[State of hemostasis in hemorrhagic vasculitis in children].

The purpose of the study was to explore hemostasis in children suffering from hemorrhagic vasculitis (HV) by means of the new amidolytic methods using chromogenic substrates. The patient's plasma was studied for the content of thrombin, trypsin, factor Xa, AT-III, kallikrein, plasmin, free heparin, urokinase, factor 3 of platelets, prothrombin and Willebrand's factor. 69 children with HV were entered into the study. All of them were examined during crises. In cutaneous HV, the content of trypsin decreased 3-fold, the content of factor Xa increased 5-fold; there was a negligible increase in the plasmin and AT-III levels; the content of kallikrein rose 2-fold, that of urokinase 60-fold; the release of platelet factor 3 was intensified 1.5-fold, the activity of prothrombin 3-fold. These data indicate that in cutaneous HV, blood coagulation increased. However, the signs of disseminated intravascular coagulation were lacking because of the high blood anticoagulant activity. In mixed HV, the phase of hypercoagulation was not made for by the blood anticoagulant activity, since the latter one was depleted. The capillary toxic nephritis may give rise to disseminated intravascular coagulation associated with the depletion of the anticoagulant component. The gravity of HV and its complications can be predicted according to the characteristics of the anticoagulant component of hemostasis, especially according to the levels of urokinase and AT-III.