RT Journal Article
SR Electronic
T1 Increased conjunctival expression of protease activated receptor 2 (PAR-2) in seasonal allergic conjunctivitis: a role for abnormal conjunctival epithelial permeability in disease pathogenesis?
JF British Journal of Ophthalmology
JO Br J Ophthalmol
FD BMJ Publishing Group Ltd.
SP 1304
OP 1308
DO 10.1136/bjo.2010.191221
VO 95
IS 9
A1 Yeoh, S
A1 Church, M
A1 Lackie, P
A1 McGill, J
A1 Mota, M
A1 Hossain, P
YR 2011
UL http://bjo.bmj.com/content/95/9/1304.abstract
AB Aims Aeroallergen exposure to the conjunctival epithelium in seasonal allergic conjunctivitis (SAC) may induce a cellular stress response that disrupts the barrier properties of the conjunctival epithelium, resulting in allergic disease. Whether such changes occur in SAC is unknown. Epithelial permeability is known to be increased when protease activated receptor 2 (PAR-2) is activated. We evaluated the expression of PAR-2 in patients with SAC-in-season (SACS) and compared it with control non-atopic subjects or those with out-of-season allergic conjunctivitis (OSAC).Methods Six SACS, eight normal and four OSAC specimens were examined immunohistochemically for PAR-2 and quantified in a masked fashion for the percentage of epithelia stained for each marker using Image-J software. Conjunctival epithelial heights were measured in all groups to confirm the presence of allergic eye disease.Results Mean percentage staining of PAR-2 was significantly greater in SACS that in normal specimens (73.4±15.4% vs 32.8±30.0%, p=0.038) or in OSAC (73.4±15.4% vs 1.4±2.2%, p=0.01). Mean conjunctival epithelial height was significantly raised in SACS (63.8±9.0 μm) versus controls (44.7±11.2 μm) (p=0.003, unpaired t test).Conclusions Conjunctival epithelial PAR-2 is significantly upregulated in SAC. This supports the view that disruption of the barrier properties of the conjunctival epithelium is an important event in SAC pathogenesis.