1-Deamino-8-d-arginine vasopressin: a new pharmacological approach to the management of haemophilia and von Willebrands' diseases

1-Deamino-8-d-arginine vasopressin (D.D.A.V.P.) infusion causes a marked increase in factor-VIII (antihaemophilic-factor)-related properties in patients with moderate and mild haemophilia and von Willebrand's disease (vWd). The possibility was therefore evaluated that such an autologous factor-VII response might be haemostatically effective, allowing patients to undergo surgery without plasma concentrates. 0.3 microng/kg of D.D.A.V.P. given before dental surgery and repeated in the early postoperative period was followed by a two to three fold rise in factor-VIII coagulant activity (VII C.A.) in four patients with moderate and mild haemophilia. In two, there was no abnormal bleeding after dental extraction, whereas plasma concentrates were necessary to control oozing from the sockets in the remaining two patients. A higher D.D.A.V.P. dosage (0.4-0.5 microng/kg) in patients with higherstarting VII C.A. (9% or more) was followed by a more marked response (four to six fold). VII C.A. levels up to 100% of average normal were achieved and dental extraction and major surgery (such as cholecystectomy, thoracotomy, and two tonsillectomies) were carried out successfullly in six patients with mild haemophilis and in two with vWd. The mean half-life of autologous VII C.A. was 9.4 h (range 7.5-11.6). Plasma and urine osmolality showed no consistent variation after drug administration. Thus D.D.A.V.P. appears a promision pharmacological alternative to plasma concentrates in the management of some patients with haemophilis and vWd.

Acquired storage pool disease in platelets during disseminated intravascular coagulation

A patient with clinical and laboratory evidence of disseminated intravascular coagulation associated with deep-vein thrombosis and pulmonary embolism developed a qualitative platelet abnormality characterized by a defective release reaction. Second-phase aggregation induced by ADP and adrenaline was impaired, and reduced collagen-induced aggregation was accompanied by defective release of ADP and ATP. The decrease in total platelet ATP and ADP, the high ATP:ADP ratio in the presence of normal amounts of metabolic adenine nucleotides, and the low content of serotonin associated with abnormal uptake and metabolism of the exogenous amine suggested that the defective platelet function was due to lack of the platelet organelles in which serotonin and nonmetabolic adenine nucleotides are normally stored. Acquired storage pool disease is likely to be related to exposure of circulating platelets to aggregating agents, with their degranulation occurring during disseminated intravascular coagulation.

Evaluation of prophylactic replacement therapy in haemophilia B

Prophylaxis replacement therapy has been assessed for a period of 12 months in 10 patients with severe haemophilia B showing a high incidence of spontaneous bleeding episodes. Two different schedules of administration of a freeze-dried factor IX concentrate were randomly evaluated: according to scheme A, 7.5 U/kg were administrated biweekly, whereas scheme B was based on the weekly infusion of 15 U/kg. On prophylaxis the frequency of bleeding episodes was significantly reduced (P less than 0.005) when compared with that observed in one-year period preceding the trial. Biweekly infusions were superior to weekly infusion (P less than 0.01), and the benefit appeared to be related to the higher number of days in which measurable levels of factor IX were attained in plasma. Range of motion, which was redeced at the start of the trial in 26 joints, was found to have improved in 23. Favourable changes of the joint radiological picture were observed in 6 cases. Hepatitis and factor IX inhibitors did not develop during the trial period. Side effects were rare and mild.

Asymptomatic liver disease in haemophiliacs

The incidence of jaundice and of abnormal liver function tests has been assessed in 91 multitransfused patients with severe haemophilia A and B. Tests of hepatocyte function were within the normal range in the majority of patients. On the contrary, tests of biliary cell function, liver cell damage, and bromsulphthalein retention gave high rates of abnormal values, which tended to increase with age. Hepatitis B surface antigen was present in 8% and the corresponding antibody in 66% of the cases; 18% had a history of jaundice. All patients were asymptomatic and only a minority showed clinical signs of liver involvement. These data suggest that in haemophilacs repeated and prolonged contact with the agent(s) responsible for post-transfusion hepatitis may cause chronic liver damage not associated with overt illness.