Hemophilia and hemophilia-like diseases caused by deficiencies in plasma thromboplastin factors: Anti-hemophilic globulin (AHG), plasma thromboplastin component (PTC) and plasma thromboplastin antecedent (PTA)

Abstract

1. 1. Clinical and coagulation studies were performed in 33 patients with hemophilia-like diseases caused by deficiencies of anti-hemophilic globulin (AHG), plasma thromboplastin component (PTC) and plasma thromboplastin antecedent (PTA). Eleven carriers were similarly studied. 2. 2. AHG and PTC deficiencies are transmitted as sex-linked recessive traits by the female to the male. PTA deficiency, on the other hand, is transmitted by either sex to both male and female children. A few carriers of mild AHG, PTC and PTA deficiencies exhibited slight bleeding tendencies and clotting defects. 3. 3. The hemorrhagic manifestations were most severe in AHG deficiency, were moderate in PTC deficiency and mildest in PTA deficiency. Joint involvement and hematuria were predominant in AHG deficiency and rare in PTA deficiency. The severity of bleeding was generally related to the degree of prolongation of clotting time for each type of defect. 4. 4. AHG deficiency was more frequently found in patients with clotting times above thirty minutes whereas PTC and PTA deficiencies were more common in patients with values below thirty minutes and in the normal range. 5. 5. Evaluation of the sensitivity of various clotting tests in the diagnosis of hemophilia-like diseases reveals that the clotting time is a relatively insensitive criterion in mild cases; the clotting time of rapidly centrifuged, platelet-poor recalcified plasma is a moderately sensitive indicator; the heparin clotting time and rate of prothrombin utilization are relatively sensitive. However, matching or mixing studies are essential for identification of the type of defect. 6. 6. A nomenclature for hemophilia and hemophilia-like diseases caused by a defect in a plasma thromboplastin factor is proposed. It is recommended that the terms anti-hemophilic globulin (AHG), plasma thromboplastin component (PTC) and plasma thromboplastin antecedent (PTA) be employed to designate both the clotting factors and their respective clinical deficiencies.