Elevated levels of prostaglandin E2 in the tears of patients with severe allergic conjunctivitis and primary cultured conjunctival cells are suppressed by ketotifen and dexamethasone

Abstract

Objective We examined the production of prostaglandin E2 (PGE2), which is the key prostaglandin involved in inflammatory disorders of the ocular surface. Tears and conjunctival fibroblasts were evaluated in order to assess allergic inflammation and the effect of specific drugs.Methods and analysis PGE2 was measured in tears from both patients and normal volunteers. Primary cultures of human conjunctival fibroblasts were incubated with interleukin (IL)-4 and tumour necrosis factor (TNF)-α with or without ketotifen fumarate or dexamethasone. The culture supernatants were removed 24 hours after exposure and the concentrations of PGE2 were quantified by ELISA.Results Significantly higher levels of PGE2 were observed in the tears of patients with severe allergic conjunctivitis than in those with post-surgical inflammation (p=0.02), and this production was reduced by eye drops. Stimulation with IL-4 and TNF-α induced the generation of PGE2 in supernatants of conjunctival fibroblasts, and this production was significantly downregulated by ketotifen fumarate or steroids.Conclusion PGE2 may participate in the pathogenesis of severe ocular allergic disease, and both ketotifen fumarate and steroid reduce the production of PGE2.