Staphylococci and staphylococcal superantigens in asthma and rhinitis: a systematic review and meta-analysis

There is a need for new treatment options of allergic respiratory diseases based on a better knowledge of their pathogenesis. An association between bacterial products and allergic airway diseases has been suggested by the results of human and animal studies that describe a link between Staphylococcus aureus enterotoxins and atopic diseases. The aim of the systematic review is to assess the evidence for a role of Staphylococcus aureus enterotoxins, as an environmental risk factor, for the development and/or the severity of asthma and allergic rhinitis.

We performed a systematic review of controlled clinical studies in adults and/or children affected by asthma/early wheeze and/or allergic rhinitis. To be eligible, studies had to use reproducible methods to provide evidence of exposure to S. aureus, clinical outcome and disease severity.

Ten studies, published between 2000 and 2007, fulfilled all eligibility criteria. Patients with asthma or allergic rhinitis showed an increased prevalence of positivity for measures of exposure to S. aureus in nine studies: differences were statistically significant (P < 0.05) in seven studies. In a meta-analysis of study results, patients with asthma were more likely than controls to have serum-specific IgE to Staphylococcus aureus enterotoxins (OR = 3.3, 95% CI: 1.6-7.1, P = 0.002); similarly, patients with allergic rhinitis were more likely than controls to test positive for local or systemic exposure to Staphylococcus aureus and/or or its enterotoxins (OR = 2.4, 95% CI: 1.3-4.7, P = 0.008).

A potential role of S. aureus superantigens in allergic respiratory diseases is supported by results of this meta-analysis of clinical studies.