Biofilms correlate with T_H1 inflammation in the sinonasal tissue of patients with chronic rhinosinusitis

Objective: Determine the prevalence of bacterial biofilms in surgical chronic rhinosinusitis (CRS) patients and characterize the inflammatory response associated with biofilm CRS. Study Design: Cross-sectional. Setting: Tertiary care academic center. Subjects and Methods: Sinonasal mucosa and peripheral blood were collected from 60 CRS patients. Mucosal biofilms were demonstrated by scanning electron microscopy. Leukocyte subpopulations were determined by flow cytometry. Cytokines were identified with a luminex-based assay on the lysate of homogenized tissue or plasma. Results: Of the 60 samples, 17 were determined to be positive for the presence of biofilms. Oral steroid-naive CRS patients with biofilm demonstrated a local T_H1 inflammatory response with significantly elevated levels of interferon-γ (INF-γ), granulocyte colony-stimulating factor, macrophage inflammatory protein-1 β, and neutrophils in the sinonasal mucosa. No differences were present at the systemic level. Conclusion: Sinonasal bacterial biofilms correlate to a T_H1 skewed local but not systemic inflammatory response in CRS. This difference is abrogated by the use of oral steroids.