VON-WILLEBRAND-FACTOR AND FACTOR-XIII IN CHILDREN WITH HENOCH-SCHONLEIN PURPURA

Levels of von Willebrand factor antigen (vWf: Ag) and factor XIII acti vity (F XIII) were studied in relation to the severity of clinical sym ptoms (scored from 0 to 3) and to immunological parameters [IgA, C3, C 4, and circulating immune complexes (CIC)] in 16 children (7 males, 9 females, aged 3-11 years) with Henoch-Schonlein purpura (HSP) at prese ntation. vWf:Ag was increased in 7 patients, F XIII activity was decre ased in 6. In all children we found high levels of IgA, while C3 and C 4 levels were normal; CIC were elevated in 11. vWf:Ag correlated with clinical score and with IgA and CIC, probably as a result of immune-me diated endothelial cell damage. The haemostatic alterations observed i n HSP are important for understanding the pathophysiology of the disea se.