Do Collectins Participate in the Pathogenesis of Certain Immune-mediated Lung Disorders?
Human SP-A and SP-D have been shown to inhibit allergen-specific IgE binding to mite extracts through lectin-dependent binding to glycoconjugates on mite allergens (13). Given that SP-A also shows lectin-dependent binding to pollens, collectins may influence the host response to a variety of inhaled organic particulate antigens. It seems reasonable to suggest that such interactions could decrease IgE-mediated mast cell activation or modulate allergen sensitization and thereby play some role in the pathogenesis of allergic asthma (13) or other immune-mediated disorders, such as hypersensitivity pneumonitis. Interestingly, the recovery of SP-A from lavage was increased by > 2-fold relative to controls in patients with hypersensitivity pneumonitis or sarcoidosis (220).