Staphylococcus aureus increases cytokine and matrix metalloproteinase expression in nasal mucosae of patients with chronic rhinosinusitis and nasal polyps.

BACKGROUND: Staphylococcus aureus is a common bacterial pathogen associated with chronic rhinosinusitis with/without nasal polyps (CRSw/sNP). We investigated the effect of S. aureus on the secretion of eotaxin, interleukin (IL)-5, IL-8, IL-13, matrix metalloproteinase (MMP) 2, MMP-9, and tissue inhibitor of MMP (TIMP) 1 in nasal mucosae from CRSwNP patients to assess the roles of these materials in NP pathogenesis.
METHODS: We infected organ cultures of NP and inferior turbinate (IT) mucosae taken from patients with CRSwNP with S. aureus ATCC 25923 for 24 hours and incubated the cultures for an additional 48 hours at 37°C. S. aureus infection and staphylococcal enterotoxins were confirmed by real-time polymerase chain reaction. Eotaxin, IL-5, IL-8, IL-13, MMP-2, MMP-9, and TIMP-1 protein levels were measured by ELISA.
RESULTS: S. aureus infection significantly increased the concentrations of eotaxin, IL-5, IL-8, and IL-13 in the IT and NP groups (p < 0.01 for all comparisons). S. aureus infection also significantly increased the concentrations of MMP-2, MMP-9, and TIMP-1 in both groups (p < 0.001 for all comparisons). After S. aureus infection, the relative increases in eotaxin (6.42 versus 3.56), IL-5 (15.29 versus 8.89), MMP-2 (1.95 versus 1.58), MMP-9 (2.34 versus 1.95), and TIMP-1 (1.45 versus 1.31) were greater in the NP group than in the IT group.
CONCLUSION: S. aureus infection enhances the secretion of cytokines, MMP-2, MMP-9, and TIMP-1 by both NPs and IT mucosae from patients with CRSwNP. S. aureus may play an important role in the pathogenesis of NP via tissue remodeling as well as eosinophilic inflammation.