Seasonal allergic conjunctivitis Is associated with increased conjunctival epithelial height & upregulation of both PAR 2 & HSP 70 Protein

Purpose: : To evaluate the distribution/expression of PAR 2 & HSP 70 in patients with SC in season (SCS) and compare to non-atopic subjects & out of season allergic conjunctivitis (OSC) patients.Methods: : Conjunctival biopsies were collected from 8 SCS & 7 normals (non-atopic). Sections were embedded in glycol methacrylate (photographed using Leica DMRBE) & examined for CE heights using light microscopy & computer assisted imaging software. A standard 1mm stage scale at x10 magnification was used to measure CE heights from the basement membrane to the apical surface of the epithelium. Measurements were taken at 1 cm interval.In 6 SCS, 8 normal and 4 OSC patient specimens, section were examined immunohistochemically for PAR 2 and HSP 70. Immunohistochemical expression was quantified for the percentage of epithelia stained using Image-J software. This analysis was done in a masked fashion.Results: : Mean CE percentage staining of PAR 2 in SCS, normals & OSC was 75.0 + 15.4 %, 32.8 + 30.0 % & 1.36 + 2.2 % respectively. The degree of staining in SCS was significantly greater when compared to normals (P= 0.038) or OSAC (P=0.01) groups (using Mann-Whitney U test). Mean CE percentage staining of HSP 70 in SCS, normals & OSC were 73.3 + 22.2 %, 50.3 + 34.1% &22.0 + 7.8%, respectively. Again, HSP 70 expression in SCS was found to be significantly greater in comparison to OSC (P= 0.013, Mann-Whitney U test). There was no difference in HSP 70 expression between normal & OSC. Mean CE heights were significantly raised in SCS (63.8 + 9.0 µm) compared to controls (44.7 + 11.2 µm) (P=0.003, two-tailed unpaired t test).Conclusions: Both PAR 2 & HSP 70 proteins are significantly up-regulated in SCS, in the presence of elevation of CE heights. This data suggest that both the physical and immunological character of the CE are significantly altered in SCS. These changes may have an important role in the pathogenesis in Allergic Eye Disease