In polymyalgia rheumatica (PMR) subclinical vasculitis is suggested in the pathogenesis of the disease.1 ,2 Von Willebrand factor (vWF), produced by endothelium and megakaryocytes, is an important haemostatic factor.3In healthy people with ABO blood group O, vWF values are lower than in people with a blood group other than O.4 Increased plasma concentrations of vWF indicate endothelial damage5 and are found in diseases that involve blood vessels5 ,6 including vasculitis.7 In PMR and giant cell arteritis high vWF concentrations persist after acute phase proteins are normalised,8 ,9 but a gradual decline over time is also reported.10 ,11 Plasminogen activator inhibitor-1 (PAI-1) is an inhibitor of tissue plasminogen activator and is released from endothelial cells.12 Decreased fibrinolysis because of increased plasma concentrations of PAI-1 is associated with vasculitis in rheumatoid arthritis.7 Glucocorticoids induce PAI-1 synthesis …