Immunohistochemical localization of somatostatin receptor sst2A in human rheumatoid synovium.

OBJECTIVE

To identify the somatostatin receptor-expressing cells in rheumatoid synovium using a recently developed antiserum directed against the somatostatin receptor subtype 2A (sst2A).

METHODS

We carried out immunohistochemical studies of synovial biopsies from 7 patients with rheumatoid arthritis (RA) and one non-RA patient, using a rabbit polyclonal antiserum directed against sst2A and monoclonal antibodies directed against phenotypic markers.

RESULTS

SSt2A was expressed by the endothelial cells of the synovial venules but also by a subset of synovial macrophages.

CONCLUSION

The identification of somatostatin receptors on macrophages, which are thought to be important effector cells in RA, may offer mechanistic insights into the potential therapeutic effect of somatostatin (analogs) in RA.