Thrombotic thrombocytopenic purpura-what is new?

A functional deficiency of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif), a von-Willebrand factor (VWF) cleaving protease, is central to the pathogenesis of congenital and acquired thrombotic thrombocytopenic purpura (TTP). ADAMTS13 testing has evolved from assays that required long denaturation and incubation times to ones that employ a modified recombinant VWF with improved standardization and turn around times. While plasma exchange is a mainstay in the treatment of TTP, increased use of rituximab, an antibody against CD20, has proved helpful in the treatment of patients with exacerbations and relapses. The next generation of drugs focuses on using recombinant ADAMTS13 and molecules that block the interaction of VWF and platelets to prevent thrombotic microangiopathy. The increased awareness and availability of ADAMTS13 testing has also made it possible to detect atypical presentations of TTP such as patients with macrovascular neurological symptoms without accompanying hematological findings as well as help diagnose other causes of thrombotic microangiopathies e.g. atypical hemolytic uremic syndrome. The use of ADAMTS13 testing in the management of TTP should continue to grow especially with newer assays with greater sensitivity, reproducibility, and timelier availability.