Analysis of hypofibrinogenemias found on routine coagulation screening tests and identification of heterozygous dysfibrinogenemia or fibrinogen deficiency

: We analyzed the clinical factors resulting in hypofibrinogenemia, which is defined as less than 100mg/dl of plasma fibrinogen values determined by a procedure based on the Thrombin-time method. Within a 12-month period, we assayed 5,746 patients (19,309 plasmas) and found 113 patients (1.97%) with hypofibrinogenemia. We categorized these patients as having decreased synthesis of fibrinogen (less than 3.0g/dl of albumin, 140 IU/l of Cholinesterase, and/or 50% on Hepaplastin Test), increased consumption of fibrinogen (more than 10 microg/ml of FDP D-dimer), known side effect of L-asparaginase administration, or other causes. Details are follows: 1) decreased synthesis: 26 patients, suspected of decreased synthesis (albumin: 3.1-3.4 g/dl): 4 patients, 2) increased consumption: 15 patients, suspected of increased consumption (FDP D-dimer: 5.0-9.9 g/dl): 1 case, 3) decreased synthesis combined with increased consumption: 24 patients, suspected of decreased synthesis and/or suspected of increased consumption: 14 patients, 4) side-effect of L-asparaginase administration: 24 patients, 5) heterozygous dysfibrinogenemia: 1 patient, 6) heterozygous fibrinogen deficiency: 1 patient, suspected of heterozygous fibrinogen deficiency: 1 patient, 7) unidentified: 2 patients with West syndrome treated with a combination of ACTH and valproic acid. Three patients with dysfibrinogenemia or fibrinogen deficiency showed normal or slightly prolonged PT values and normal APTT values. These data and our previous reports suggest that heterozygous patients with dysfibrinogenemia or fibrinogen deficiency do not demonstrate markedly prolonged PT and APTT values, differing from patients with afibrinogenemia.