The effect of immediate-hypersensitivity reactions on the level of SLPI, granulocyte elastase, alpha(1-)antitrypsin, and albumin in nasal secretions,by the method of unilateral antigen challenge

Background: The aim of this paper was to investigate the role of SLPI in pa tients with allergic rhinitis. From this point of view, we also examined le ukocyte elastase, alpha(1)-antitrypsin, and albumin. SLPI is an inhibitor of serine proteases such as leukocyte elastase, cathep sin G, and mast-cell chymase. Since chymase is considered to participate in mast-cell degranulation and histamine release, SLPI might act as a regulat or of allergic reactions. Recent interest has been focused on leukocytes an d allergy. Since SLPI is a strong inhibitor of leukocyte elastase, we also focused on the function of elastase in allergic rhinitis. Methods: We used the method of nasal lavage after unilateral nasal antigen challenge in atopic and healthy subjects. The ELISA quantified SLPI and ela stase. Albumin and alpha(1)-antitrypsin were quantified by electroimmunoass ay. Gel filtration was used to separate native SLPI from its complex with e lastase. Results: There was a higher level of SLPI in ravage fluid from healthy subj ects than from atopic patients. SLPI was increased on the contralateral sid e in atopic subjects after allergen challenge. The absence of increase in S LPI on the challenged side may be attributed to the increase in elastase an d its binding to SLPI, which might have an effect on the immunoreactivity a nd interfere with the ELISA. It may then be assumed that there is an augmen tation of SLPI on the challenged side as well. No increase was seen in heal thy subjects. There was a higher concentration of elastase, alpha(1)-antitr ypsin, and albumin before antigen challenge in atopic patients outside the pollen season than in healthy subjects. As expected, an increase was also s een in the challenged side exclusively in atopic subjects. Conclusions: The lower concentration of SLPI in nasal lavage fluid among th e atopic patients than the healthy subjects indicates damaged mucosa. Neura l reflexes are involved in SLPI release since there was an increase even in the contralateral nostril. A higher level of elastase and albumin before a llergen challenge suggests chronic inflammation in nasal mucosa outside the pollen season. Leukocyte recruitment takes place in response to IgE-mediat ed reactions, which are reflected in an increase in elastase in response to allergen challenge.