Carboxypeptidase A3 Expression In Intraepithelial Mast Cells Of Chronic Allergic Conjunctivitis

Abstract

Purpose: : Carboxypeptidase A3 (CPA3) is a protease known to be expressed in mast cells. Preferential CPA3 expression in intraepithelial mast cells in atopic asthma was reported previously. We investigated the expression of CPA3 in the giant papillae obtained from vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) patients.

Methods: : 10 giant papillae were resected for therapeutic purpose and frozen sections were prepared as previously described. (IOVS.50:2871-2877) Anti-CPA3/anti-tryptase or anti-CPA3/anti-chymase double immnunohistochemical staining was carried out by indirect immunofluorescent method.

Results: : CPA3-tryptase double immunostaining showed that CPA3 positive staining was observed in the intraepithelial tryptase positive mast cells. CPA3-chymase double immunostaining showed both CPA3+ chymase- mast cells and CPA3+ chymase+ mast cells in the conjunctival epithelium of the giant papillae samples. CPA3+ chymase+ mast cells tend to be located at near the epithelial-stromal borders.

Conclusions: : Preferential CPA3 expression in the intraepithelial mast cells of giant papillae was observed. MC_T mast cells are predominant mast cell type for CPA3 expression. CPA3 expression may relate to mast cell activation or maturation.

Keywords: conjunctivitis