Anticardiolipin antibodies in systemic sclerosis: immunological and clinical associations.

Anticardiolipin antibodies of IgG/IgM class were detected in seven of 28 patients with systemic sclerosis including five of 16 patients severely affected by extensive visceral disease. This severely affected sub-group also showed significant elevations of plasma levels of von Willebrand factor antigen in 10 cases and serum C1q binding activity in seven cases respectively. This triple association raises the possibility that multiple immunological mechanisms are involved in the pathogenesis of systemic sclerosis and its vascular lesions.