Value of endothelin-1 in rheumatoid vasculitis and synovitis

ABSTRACT

Rheumatoid vasculitis is a potentially serious complication of RA, usually occuring in long standing erosive nodular disease. It has several clinical presentations, which can be sometimes difficult to diagnose. Endothelial cells produce a variety of vasoactive substances including the potent vasoconstrictor peptide Endothelin-1 [ET-1], which has a wide range of action on mammalian tissues. ET-1 produces sustained vasoconstriction; such action may have an important pathophysiological role in initiation and development of vascular injury and hence vasculitis. Was to study plasma and synovial fluid ET-1 levels in RA and its role in pathogenesis of rheumatoid vasculitis and its correlation to disease activity in an attempt to throw light on possible new strategies in the management of this disease. We conducted our study on 30 RA patients, in addition to 10 normal healthy subjects who served as a control group. Patients and control plasma and synovial fluid samples were subjected to EIA test to measure endothelin-1 level. There was a highly significant high level of plasma ET-1 in the patient's group as compared to the control group and it was positively correlated with the presence of vasculitis in these patients and there was no correlation with the disease activity. Synovial ET-1 in the patient"s group [n = 10] was lower than their plasma level. ET-1 may play a role in pathogenesis of rheumatoid vasculitis rather than arthritis. Under this point of view, ET-1 receptor antagonist will be a novel strategy for the treatment of vasculitis associating rheumatoid arthritis