Addition of serum from patients with collagen diseases increases to cultured human endothelial cells production and release of von willebrand factor

Abstract

The addition of sera from patients with collagen diseases, particularly those with vascular complications, to the supernatant of cultured vascular endothelial cells (EC) in vitro significantly increased the surface and intracellular amounts of von Willebrand factor antigen (vWF:Ag) compared with results obtained with sera from normal healthy subjects. Peak levels of vWF:Ag occurred after 24 h of in vitro culture. Moreover, the amounts of vWF:Ag secreted into the EC supernatant with patient serum added were significantly higher than the amounts secreted into EC supernatant with control serum added, even after 48 h of in vitro culture. Levels of large and intermediate multimers (LIM) of von Willebrand factor (vWF) increased in EC supernatant exposed to serum from patients with collagen diseases as compared with levels in supernatant exposed to serum from normal controls, whereas no significant differences were detected overall between adding the plasma of patients and of normal subjects. In addition, C-reactive protein (CRP) induced a time- and dose-related release of vWF:Ag from EC, while glucocorticoid did not effect the release of vWF:Ag from EC. These results suggest that the sera of patients with collagen diseases, particularly those with vascular complications, stimulate the production and release of LIM of vWF from EC.

High dose dexamethasone increases circulating P-selectin and von Willebrand factor levels in healthy men

“…In vitro and animalstudies showedthat dexamethasone increased the immunoreactivity of vWF in different organs (6) and the thrombin stimulated release of vWF from culturedh uman vasculare ndothelial cells (7). However, dexamethasone itself does not appear to increase vWF release from culturedEC (43). These observations comparewell withour in vitro studies: we showedanincrease in vWF levels in lysates of HUVEC, butn oi ncrease in the amount of vWF released into supernatants.…”

Increased von Willebrand factor levels in patients with systemic lupus erythematosus reflect inflammation rather than increased propensity for platelet activation

“…Platelet aggregation by VWF is strongly dependent on its molecular weight, which is mainly determined by its multimeric composition 1. Large and intermediate multimers of plasma VWF are more active in platelet aggregation than dimers and may be more frequent in patients with SLE with vascular complications 33 34. This indicates that VWF multimer analysis, possibly in combination with ADAMTS13 levels that determine VWF size, could be a more relevant assay for assessing VWF-related thrombotic risk in SLE than VWF protein levels.…”