Rituximab in Relapsing acquired Thrombotic Thrombocytopenic Purpura: Experience and Evidence

Abstract

Thrombotic Thrombocytopenic Purpura (TTP), first described in the early twentieth century, was fatal in the majority of cases until the advent of plasma therapy. Mortality has declined dramatically since the 1980s, and in the 1990s the pathophysiology was elucidated through the discovery and understanding of the central role of a deficiency of the metalloprotease ADAMTS13. The vast majority of cases occur due to an autoimmune process, with a minority of cases due to an underlying mutation. Since the turn of this century, Rituximab, a monoclonal antibody targeting CD20 expressed on B-lymphocytes, has become widely used to treat patients with a wide spectrum of autoimmune diseases, including TTP. However, Rituximab remains “off-label” in the setting of TTP. We recently encountered a patient with chronic relapsing TTP, whose clinical relapses have responded to Rituximab-based therapy without need to resort to plasmapheresis. The clinical course of this patient is described, and the literature focusing on the use of Rituximab in prophylaxis to prevent recurrent TTP is reviewed.