Immunohistochemical findings in prosthesis-associated giant papillary conjunctivitis

To identify functional subsets of inflammatory cells and expression of cytokines in the conjunctiva of patients with ocular prosthesis-associated giant papillary conjunctivitis (P-GPC).

Specific immunohistochemical staining using monoclonal antibodies was performed on biopsy specimens obtained from superior tarsal conjunctiva of 18 patients with P-GPC. The prosthetic eyes were taken as the study group, whereas their fellow eyes were used as matched controls.

In normal conjunctiva, mast cells (MCs) were located only in the substantia propria (SP), whereas in P-GPC eyes MCs were also notable in the epithelium in five specimens. Tryptase-chymase-positive MCs (MC(TC)) were predominant both in P-GPC (79%) and in fellow (72%) eyes. MC(TC), CD4(+) lymphocyte, CD8(+) lymphocyte and eosinophil numbers were higher in P-GPC specimens compared with the fellow eyes (P = 0.005, 0.074, 0.012 and 0.025, respectively). Eosinophils were detected in 58.8% of P-GPC specimens and 16.7% of control specimens (P = 0.053). The number of inflammatory cells expressing eotaxin and interleukin (IL)-4 was higher in P-GPC group (P = 0.050 and 0.048, respectively). Nine out of 17 giant papillary conjunctivitis specimens (52.9%) showed eotaxin and IL-4 immunoreactivity, which was considerably higher than the fellow eyes (16.7%) (P = 0.064).

These findings suggest that P-GPC is an allergic disease of the eye associated with increased numbers of MC, eosinophils and lymphocytes in the conjunctiva and a remarkable expression of IL-4 and eotaxin both by the conjunctival epithelium and by the inflammatory cells in the SP.