General features:
(1) negative family history of a bleeding disorder
(2) personal past history indicates normal coagulation function during childhood
(3) onset of a clinical bleeding disorder associated with a prolongation in both the PT and aPTT
(4) deficiency of factor X on coagulation factor assay
Clinical bleeding can be severe and may include:
(1) GI bleeding
(2) cutaneous bleeding
(3) intracerebral hemorrhage
Parameters to consider:
(1) isolated deficiency or mixed with other factor deficiencies
(2) deficiency of the factor or the presence of an inhibitor
A mixed acquired deficiency may occur in:
(1) liver disease
(2) vitamin K deficiency or coumadin therapy
An isolated deficiency may be seen in:
(1) amyloidosis
(2) with a circulating inhibitor
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Condition
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In Vitro Effect of Adding Normal Plasma
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amyloidosis
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PT and aPTT normal
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circulating inhibitor
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PT and aPTT prolonged
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In amyloidosis the Factor X is absorbed onto the amyloid fibrils. Therapy is directed towards reducing the amount of amyloid protein (control of underlying disease with chemotherapy; splenectomy if splenomegaly present and the patient is refractory to all therapy)..
The causes of a circulating inhibitor are uncertain but may be due to the presence of an autoantibody.
