Objective: Surfactant protein A (SP-A) is protein that appears to play an important role in mammalian first-line host defense. The objective of this study was to immunolocalize SP-A in human sinonasal tissue.
Method: Eleven cases of allergic rhinitis, fifteen cases of polyp and seven cases of normal middle turbinate were studied with immunohistochemistry and immunofluorescence method to detect the expression of SP-A.
Result: The expression of SP-A in allergic rhinitis and polyp were dramatically higher than that in controls (P < 0.05), and there was no remarkable difference in the expression of SP-A between allergic rhinitis and polyp (P > 0.05). The result demonstrated that SP-A was positively correlated with eosinophils within the basement membrane of epithelium (R = 0.81, 0.55). In the result of immunofluorescence, there was significantly higher expression SP-A in nasal mucosa of allergic rhinitis and nasal polyp than that in control group (P < 0.05).
Conclusion: SP-A is likely to play key roles in the inflammatory reaction process of allergic rhinitis and polyp. Its secretion in the upper airway indicates that future studies may allow manipulation of this protein and development of novel treatments for sinonasal pathology.