Screening Tests for Bleeding Disorders

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Abstract
Results of laboratory tests to detect a bleeding state in 526 patients with various established hemorrhagic disorders have led to the following conclusions. In hemophilia and factor K (PTC) deficiency, the most sensitive tests employed were the partial thromboplasgtn time, thromboplastin generation test, and specific assays for factor vm (AHG) or K. Other techniques, such as the coagulation time in glass or silicone tubes or the prothrombin consumption test, were significantly less sensitive in detecting the presence of a clotting defect. In the detection of the heterozygous state for factor K deficiency, the specific assay for factor IX was the most sensitive of the various methods tested; results were abnormal in 80% of subjects. In 2 patients with acute promyelocytic leukemia (a rare form in which promyelocytes predominate in the blood and marrow), severe hypofibrinogenemia was prominent. This was not seen in 86 patients with other forms of leukemia studied. In myelofibrosis, the bleeding time (Ivy method) was prolonged in 9 of 10 patients despite normal platelet counts; this may have been related to the reduced in vivo platelet adhesiveness seen in 1/2 of the patients studied. The bleeding time and the platelet adhesiveness test are valuable in detecting hemostatic abnormalities in a miscellaneous group of nonthrombocyto-penic disorders, in addition to von Willebrand''s disease and myelofibrosis, and in a number of patients without other known disorders.