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

Introduction: 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 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 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 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 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 infection and children's persistent asthma in Greece.