Increase of activated factor VIIA and haemostatic molecular markers in juvenile chronic arthritis.

Activated factor VIIa (FVIIa), von Willebrand factor antigen (vWF:Ag), D-dimer and thrombin-antithrombin III complex (TAT) were measured to monitor coagulation status in patients with juvenile chronic arthritis (JCA). Subjects included 14 patients with systemic JCA, 16 with pauciarticular JCA and 16 with polyarticular JCA without disseminated intravascular coagulopathy, thrombosis or liver dysfunction. All types of JCA showed an increase of FVIIa, D-dimer and TAT, indicating enhanced activation of coagulation. In systemic JCA only there was also characteristically an elevation of vWF:Ag. We conclude that all types of JCA constitute a state of subclinical hypercoagulopathy caused by tissue damage and that additionally systemic JCA involves a prothrombotic state associated with or precipitated by vasculitis.