data suggesting that infectious agents, such as Helicobacter pylori infection, can influence the development of allergic reactions. Therefore, we aimed to investigate the risk of H. pylori infection in childhood asthma. Systematic literature searching was done to retrieved articles distributed by Iranian authors in the Web of Science, PubMed, Embase, and Scopus from the beginning of databases to Jun 2019. Four studies that met our inclusion criteria were included for data collection and meta-analysis. The inclusion criteria were articles that performed among the Iranian population, the method to confirm H. pylori infection has been declared, and the prevalence of H. pylori in both asthmatic and control groups were mentioned. The studies in the asthmatic group involved 288 participants, of which the overall occurrence of H. pylori infection was calculated at 16.6% (95% CI: 12.7-21.4). While healthy control group involved 616 cases that the overall occurrence of H. pylori infection among them was estimated at 20.9% (95% CI: 11.9-34.0). The estimate of outcome showed that the risk of H. pylori infection was 0.75-fold (95% CI: 0.47-1.18; P = 0.21) lower in asthmatic patients than in the healthy controls, but statistically was not significant. As a first country-based study, the results did not support the association between H. pylori infection and the risk of childhood asthma. However, further prospective longitudinal studies with a uniform diagnostic method of H. pylori are recommended.