PTA (Factor XI) Levels After Transfusion in Patients with PTA Deficiency

SummaryAbetalipoproteinaemia is a rare disorder of apolipoprotein B metabolism associated with extremely low plasma concentrations of triglyce-ride. To discover whether the general positive association between factor VII and triglyceride levels extends to this condition, 5 patients were compared with 18 controls. All patients had a triglyceride below 100 μmol/l. Plasma unesterified fatty acid concentration was normal. Although factor IX activity was only slightly reduced (mean 88% standard) and factor IX antigen was normal, mean activated factor VII in patients was strikingly reduced to 34% of that in controls, a level similar to that found in haemophilia B. The patients’ mean factor VII activity and factor VII antigen were also significantly reduced to 54% and 63% of those in controls, respectively. Mean factor XI activity and tissue factor pathway inhibitor activity were reduced in patients to 70% and 75% of control values respectively, while factor XII, factor XI antigen, factor X, prothrombin and protein C were normal.

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Severe Factor XI Deficient Patient Treated with Oral Anticoagulants

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653414 ◽

1981 ◽

Vol 46 (02) ◽

pp. 568-568

Author(s):

Jan W ten Cate

Keyword(s):

Oral Anticoagulants ◽

Factor Xi ◽

Deficient Patient

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The Lupus Inhibitor: A Study of Its Heterogeneity

Thrombosis and Haemostasis ◽

10.1055/s-0038-1653464 ◽

1981 ◽

Vol 46 (04) ◽

pp. 734-739 ◽

Cited By ~ 10

Author(s):

M C Coots ◽

M A Miller ◽

H I Glueck

Keyword(s):

Systemic Lupus Erythematosus ◽

Lupus Erythematosus ◽

Inhibitory Activity ◽

Inhibition Test ◽

Clotting Factor ◽

Factor Xii ◽

Factor V ◽

Systemic Lupus ◽

Factor Xi ◽

Factor Specificity

SummaryThe plasmas of six patients with prolonged activated partial thromboplastin times were studied in detail. In five of the six, the Russell’s viper venom and prothrombin times were likewise prolonged. Five of the patients had documented systemic lupus erythematosus; one lacked the necessary criteria for this diagnosis. On quantitation, factor XI was decreased in all six; factors X and XII were diminished in five of the six. When tested for inhibitory activity, plasma from each of the patients prolonged the celite eluate inhibition test for factor XII and/or XI inhibition. In the formation of the Xa-V-phospholipid-Ca2+ complex (prothrombinase), factors X and Xa were inhibited to a greater degree than factor V or the phospholipid. Finally, each plasma was isofocused, the inhibitory fractions were identified and the clotting factor specificity of each inhibitory peak was determined.Fractions inhibitory against factors XI and XII isofocused with the IgG in each patient’s plasma. Based on the data presented from these six patients, the “lupus inhibitor” is in fact a heterogeneous collection of inhibitors directed against factors XII, XI and X rather than a homogeneous entity.

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Acquired Factor XI Inhibitors in Two Patients with Hereditary Factor XI Deficiency

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661104 ◽

1984 ◽

Vol 51 (03) ◽

pp. 371-375 ◽

Cited By ~ 10

Author(s):

Kangathevy Morgan ◽

Sandra Schiffman ◽

Donald Feinstein

Keyword(s):

Protein A ◽

Lambda Light Chain ◽

Factor Xi ◽

Spontaneous Bleeding ◽

Factor Xi Deficiency ◽

Hereditary Factor ◽

Coagulation Mechanism ◽

Factor Xia ◽

Polyclonal Igg ◽

Glass Surfaces

SummaryTwo patients with hereditary factor XI deficiency developed inhibitors following plasma transfusions. Neither had severe spontaneous bleeding. The patients’ plasmas neutralized both factor XI in plasma, purified factor XI, and purified factor XIa. The inhibitor in both patients’ plasmas adsorbed to Protein A- Sepharose. The inhibitors eluted from Protein A-Sepharose were partially neutralized by kappa and lambda light chain antisera indicating that they were polyclonal IgG antibodies. Both inhibitors markedly decreased adsorption of factor XI to glass surfaces. The cleavage of factor XI by trypsin was unaffected by the inhibitors. The lack of severe spontaneous bleeding in both of these patients strongly suggests that an alternate coagulation mechanism bypassing factor XI must compensate for this severe defect.

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