[Abnormal blood coagulation and fibrinolysis in chronic myeloproliferative disorders]

Thirty-six patients with chronic myeloproliferative disorders (CMPD) were studied as regards blood coagulation and fibrinolysis. These studies revealed various mild abnormalities: activated thromboplastin time (APTT) tended to prolong and the level of factor V decreased significantly. In several cases, the levels of D-dimer, thrombin-antithrombin III complex and plasmin-alpha 2-plasmin inhibitor complex were elevated compared to normal. These results suggest that abnormal coagulation system in the patients with CMPD is related to low grade disseminated intravascular coagulation. Many coagulation factors did not correlate with peripheral blood cell counts. Two patients with polycythemia vera were evaluated for several abnormalities of the coagulation system before and during treatment. Coagulation abnormalities persisted after hematologic control had been achieved. Our results suggest that patients with CMPD have a chronic state of abnormal blood coagulation system even after normalization of blood cell counts.