The effect of topically applied secretory leukocyte protease inhibitor on the eosinophil response in the late phase of allergic conjunctivitis.

OBJECTIVE

This study examined the effects of secretory leukocyte protease inhibitor (SLPI), a protease inhibitor in tears, in allergic conjunctivitis.

METHODS

Conjunctiva of male Hartley guinea pigs sensitized with ovalbumin were treated with SLPI or the vehicle 10 min before antigen challenge or simultaneously. The animals were sacrificed after antigen challenges of 0-24 h duration, and the inhibition of eosinophil conjunctival migration and degranulation by SLPI was analyzed histochemically. The effects of SLPI on mast cell chymase and tryptase were also examined.

RESULTS

Treatment of sensitized guinea pigs with SLPI suppressed the conjunctival recruitment and degranulation of eosinophils after antigen challenge for 6 h, inhibiting the development of allergic conjunctivitis. The effects of SLPI were observed at concentrations > or =0.1 microM, with a peak at 5 microM. SLPI inhibited chymase in a dose-dependent manner, but had no effect on tryptase.

CONCLUSIONS

The topical SLPI application may be therapeutic in allergic conjunctivitis.