Hereditary heparin cofactor II deficiency and thrombosis: report of six patients belonging to two separate kindreds.

We describe six patients belonging to two families with congenital heparin cofactor II deficiency (HC II). The affected members had low levels of HC II antigen and activity, and no abnormalities in HC II electrophoretic mobility were detected in the presence of heparin or dermatan sulphate during the first migration of crossed immunoelectrophoresis. These data suggested that patients had a type I (true) HC II deficiency.

Heterozygous protein-S deficiency: a study of a large kindred.

Another family with protein-S deficiency is described here. The defect is characterized by a reduced level of total protein-S antigen; in addition, a markedly reduced level of free protein-S antigen was found. We have studied 20 family members.

Partial gene deletion in a family with factor X deficiency.

The presence of gene lesions in coagulation factor X (FX, Stuart factor) was investigated in patients with FX deficiency or an FX abnormality (FX Friuli). The proposita had a heterozygous partial deletion of the FX gene with severe deficiency of FX activity and antigen. The lesion, which was inherited from her mother, removes the 3' portion of the gene coding for the catalytic domain of the factor.

Effects of glycosaminoglycans and protamine chloridrate on platelet aggregation induced by collagen and thrombin.

The effects of heparin (HE), dermatan sulfate (DS), heparan sulfate (HS) and protamine chloridrate (PC) on platelet aggregation were studied. Both PC and the three glycosaminoglycans (GAGs) did not influence collagen-induced platelet aggregation. In contrast, all the tested GAGs blocked thrombin-induced platelet aggregation.

Severe arterial cerebral thrombosis in a patient with protein S deficiency (moderately reduced total and markedly reduced free protein S): a family study.

Deficiency of protein S has been associated with an increased risk of thrombotic disease as already shown for protein C deficiency. Deficiencies of any of these two proteins predispose to venous thrombosis but have been only rarely associated with arterial thrombosis. In this study we describe a case of severe cerebral arterial thrombosis in a 44-year old woman with protein S deficiency.

The report of an Italian family with heterozygous protein C deficiency.

A heterozygote protein C deficit was found in 4 members of the same family. The propositus is a 40 year old male with a clear thrombotic tendency. This included repeated thrombophlebitis of the right leg, and one episode of pulmonary embolism.

Factor X antigen--factor X activity discrepancy in coumarin treated patients. No relationship with dilution curve.

The plasma of 12 patients on coumarin medication was investigated with regard to factor X antigen, factor X activity, factor X antigen--factor X activity difference (delta) and dilution curve. The plasmas were divided into 3 groups according to the level of anticoagulation (under anticoagulated, normally anticoagulated, over anticoagulated). The average factor X antigen and the average factor X activity were 56.