Endothelin-1 and endothelin-converting enzyme-1 in chalazia

Purpose Foreign body giant cells, lymphocytes, plasma cells, and polymorphonuclear leukocytes are present within the lipogranuloma of chalazion. The aim of the present study was to investigate possible local endothelin-1 (ET-1) production by inflammatory cells and ET-converting enzyme-1 (ECE-1) expression in chalazion lesions. Methods Forty chalazia removed surgically by excision from suffering patients were studied. Chalazia were fixed in Bouin’s or formalin solution and embedded in paraffin. Chalazia sections were stained with hematoxylin and eosin for histological examination and incubated with specific antiserum for ET-1 and ECE-1 for the immunohistochemical technique. The EnVision peroxidase detection system was used and the immunoreactivity was visualized with 3-amino-9-ethylcarbazole (AEC) as a substrate. Negative controls were carried out omitting primary antibody. Results Histological analysis was carried out on chalazia at different stages of development, particularly chalazia with inflammatory cells or granulomatous structures. The epithelium of central duct and the alveoli did not immunostain for ET-1. Instead, ET-1 positive cells, specially neutrophils and macrophages were located in the stroma, around the alveoli, and within the lipogranuloma. The ECE-1 is present strongly in epithelial cells of ducts and scarcely in the secreting portion of the glands, suggesting a local ET-1 production by inflammatory cells. Conclusions Thus, the ET-1 and the putative presence of ET- receptors on neutrophils oe macrophages may provide a local source of ET-1 which might act in an autocrine/paracrine role to support granulomatous structures.