SIGNIFICANCE OF SURFACTANT PROTEIN-A IN CHRONIC RHINOSINUSITIS

Abstract

BackgroundandObjective: Surfactant protein-A (SP-A) is a hydrophobicprotein secreted within
pulmonary surfactant that facilitates the adsorption of surface-active lipids to theair-liquid interface of
the alveoli and increases alveolarstability. SP-A may also have anti-inflammatory properties. It is
implicated in decreasing the pulmonary inflammatory response to bacterial lipopolysaccharide.
However, the expression and function of SP-A in the human nasal tissue has not been elucidated. Our
objective was to detect the presence of SP-A, measure alterations in several forms of chronic
rhinosinusitis (CRS).
Patients and methods:Inferior turbinate and sinus mucosal biopsies were takenfrom 15 patients
with chronic sinusitis,15 patients with primary atrophic rhinitis,and 10 healthy controls.
Immunohistochemical staining for SP-A and polymerase chain reaction amplification of SP-A
messengerRNAwere performed on samples of nasal tissues.
Results:Immunostaining localized SP-A to the mucosaand submucosal glands in specimensof chronic
bacterial sinusitis,while failed to localize it in primary atrophic rhinitis. Quantitativepolymerase chain
reaction showed significantly increased levels of SP-A patients with chronic bacterial sinusitiswhen
compared with controls (P<0.0001), also demonstrated significant reduction of SP-A in patients of
primary atrophic rhinosinusitis when compared with control(P= 0.0225).
Conclusion:SP-A is significantly increased in chronic bacterial rhinosinusitis,decreased significantly
in primary atrophic rhinitis and appears to be expressed by respiratory epithelial cells and submucosal
glandular elements of the sinonasal mucosa. Further characterization of this specialized protein is
warranted considering the potential therapeutic applications of surfactant in the enhancement of
mucociliary clearance.