Abstract
The hemostatic abnormalities seen in acute promyelocytic leukemia (APL) are unique
and account for much of the morbidity and mortality of this disorder. Almost all patients
present at diagnosis with laboratory findings of intravascular coagulation along with
increased fibrinolysis. This unusual combination is correlated to the clinical manifestations
with high risk of both bleeding and thrombosis. Recent studies have revealed that
the leukemic promyelocytes in APL express increased amounts of tissue factor as well
as elements of the fibrinolytic system, including tissue plasminogen activator, annexin
A2, and plasminogen activator inhibitor type 1. These changes are responsive to differentiation
therapy with all-trans-retinoic acid (ATRA) or with arsenic trioxide (ATO). Despite
a dramatic reduction in mortality seen since the introduction of differentiation therapy
with ATRA or with ATO, a large number of deaths still occur before complete remission
is achieved. The early deaths are mostly attributable to the presenting coagulopathy.
The prevention and management of this hemostatic abnormality have thus far been unsuccessful
and remain a challenge to bring about a higher cure rate for this disease.
Keywords
acute promyelocytic leukemia - tissue factor - fibrinolysis - tPA - annexin A2
