Rituximab as pre-emptive treatment in patients with thrombotic thrombocytopenic purpura and evidence of anti-ADAMTS13 autoantibodies

Thromb Haemost. 2009 Feb;101(2):233-8.


Thrombotic thrombocytopenic purpura (TTP) is a rare and severe disease characterized by thrombocytopenia, microangiopathic haemolytic anemia, neurological and renal involvement associated with deficiency of the von Willebrand factor-cleaving protease, ADAMTS13. Persistence of high titers of anti-ADAMTS13 autoantibodies predisposes to relapsing TTP. Since relapses are associated with high morbidity and mortality rates, the optimal therapeutic option should be a pre-emptive treatment able to deplete anti-ADAMTS13 autoantibodies and avoid relapses. Five patients who presented with persistence of undetectable ADAMTS13 activity and high titers of autoantibodies, were treated with rituximab as pre-emptive therapy during remission. Four of them were affected by relapsing TTP and one was treated after the first episode. ADAMTS13 activity ranging from 15% to 75% with disappearance of inhibitors was achieved after three months in all patients, and persisted >20% without inhibitors at six months. In three patients disease-free status is still ongoing after 29, 24 and six months, respectively. Relapses were documented in two patients during follow-up: in one patient remission lasted 51 months; while in the other patient relapse occurred after 13 months. Results demonstrated that rituximab used as pre-emptive treatment may be effective in maintaining a sustained remission in patients with anti-ADAMTS13 antibodies in whom other treatments failed to limit the production of inhibitors, and suggests that re-treatment with rituximab should be considered when ADAMTS13 activity decreases and inhibitors reappear into the circulation, to avoid a new relapse.

Publication types

  • Case Reports

MeSH terms

  • ADAM Proteins / immunology*
  • ADAMTS13 Protein
  • Adult
  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Murine-Derived
  • Autoantibodies / blood*
  • Female
  • Humans
  • Immunologic Factors / therapeutic use*
  • Male
  • Middle Aged
  • Purpura, Thrombotic Thrombocytopenic / drug therapy*
  • Purpura, Thrombotic Thrombocytopenic / enzymology
  • Purpura, Thrombotic Thrombocytopenic / immunology
  • Recurrence
  • Registries
  • Remission Induction
  • Rituximab
  • Time Factors
  • Treatment Outcome


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Murine-Derived
  • Autoantibodies
  • Immunologic Factors
  • Rituximab
  • ADAM Proteins
  • ADAMTS13 Protein
  • ADAMTS13 protein, human