Comparative incidence of thrombosis in reported cases of deficiencies of factors of the contact phase of blood coagulation.

Thrombotic manifestations occurring in patients with coagulation defects have drawn considerable attention during the last decade. It concerned mainly patients with hemophilia, vW disease or FVII deficiency. Occasional reports involved also the deficiencies of the contact phase of blood coagulation, mainly FXII deficiency. The purpose of the present study was to evaluate the comparative incidence of thrombosis in all reported patients with FXII, Prekallikrein and Kininogens deficiencies. Out of the reported 341 cases with these conditions that could be tracked there were 43 cases with thrombosis. More specifically, there were 32 patients with FXII deficiency who also had a thrombotic event (16 arterial and 16 venous). As far as Prekallikrein deficiency is concerned, there were nine cases with thrombosis (five arterial and four venous). Finally, two patients with Total or High molecular weight Kininogen deficiencies had also a thrombotic manifestation (one arterial and one venous). The thrombotic manifestations were M.I. 11 cases; ischemic stroke 9 cases; peripheral arteries 3 cases; deep vein thrombosis with or without pulmonary embolism 17 cases; thrombosis in other veins 3 cases. Congenital or acquired associated prothrombotic risk factors were present in 33 out of 36 cases. In three cases the existence of associated risk factors was excluded whereas in the remaining seven patients no mention is made in this regard. This study clearly indicates that the severe in vitro coagulation defect seen in these conditions does not protect from thrombosis.