Impact of mucosal biofilm and bony osteitis on chronic rhinosinusitis with nasal polyps

Background Chronic rhinosinusitis (CRS) is a common inflammatory disorder whose underlying etiopathogenesis has not yet been completely understood and appears to be multifactorial. Microbial biofilms and bony osteitis are gaining an increased concern as they are considered to be among the possible factors that contribute to the overall local inflammatory load in chronic rhinosinusitis (CRS). This study investigated the impact of mucosal biofilm and bony osteitis on the pathophysiology and severity of chronic rhinosinusitis with nasal polyps (CRSwNP). Results Forty-five CRSwNP patients performing functional endoscopic sinus surgery (FESS) and 10 control patients were involved in this cross-sectional study. Mucosal and bony specimens from ethmoid sinus were obtained for both light and scanning electron (SEM) microscopic examination. The histopathologic bony grade was positive in 40/45 of CRSwNP patients versus 6/10 of the control patients ( P = 0.300); histopathologic mucosal grade was 44/45 versus 4/10 ( P < 0.001), and tissue eosinophilia was 45/45 versus 6/10 ( P < 0.001); biofilm was positive in 37/45 versus 4/10 ( P = 0.012). The mean of the sinonasal outcome treatment score (SNOT)-22 is 39.8 versus 50.5 ( P = 0.067); Lund-Mackay score (LMS) is 19.6 versus 3.1 ( P < 0.0001). Conclusion (1) Mucosal biofilms and osteitis were detected in patients undergoing FESS for CRSwNP and also in controls without CRS. This suggests that mucosal biofilms and osteitis may not alone be the etiology of CRS without other cofactors. The pathogenesis of biofilms could be related to host factors. (2) The high odds ratio and wide confidence interval in our study suggest that there is a statistically significant association between biofilm formation and CRSwNP. (3) The high grade of mucosal inflammation and tissue eosinophilia suggests the inflammatory load added by osteitis and bacterial biofilm (BBF).