What type of leukemia is most commonly associated with disseminated intravascular coagulation (DIC) as a presenting disorder?

Disseminated Intravascular Coagulation as a Presenting Disorder in Leukemia

Acute promyelocytic leukemia (APL) is the type of leukemia most commonly associated with disseminated intravascular coagulation (DIC) as a presenting disorder. 1

Pathophysiology and Prevalence

APL, a subtype of acute myeloid leukemia (AML), is characterized by:

• Translocation t(15;17)(q24.1;q21.1) forming the PML-RARA fusion gene 1
• High prevalence of coagulopathy at presentation, with DIC occurring in 17-100% of APL cases 2
• Severe hemorrhagic complications that can be life-threatening 1

The prevalence of DIC varies significantly between leukemia subtypes:

• 17-100% in APL
• 8.5-25% in non-APL AML and acute lymphoblastic leukemia (ALL) 2

Laboratory Characteristics Distinguishing APL-associated DIC

APL with DIC has distinct laboratory findings compared to other AML subtypes with DIC:

• Higher levels of:

  • Fibrin degradation products (FDP): 77.7 μg/mL vs. 23.7 μg/mL
  • D-dimer: 7,376.2 ng/mL vs. 1,315.2 ng/mL

• Lower levels of:

  • Fibrinogen: 133.8 mg/dL vs. 373.2 mg/dL
  • WBC count: 14.988×10⁹/L vs. 70.755×10⁹/L 3

Clinical Implications and Management

The clinical presentation of DIC varies between leukemia subtypes:

• APL: Predominantly hemorrhagic complications
• Non-APL AML and ALL: More thrombotic manifestations 2

Management Approach

1. Early recognition and treatment initiation:

   • Start ATRA immediately upon suspicion of APL, without waiting for genetic confirmation 1, 4
   • Early ATRA administration prevents lethal bleeding complications 1, 4

2. Treatment regimens:

   • Low/intermediate-risk APL: ATRA (45 mg/m² in 2 divided doses daily) + arsenic trioxide (ATO) 1, 4
   • High-risk APL: ATRA combined with anthracycline-based chemotherapy 4

3. Supportive care for DIC:

   • Maintain platelet counts at minimum 30-50 G/L
   • Keep fibrinogen in normal range (100-150 mg/dL) 4
   • Monitor for APL differentiation syndrome 1

Important Considerations

• Early mortality risk: Approximately 30% of APL patients die during induction, primarily due to hemorrhagic complications 5
• Intracranial hemorrhage: A particularly dangerous complication of APL-associated DIC 6
• Monitoring: Regular assessment of coagulation parameters is essential during treatment 7

Pitfalls to Avoid

1. Delayed treatment: Never wait for molecular confirmation before starting ATRA in suspected APL 1, 4
2. Premature assessment: Avoid premature morphologic and molecular assessment (day 10-14 marrow) as it can be misleading 1
3. Inconsistent regimens: Use treatment regimens consistently through all components; do not mix induction from one protocol with consolidation from another 1
4. Inadequate monitoring: Closely monitor for APL differentiation syndrome and DIC throughout treatment 1, 7

The answer to the multiple-choice question is B. Acute promyelocytic leukemia.