Surfactant proteins in inflammatory skin diseases: controlled study.

Surfactant proteins (SP) have recently been reported to be expressed in human skin tissue. SP is thought to play an essential role in the firstline defense of skin. In this study, we aimed to investigate if the SP may play a role in inflammatory skin diseases. Seven volunteers with psoriasis (n = 3), atopic dermatitis (n = 2), lichen planus (n = 1) and Behcet's disease (n = 1) participated in the study. Biopsies from each lesion and adjacent (approximately 2 cm distant) normal-appearing skin in patients were performed. Expression and localization of the SP-A, -B, -C, and -D in fresh tissues were studied by an immunohistochemical technique. In all patients, there was a weak cytoplasmic staining with SP-A and SP-D and nuclear staining with SP-B and SP-C in the epidermis of normal-appearing skin samples. However, epidermal staining with SP was observed to be stronger in all lesional samples. In addition, there was a prominent staining in inflammatory cells infiltrating dermis. This expression represents a previously unknown immunologic response in the inflammatory skin diseases and may represent an important step in the pathogenesis of these disorders.