Hypofibrinogenemia in non-M3 acute myeloid leukemia. Incidence, clinical and laboratory characteristics and prognosis.

Among 379 patients with AML with FAB type M1, 2 and M4-7 diagnosed between 1978 and 1997 in our institution, 19 (5%) had hypofibrinogenemia (HF), ie a fibrinogen level <180 mg/dl. Compared to patients with normal fibrinogen (n = 360) patients with HF had significantly elevated markers of activation of coagulation (TAT, F1.2, FPA) and fibrinolysis (D-dimer, FDP) indicating that disseminated intravascular coagulation/hyperfibrinolysis was the cause of hypofibrinogenemia. Patients with HF had significantly longer prothrombin times, thrombin clotting and reptilase times. Factor X and VIII were significantly lower than in patients without HF. With the exception of M7, HF occurred in all FAB subtypes, but was most common in M5 (12.1%). Patients with HF did not differ from those with normal fibrinogen with regard to age, sex, leukocyte count and other hematological parameters. During induction chemotherapy fibrinogen normalized rapidly (median 5 days) and there was no increased incidence of early hemorrhagic death. The overall and disease-free survival was similar to that of patients without HF.