Evidence-based medicine for apheresis: an ongoing challenge

Although much has been learned about the pathophysiologic process of thrombotic thrombocytopenic purpura (TTP) since Moschcowitz's initial description in 1924, its etiology and treatments remain problematic. We treated our first patient with TTP by plasma exchange in 1975 and have now treated over 160 patients. We report our experience exchanging patients using FFP, solvent detergent (SD) and cryopoor plasma as the exchange media. Most patients experience allergic reactions, some severe, during the course of treatment. However, use of SD plasma virtually eliminates all allergic reactions. Splenectomy was a much more common treatment prior to plasma exchange, but can still be a useful treatment option for some refractory patients. Recombinant ADAMTS-13 can hopefully provide not only more useful diagnostic assays but also could provide specific and more efficacious treatment of patients with both acquired and familial forms of TTP.