Anti-endothelial cell antibodies in systemic autoimmune diseases: prevalence and clinical significance

To investigate the prevalence and characteristics of anti-endothelial cell antibodies (AECA) in a large cohort of patients with several well defined systemic autoimmune diseases, in order to determine their relationship with the clinical and laboratory features of these diseases.

Clinical and laboratory features of 216 consecutive Caucasian patients were prospectively studied. One hundred and seven patients had been diagnosed as having a primary systemic vasculitis-specifically, 39 had temporal arteritis (TA), 25 polyarteritis nodosa (PAN), 9 Wegener's granulomatosis (WG), and 34 Behcet's disease (BD)-, 90 patients had systemic lupus erythematosus (SLE), and 19 had a primary Sjogren's syndrome (SS). The AECA were determined by ELISA.

One hundred and four (48%) patients with systemic autoimmune diseases were found to have a positive titre of AECA. Specifically, AECA were detected in 41 (38%) patients with a primary systemic vasculitis (13 (33%) with TA, 14 (56%) with PAN, 5 (56%) with WG and 9 (26%) with BD), in 58 (63%) patients with SLE, and in 5 (26%) patients with a primary SS. In patients with a primary systemic vasculitis, those with AECA were found to have an increased prevalence of disease activity (P < 0.05). In SLE patients, those with AECA were found to have an increased prevalence of vascular lesions (P < 0.05), lupus nephropathy (P < 0.05), and anticardiolipin antibodies (aCL) (P < 0.001).

Patients with systemic autoimmune diseases have a high prevalence of AECA and they are associated with the presence of vascular lesions, nephropathy, and aCL in SLE, as well as with disease activity in several primary systemic vasculitis (TA, PAN, WG and BD).