Combined factor V and factor VII deficiency due to an independent segregation of the two defects.

A patient with combined factor V and factor VII deficiency is described together with a family study. The pro positus appeared to be double heterozygous for factor V and factor VII deficiency. Since the patient showed a parallel de crease of activity and antigen, he appeared to be double het erozygous for a true deficiency. The patient had inherited the factor V defect from the mother and the factor VII defect from the father. The parents of the propositus were not consanguin eous. Other family members were found to have isolated factor V or factor VII deficiency. This is the third family so far described with this peculiar combined defect but the first to be investigated by clotting and immunologic assays

Thrombosis and thrombophilia in children: a systematic review.

Thrombotic events are uncommon disorders in childhood but increasingly recognized due to the progress made in the understanding of the hemostasis system and the importance of thromboembolic disorders in children. Multiple clinical underlying conditions and prothrombotic disorders contribute to the development of thrombosis in neonates and children. In recent years programs have emerged that specialize in the diagnosis, prevention, and treatment of thrombosis in children. This review summarizes the current knowledge of the risk factors for thromboembolic events in the venous and arterial systems in children, the use of antithrombotic prophylaxis, and the role of thrombophilia. First, the clinical manifestations and the problems of diagnosing venous thromboembolic diseases and cerebrovascular diseases in children are reviewed. The prophylactic use of anticoagulants in children is also discussed. Unfortunately there are no large prospective randomized trials in children, thus guidelines are based on small studies or on extrapolation of data from adults. Second, the impact of prothrombotic defects in pediatric patients and the issue of routine testing for these disturbances are reviewed

Factor VIIa-antithrombin complexes in patients with arterial and venous thrombosis.

Antithrombin (AT), in the presence of heparin, is able to inhibit the catalytic activity of factor VIIa bound to tissue factor (TF) on cell surfaces. The clinical meaning of FVIIa-AT complexes plasma levels is unknown. It was the objective of this study to evaluate FVIIa-AT complexes in subjects with thrombosis. Factor VIIa-AT complexes plasma levels in 154 patients consecutively referred to our Department with arterial or venous thrombosis and in a group of 154 healthy subjects, were measured. Moreover, FVIIa-AT complexes were determined in: i) n = 53 subjects belonging to 10 families with inherited factor VII deficiency; ii) n = 58 subjects belonging to seven families with AT deficiency; iii) n = 49 patients undergoing oral anticoagulant therapy (OAT). Factor VIIa-AT levels were determined by a specific ELISA kit (R&D, Diagnostica Stago, Gennevilliers, France). Factor VIIa-AT complexes mean plasma levels were lower in patients with either acute arterial (136 +/- 40 pM) or venous (142 +/- 53 pM) thrombosis than subjects with previous thrombosis (arterial 164 +/- 33 pM and venous 172 +/- 61 pM, respectively) and than healthy controls (156 +/- 63 pM). Differences between acute and previous thrombosis, were statistically significant (p < 0.05). Subjects with inherited and acquired (under OAT) factor VII deficiency had statistically significant lower FVIIa-AT complexes plasma levels (80 +/- 23 pM and 55 +/- 22 pM, respectively) than controls (150 +/- 51 pM, p < 0.0001 and 156 +/- 63 pM, p < 0.00001, respectively). Factor VIIa-AT complexes are positively correlated with plasma factor VII/VIIa levels. Further investigations are needed to verify the possible role of higher FVIIa-AT complex plasma levels in predicting hypercoagulable states and thrombosis