Comparison of laboratory characteristics between acute promyelocytic leukemia and other subtypes of acute myeloid leukemia with disseminated intravascular coagulation

BACKGROUND: Acute promyelocytic leukemia (APL) is an acute myeloid leukemia (AML) subtype with distinctive cell morphology, molecular presentation, clinical course, and treatment. About 90% of APL patients present with hemorrhagic complications due to disseminated intravascular coagulation (DIC). When APL is suspected, all-trans retinoic acid (ATRA) treatment is recommended even before confirmation by molecular tests. Specific criteria for differentiating unconfirmed APL from other AML subtypes with DIC are currently lacking. We aimed to achieve the early diagnosis of APL from other AML types with DIC by restricting the DIC criteria. METHODS: We retrospectively analyzed 29 patients newly diagnosed with AML accompanied by DIC from January 2005 to January 2013. RESULTS: Fibrin degradation products (FDP) (77.7 µg/mL vs. 23.7 µg/mL, p=0.026), D-dimer (7,376.2 ng/mL vs. 1,315.2 ng/mL, p=0.018), and TIBC (264.4 µg/dL vs. 206.8 µg/dL, P=0.046) were higher, while fibrinogen (133.8 mg/dL vs. 373.2 mg/dL, p<0.001), WBC (14.988×10(9)/L vs. 70.755×10(9)/L, p=0.015), and ESR (7.1 mm/h vs. 50.0 mm/h, p <0.001) were lower in APL patients than in the patients with other AML subtypes. FDP ≥27 µg/mL, D-dimer ≥2,071 ng/mL, and fibrinogen ≤279 mg/dL were our threshold values. These markers may be characteristic to APL and helpful in presumptive diagnosis. CONCLUSION: APL may be differentiated from other AML subtypes by core markers of DIC (FDP, D-dimer, and fibrinogen). We suggest that clinicians set new diagnostic thresholds by restricting the DIC criteria. These findings support the early initiation of ATRA, prior to confirmation by PML-RARA molecular testing.