The Pathophysiology of Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) is a particular leukemia subset characterized by a unique genetic lesion, i.e. the PML-RARα fusion, and an exquisite response to differentiating agents. Until the late 1980s, APL was considered the most aggressive and rapidly fatal form of acute leukemia. Over the past two decades, important advances have been made into the understanding of APL pathogenesis, as well as in its treatment, such that it has nowadays been converted into the most frequently curable leukemia in adults. APL is regarded as a model disease for the innovative tailored treatment of human leukemia, including differentiation therapy and the use of chromatin remodeling agents and antibody-directed therapy. This chapter summarizes the pathophysiology of APL with special emphasis on its impact on targeted treatment.