PURPOSE: To analyze quantitative and structural changes in circulating von Willebrand factor (vWF) in 40 precapillary pulmonary hypertensive patients, as an attempt to identify possible correlations between endothelial cell dysfunction and patient short-term (one year) survival. METHODS: Plasma antigenic activity of vWF (vWF:Ag) was analyzed by immunoelectrophoresis. The relative concentration of vWF low molecular weight multimers (LMWM%) and the composition of vWF subunit were determined by densitometric analysis of Western blots. RESULTS: vWF:Ag was importantly increased in patients in comparison with normals (p<0.001). Patients also had increased LMWM% (p<0.001) and increased degradation of vWF main subunit (p<0.05). At the beginning of the study, nonsurvivors (N=11) had higher vWF:Ag (p<0.001) and LMWM% (p<0.005) values in comparison with survivors. LMWM% was selected by logistic regression analysis as a predictor of death during the first year of follow-up (p<0.05). CONCLUSION: Marked changes in circulating vWF likely reflect extensive pulmonary vascular endothelial cell dysfunction and are associated with poor short-term prognosis in pulmonary hypertension.
von Willebrand factor; pulmonary hypertension; endothelial cell
