Inverse association between Helicobacter pylori infection and childhood asthma in Greece: a case-control study

Abstract

Introduction: Helicobacter pylori infection is a well-established etiological factor for a variety of diseases such as peptic ulcer and gastric cancer. On the other hand, there is ongoing research suggesting that H. pylori might have a beneficial effect through a pivotal influence in the immunological response especially in asthma. The aim of the current case-control study was to evaluate the prevalence of H. pylori infection in asthmatic children.

Methods: Twenty-seven children with exacerbation of persistent asthma, aged 8.6±4.5 years (18 males, 9 females) and 54 age-sex-matched non-asthmatic controls were enrolled. Clinical examination and laboratory investigations were performed. Detection of H. pylori antigen (HpSA) in stool samples was performed by a commercial kit (bioNexia® kit, BioMérieux). Serum specific IgG antibodies were detected by a rapid chromatographic immunoassay (DIAsourceImmunoAssays). Serum IgE concentration was determined by electrochemiluminescence (ECL) (Roche Elecsys) and IgE levels ≥ 90 IU/mL were considered significantly elevated.

Results: In 3 (11.1%) of the 27 asthmatic children H. pylori infection (based on both detection of HpSA and specific IgG-Abs) was established, whereas as many as 16 of the 54 (29.6%) non-asthmatic ones were found infected (odds ratio 0.1; 95%CI, 0.039-0.305, p=0.026).

Conclusions: Our findings reveal an inverse relationship between H. pylori infection and children's persistent asthma in Greece.

Keywords: Asthma; Helicobacter pylori; children; persistent.

Figure 1. Level of total IgE in study group

Figure 2. Hypothesis of possible immune mechanism related to Helicobacter pylori infection and asthma

Gastric colonization by H. pylori, through dendritic cells (DC) mediated T cell expression, affects the Th1/Th2 response. The rise of gastric mucosal T regulatory cells (T regs) in H. pylori infection subsequently can provoke increase in the levels of interleukin (IL)-10 release, that inhibits a Th2 response and the activation of Th17. Thus H. pylori infection is favoring a Th1 response and not a Th2, that is related with allergic manifestations and asthma.