[Studies on von Willebrand factor antigen in endothelial cells and sera of patients with connective tissue diseases].

Von Willebrand factor antigen (vWF: Ag) is known to be produced and excreted by endothelial cells (EC). The influences of interferon (IFN) on surface, excreted and intracellular vWF: Ag amounts of EC were studied by flow cytometry and ELISA. Serum levels of vWF: Ag in patients with connective tissue diseases were also studied by ELISA. Experiments in vitro showed that IFN increased vWF: Ag amounts of EC. Serum levels of vWF: Ag in patients with mixed connective tissue disease (MCTD), systemic lupus erythematosus, progressive systemic sclerosis, polymyositis/dermatomyositis or rheumatoid arthritis (RA) were significantly higher than those of normal subjects, on the other hand, vWF: Ag levels in patients with aortitis syndrome were within normal range. MCTD patients complicated with pulmonary hypertension (PH) [MCTD (PH)] and RA vasculitis (MRA) patients had quite high levels of vWF: Ag. The levels of vWF: Ag seemed to correlate with severity of PH in patients with MCTD (PH). Increased serum levels of vWF: Ag observed in those patients might be induced by EC damaged or influenced by IFN or other cytokines. Monitoring of vWF: Ag levels could be useful to predict the onset and pathologic conditions of MCTD (PH) or related vascular diseases.