Type I von Willebrand disease (vWD) is characterized by equally low plasma concentrations of von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor (RiCof) and by the presence of all vWF multimers in sodium dodecyl sulfate (SDS)-agarose gel electrophoresis. For 17 patients (13 kindreds) diagnosed with these criteria, we have studied the platelet contents of vWF:Ag and RiCof and the changes of these in plasma after DDAVP infusion. Platelet vWF:Ag and RiCof were normal in four kindreds (called “platelet normal” subgroup); following 1-deamino- 8-D-arginine vasopressin; plasma vWF:Ag, RiCof and the bleeding time (BT) became normal. In six kindreds, platelet vWF:Ag and RiCof were equally low (platelet low); after DDAVP, plasma vWF:Ag and RiCof remained low, and the BT was prolonged. In three additional kindreds, platelets contained normal concentrations of vWF:Ag, but RiCof was very low (platelet discordant); even though a complete set of multimers was found in plasma and platelets, there was a relatively small amount of large multimers. After DDAVP, plasma vWF:Ag became normal, but RiCof remained low and the BT was very prolonged. These findings demonstrated that there can be an abnormal vWF (RiCof less than vWF:Ag) even in type I vWD, coexisting with a complete set of vWF multimers (platelet discordant); that the abnormal vWF can be shown more clearly in platelets than in plasma or else in plasma after DDAVP infusion; and that DDAVP normalizes the BT only in those patients with normal platelet levels of both vWF:Ag and RiCof (platelet normal).
This study indicates that ongoing or previous infection with HBV or HCV in donor or recipient is not an absolute contraindication for BMT. However, abnormal ALT levels in BMT donors were a significant predictor of potentially lethal liver complications. The occurrence of de novo HBV or HCV infection did not correlate with severity of liver disease observed in the first 6 months posttransplant. These findings should be carefully evaluated before disregarding HBV or HCV positive siblings with normal transaminase levels in favor of unrelated donors.
Summary. 1‐deamino‐8‐D‐arginine‐vasopressin (DDAVP), was used in a wide spectrum of clinical situations employing two different dosages (0.3 and 0.4 μg/kg b. w.) for the management of 43 patients with factor VIII deficiences–mild and moderate haemophilia A and von Willebrand's disease (vWD). In most instances, the drug was given in association with antifibrinolytics. Twenty‐five dental extractions were carried out with two different protocols: one based upon a single infusion and the other based upon three infusions. Bleeding occurred in three patients regardless of the protocol used. The vasopressin analogue promptly stopped bleeding in 12 ‘spontaneous’ open bleeds (haematuria, epistaxis, menometrorrhagia, gum bleeding) and it appears to be also effective in closed bleeds. DDAVP was used to minimize blood loss during surgical interventions and to avoid haemorrhage in the postoperative period. Nine surgical procedures were carried out in six vWD patients and three haemophiliacs. Bleeding occurred late in the postoperative period on one occasion only. No difference was demonstrated between the two doses of the drug either in terms of clinical benefit or rise of factor VIII coagulant activity. The efficacy of DDAVP and the absence of side‐effects make this vasopressin analogue worthy of consideration as a reliable alternative to factor VIII concentrates in a wide variety of clinical situations.
Summary. Changes in protein C antigen (PC: Ag) have been compared with those in factor II, VII, IX and X antigens (II:Ag; VII:Ag; IX:Ag and X: Ag) in 10 patients starting on oral anticoagulant therapy with warfarin, monitored with thrombotest. Between days 0 and 3 of therapy, PC: Ag decreased at the same rate as VII: Ag, whilst IX: Ag, X: Ag and II: Ag decreased at progressively slower rates. On days 15 and 21, clotting proteins and PC: Ag did not differ significantly. Before and after warfarin, PC: Ag had the same mobility on crossed immunoelectrophoresis in Ca2+‐free agarose gel; with Ca2+, a protein with faster anodal mobility appeared on day 1 and became maximal 5 d after warfarin was started. These findings indicate that the rate of PC decrease is closer to that of factor VII than those of factors IX, X and II, and that an abnormal PC with poor Ca2+‐binding properties appears soon after treatment is started. The early decrease in the physiological inactivator (i.e. PC) might contribute to the poor antithrombotic efficacy of anticoagulant therapy during the first days.
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