VON-WILLEBRAND-FACTOR ANTIGEN COMPARED WITH OTHER FACTORS IN VASCULITIC SYNDROMES

In order to analyse their role as a specific marker of vascular damage and their value in monitoring disease activity the plasma concentrati ons of von Willebrand factor antigen (vWFAg) and the ristocetin cofact or (RiCoF) activities were determined in 43 children with vasculitis a nd 20 controls. These patients were subdivided into three groups accor ding to diagnosis: Henoch-Schonlein purpura (n=18), polyarteritis nodo sa (n=16), and systemic lupus erythematosus (n=9). High concentrations of vWFAg and activities of RiCoF were found in all the patient groups . vWFAg and RiCoF returned to normal as the patients became symptom fr ee and remained above normal in those with continuing symptoms. The am ount of vWFAg did not correlate with the acute phase reactants. vWFAg acted as a specific marker of vascular damage and was useful for the m onitoring of disease activity both in small vessel vasculitis and syst emic necrotising arteritis.