Background: Surfactant-associated proteins (SP) A and D are both innate immunity mediators and produced in normal and diseased sinus mucosa. Cystic fibrosis (CF) is associated with Th1 adaptive inflammation whereas allergic fungal rhinosinusitis (AFRS) is associated with Th2 adaptive inflammation. The purpose of this study is to show and quantify the presence of SP A, SP D, tumor necrosis factor (TNF) alpha, (a Th1 marker), and eotaxin (a Th2 marker) in normal and diseased sinus mucosa.
Methods: Intraoperative sinus mucosal biopsy specimens from human volunteers were obtained during endoscopic sinus surgery for CF (n = 4), AFRS (n = 10), and normal controls (CTLs; n = 4). Specimens were evaluated for presence and quantity of SP A, SP D, and TNF-alpha using Western blot with semiquantitative immunoblot analysis. Eotaxin was quantified using ELISA immunoassay. Results were standardized and reported as picograms of mediator per microgram of total protein.
Results: SP A, SP D, and TNF-alpha levels in CF tissue extracts were 2-10 times higher than levels in AFRS tissue (with SP D and TNF-alpha reaching statistical significance) but CF tissue was not significantly higher than CTL tissue. SP A, SP D, and TNF-alpha were not significantly elevated in AFRS. Eotaxin showed elevated levels in CF and AFRS when compared with CTLs (p = 0.03 and 0.003, respectively).
Conclusion: SP D and TNF-alpha are significantly increased in CF compared with AFRS, suggesting activation of both innate immunity and Th1-mediated inflammation and potential correlation between SPs and downstream adaptive immune responses.