Relationships between IL-17A and Macrophages or MUC5AC in Eosinophilic Chronic Rhinosinusitis and Proposed Pathological Significance

Abstract

Recently, some researchers have reported that macrophages and neutrophils were related to severe asthma. Mucus hypersecretion and persistent airway inflammation result from increased expression of mucin gene (MUC5AC). Eosinophilic chronic rhinosinusitis (ECRS) is considered as intractable rhinosinusitis. From the viewpoint of “one way one disease,” we examined whether ECRS is associated with infiltrating macrophages, neutrophils, their promotive factors, and MUC5AC. We examined 21 nasal polyps with CRS. Each specimen was fixed in 10% phosphate-buffered formalin, embedded in paraffin, processed routinely, and then prepared as semithin sections (3.5 μm). We immunohistochemically observed the macrophages by using CD68, neutrophils by using neutrophil elastase and the promotive factors, monocyte chemotactic protein (MCP) 1, IL-17A, and IL-8, in both ECRS and non-ECRS. The number of macrophages (CD68+ cells), IL-17A, and MUC5AC+ cells in ECRS were significantly greater than in non-ECRS. The mean number of MCP-1+ cells in ECRS was greater than that in non-ECRS, but not significantly. There was a significant correlation in all cases between IL-17A and macrophages or MUC5AC+ cells. Neither the numbers of neutrophils (positive cells for neutrophil elastase) nor the IL-8+ cells showed any significant differences between ECRS and non-ECRS. Our study suggested that infiltrating macrophages, IL-17A and MUC5AC, as well as eosinophils could have roles in the development of ECRS.

Does Eosinophilic Inflammation Affect the Outcome of Endoscopic Sinus Surgery in Chronic Rhinosinusitis in Koreans?

“…16 There was a study suggesting that infiltrating macrophages, IL-17A, and a mucin gene (MUC5AC), as well as eosinophils could have roles in the development of eosinophilic CRS. 17 However, in the actual clinical setting of the authors, eosinophilic inflammation was less likely to be correlated with surgical outcomes. There were reports showing differences of the cellular composition of NP between the Koreans and Westerners.…”

Chronic Eosinophilic Rhinosinusitis Clinical Implications

“…ECRS has significantly higher association with asthma and higher incidence of aspirin sensitivity 13,14 . In our study, bronchial asthma and aspirin sensitivity were found to be more common in patients with eosinophilic polyps; the association of bronchial asthma and eosinophilic polyps was weak; and no significant statistical association between eosinophilic polyps and aspirin sensitivity.…”

Chronic Rhinosinusitis with Nasal Polyps and without Nasal Polyps is Associated with Increased Expression of Lysophosphatidic Acid–Related Molecules

“…6,7 Emerging evidence suggests a role for ATX-LPA in facilitating lymphocyte migration into lymphoid and chronically inflamed nonlymphoid tissues. 36,37 Thus, considering that inflammatory cell infiltration or exudation into the sinus mucosa appears to play an important role in the development of CRSwNPs or CRSsNPs, [38][39][40] we suggest that LPA, via LPA1-3, may play a significant role in inducing and/or sustaining the massive infiltration of inflammatory cells in human sinus mucosa. These suggestions are supported by the role of LPA receptors in airway inflammatory disease studied in vitro and in vivo.…”