Transfusion
-
National guidance recommends planning for future blood shortages, but few studies have evaluated how reduced demand could be achieved acutely. ⋯ In institutions with patterns of blood use similar to ours, control of transfusions to medical patients is the most effective response to acute blood shortages.
-
Storage can negatively impact the hemostatic potential of platelet concentrates (PCs) used for transfusion. At the site of vascular injury, normal platelets (PLTs) are hypothesized to change into highly procoagulant-coated PLTs upon costimulation with collagen and thrombin. We investigated whether activated recombinant factor VII (rFVIIa, NovoSeven, Novo Nordisk A/S) could improve the ability of stored PLTs to support coagulation under conditions that promote the formation of coated PLTs. ⋯ rFVIIa accelerated thrombin and clot formation throughout storage, with the most pronounced effect observed in the PCs that had been stored for the shortest length of time (Day 1). Resistance to fibrinolysis was gradually impaired throughout the storage period and was not affected by the addition of rFVIIa.
-
Case Reports
Anti-von Willebrand factor aptamer ARC1779 for refractory thrombotic thrombocytopenic purpura.
Plasma exchange is the main therapy for thrombotic thrombocytopenic purpura (TTP). No treatments other than plasma exchange have been documented to be effective nor are approved for treatment of TTP. The anti-von Willebrand factor (VWF) aptamer ARC1779 effectively inhibits VWF activity in plasma samples of TTP patients and thus shear-dependent platelet (PLT) function as measured by the PLT function analyzer PFA-100 (Dade Behring). It was hypothesized that ARC1779 would offer a potentially effective treatment option for a critically ill patient, refractory to standard care. ⋯ ARC1779 caused a clear and reproducible increase in PLT counts in an otherwise refractory TTP case. These clinical, pharmacokinetic, and pharmacodynamic data provide a rational basis for clinical trials with ARC1779 in TTP.