Long-term management of acquired thrombotic thrombocytopenic purpura using serial plasma ADAMTS13 measurements.

Although significant advances in the understanding of TTP pathophysiology have been made in the last 15 yr, none have yet impacted the empiric treatment paradigm for this disease for which plasmapheresis is the mainstay. Laboratory assays for ADAMTS13 activity and inhibitors can be used to confirm a clinical diagnosis, but the assays are not routinely used to guide treatment. The routine availability of ADAMTS13 testing has allowed our group to tailor plasmapheresis and immunosuppressive therapy in patients under active treatment for TTP. In addition, the concept of establishing immune tolerance, similar to the eradication of a factor VIII inhibitor in patients with congenital or acquired hemophilia, has emerged as an important strategy to prevent early relapse of TTP. With the expected incorporation of recombinant ADAMTS13 into the treatment algorithm over the next several years, we anticipate that readily available ADAMTS13 testing will play an important role in individualized therapy that incorporates enzyme replacement and establishment of immune tolerance.