Definition
Treatment of acute promyelocytic leukaemia (APML) with arsenic trioxide (ATO) and/or all-trans retinoic acid (ATRA) can induce a potentially fatal APML differentiation syndrome.
Pathophysiology
APML differentiation syndrome is a complex cascade of pathophysiologic mechanisms caused by the release of cytokines from differentiating blast cells and pro-inflammatory cytokines, which leads to a systemic inflammatory response syndrome, endothelial damage with capillary leak syndrome, occlusion of microcirculation and tissue infiltration.r r
Incidence/prevalence
The differentiation syndrome occurs in approximately 25 percent of patients with APML during induction therapy that includes all-trans retinoic acid (ATRA, also known as tretinoin) or ATO, but it is also seen in untreated patients or after other cytotoxic therapies.
Onset/duration
APML differentiation syndrome occurs most frequently in the initial 7 to 10 days of therapy, but may occur at any time during treatment.