EOSINOPHIL GRANULE PROTEINS EXPRESSED IN OCULAR CICATRICIAL PEMPHIGOID

Background-Blister formation and tissue damage in bullous pemphigoid h ave been attributed to the release of eosinophil granule proteins-name ly, to eosinophil derived cationic protein (ECP) and major basic prote in (MBP). In the present investigation these eosinophil granule protei ns were studied in the conjunctiva of patients with ocular cicatricial pemphigoid (OCP). Methods-Conjunctival biopsy specimens obtained from patients with subacute (n=8) or chronic conjunctival disease (n=13) w ere analysed histologically and immunohistochemically using antibodies directed against EG1 (stored and secreted ECP), EG2 (secreted ECP), M BP, CD45 (common leucocyte antigen), CD3 (pan T cell marker), and HLA- DR (class II antigen). Results-Subepithelial mononuclear cells, mast c ells, and neutrophils were detected in all specimens. The number of mo nonuclear cells, neutrophils, CD45+ cells, CD3+ cells, and the HLA-DR expression were significantly higher in the subacute than in the chron ic disease group. Some eosinophils were found in specimens from five o f eight patients with subacute OCP, but in none of the patients with c hronic disease. The eosinophil granule proteins (ECP and MBP) were fou nd in the epithelium and substantia propria in patients with subacute conjunctivitis. Conclusions-Subepithelial cell infiltration in the con junctiva greatly differs between subacute and chronic ocular cicatrici al pemphigoid specimens. The findings suggest that eosinophil granule proteins may participate in tissue damage in acute phase of inflammati on in OCP.