Polycythaemia vera and Christmas disease with slightly prolonged prothrombin time

Area of Science:

• Hematology
• Clinical Pathology
• Genetics

Background:

• Christmas disease (hemophilia B) and polycythemia vera are distinct hematological disorders.
• The one-stage prothrombin time is a crucial test for assessing blood coagulation.
• Factor VII deficiency is a rare bleeding disorder affecting blood clotting.

Purpose of the Study:

• To investigate the association between Christmas disease, polycythemia vera, and prolonged one-stage prothrombin times.
• To explore the nature of the prothrombin time abnormalities observed in these conditions.

Main Methods:

• Case reporting of a family with Christmas disease and polycythemia vera.
• Analysis of one-stage prothrombin times in affected individuals and their siblings.
• Utilizing "mixing procedures" to assess the interaction of plasma factors.

Main Results:

• Prolonged one-stage prothrombin times, consistent with factor VII deficiency, were identified in a family member with Christmas disease and another with polycythemia vera.
• Similar prothrombin time alterations were noted in siblings of the Christmas disease patient.
• Unrelated patients diagnosed with polycythemia vera also exhibited these clotting time changes.
• Mixing studies did not demonstrate significant correction of the prolonged prothrombin times, indicating a complex underlying mechanism.

Conclusions:

• The findings suggest a potential link between factor VII deficiency-like prothrombin time abnormalities and both Christmas disease and polycythemia vera.
• The observed clotting time changes in relatives and unrelated polycythemia vera cases warrant further investigation into potential genetic or shared etiological factors.
• The lack of correction in mixing studies highlights the complexity of the observed coagulation defect.