What are appropriate initial and salvage therapies for patients with thrombotic thrombocyopenic purpura (TTP)?

Although much has been learned about the pathophysiologic process of thrombotic thrombocytopenic purpura (TTP), both diagnostically and therapeutically, since its initial description by Moschowitz in 1924, its etiology and treatments remain, in many instances, problematic. Thrombotic thrombocytopenic purpura remains a rare entity whose etiology is usually unknown, but several drugs and infections have now been implicated in its development. Although treatment by plasma exchange has gained worldwide acceptance, the optimal exchange media is not known, nor the volume and duration of exchange therapy, not appropriate salvage therapies. Without the benefit of randomized controlled trials, its treatment, to a large extent, remains not evidence-based but "eminence-based", making the same mistakes with increasing confidence over decades.