Immunohistochemical localization of prostaglandin E in rheumatoid synovial tissues

Synovial tissues removed at synovectomy from patients with active rheumatoid arthritis (RA) or osteoarthritis (OA) were examined for prostaglandin E (PGE) by immunohistochemical techniques using rabbit antisera specific for PGE. Marked increments of PGE were noted in RA synovia in comparison to OA, with staining concentrated in synovial lining cells, interstitial inflammatory cells, and endothelial cells of blood vessels. A correlation was noted between the degree of synovial lymphocytic infiltrate and the intensity of PGE staining. These studies provide initial cellular localization of PGE in such tissues.