Differentiation Syndrome in APML Epidemiology: • Incidence: common in APL (2-48% depending on the study) • Triggers: ATRA treatment Pathophysiology: • Cytokine Release from blast cells → SIRS response • Cathepsin G release → vascular permeability and endothelial damage • Induce blast cell adhesion and endothelial damage Prophylaxis: • Attempt if high risk if WBC > 5 or elevated Cr • Prednisone 5mg/kg/day vs. 2.5 mg/m2 Presentation: Subacute-Acute: • Common: fever, myalgias, HoTN, edema and effusions, weight gain. More common in severe • Rare: DAH, acute febrile neutrophilic dermatosis Diagnosis: • Labs: leukocytosis and coagulopathy common • Imaging: CXR- pulmonary opacities • Diagnosis: >3 symptoms, or> 1 with no other explanation. Moderate > 2/3 and severe >4. Timing, generally either within 6 days or 15 days of ATRA initiation • Differential Diagnosis: Infection (sepsis), PE, DAH, CHF, Anaphylaxis, Acute Renal Failure Treatment: • Steroids: IV Dexamethasone 10 mg q12h -> 10 mg q6h • Cytoreductive: hydroxycarbamide 500 mg QD until normal WBC • Continue ATRA unless severe APLS, organ dysfuxtion, ICU, refractory to steroids • Supportive Care: Diuresis for fluid overload, PCC to reverse coagulopathy, RRT/IMV as needed - Dr. Noah Rosenberg @nsrosenberg #Differentiation #Syndrome #APML #diagnosis #management #hematology #oncology
