Clinical bleeding events and laboratory coagulation profiles in acute promyelocytic leukemia

Bleeding is the leading cause of death for patients with acute promyelocytic leukemia (APL). Blood component transfusion to correct coagulopathy is the keystone in reducing bleeding. The benefit of fresh frozen plasma transfusion is unproven. Using laboratory profiles to predict bleeding is important guidance for the determination of transfusion policies in the treatment of APL.

For 116 patients of APL, bleeding events were collected and correlated with various hematologic and coagulation parameters, including leukemic cell percentages, white blood cell (WBC) and platelet counts, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen levels, and disseminated intravascular coagulation (DIC) scores.

Overt DIC occurred in 77.6% of patients. Severity of DIC was associated with bone marrow leukemic cell percentages but unrelated to bleeding. Patients with bleeding had significantly higher WBC counts (26.73 ± 6.18 vs. 13.03 ± 3.03 per μL, P = 0.026) and more prolonged PT (4.85 ± 0.70 vs. 2.59 ± 0.28 s, P = 0.002) and APTT (3.98 ± 1.68 vs. 0.96 ± 0.93 s, P = 0.017). Fibrinogen levels, platelet counts, and leukemia cell percentages were not significantly different between bleeding and non-bleeding patients. PT is valuable in prediction of bleeding. Patients with PT ≧ 5 s had a relative risk of 6.14 for bleeding. Seven patients had severe bleeding before initiation of all-trans retinoic acid (ATRA).

Patients with APL are susceptible to DIC and subsequent bleeding events. Prompt ATRA administration is crucial in preventing hemorrhagic events. High WBC counts, prolonged PT, and APTT are associated with clinical bleeding in our series. PT is the most accurate parameter in predicting bleeding. Based on these findings, supportive care should be directed toward correction of coagulopathy to prevent bleeding complications and fresh frozen plasma appears to be indicated for coagulopathy associated with APL.