Clinical Relevance of Staphylococcus aureus Nasal Colonization and Staphylococcal Enterotoxin-Specific IgE Sensitization in Late-Onset Asthma

This prospective observational study examined whether Staphylococcus aureus (SA) nasal colonization and staphylococcal enterotoxin (SE)-specific IgE sensitization synergistically affect clinical outcomes of adults with late-onset asthma (onset age >= 40 years). Nasal swabs were taken to evaluate SA colonization. Serum SE-IgE level was measured. Subjects were classified into 4 groups according to SA colonization and SE-IgE sensitization positivity. Among 181 patients with late-onset asthma recruited, the proportions of SA/SE (-/-), SA/SE (+ /-), SA/SE (-/ +), and SA/SE (+ / +) were 33.7%, 15.5%, 28.2%, and 22.6%, respectively. Severe asthma was more frequent in the SA/SE (+ / +) group than in the SA/SE (-/-) group (41.5% vs. 13.1%). The relationship of SA/SE (+ / +) with severe asthma was significant in multivariate logistic regression (vs. SA/SE (-/-); adjusted odds ratio: 4.36; 95% confidence intervals: 1.50-12.73; p = 0.007), whereas SA/SE (+ /-) or SA/SE (-/ +) was not. In conclusion, SA nasal colonization and SE-IgE sensitization may synergistically affect disease severity in late-onset asthmatics.