SP-A plays an integral part in the innate defense system. SP-A
expression and function are altered in a variety of inflammatory
and infectious diseases. However, the presence of SP-A in
the human paranasal sinus mucosa is not well known.7
There are few previous studies investigating surfactant
and SP in the upper airway.10 The presence of lamellar bodies
and SP-A, -B, and -D have been described in the porcine
eustachian tube, indicating that a surfactant-like system is
present outside the pulmonary system.11 Woodworth et al
demonstrated the presence of lamellar bodies, SP, and mRNA
in both diseased and normal human sinus tissue and reported
that SP-A and SP-D immunolocalized to the sinonasal epithelium
and submucosal gland secretory ducts.12