Consensus on the standardization of terminology in thrombotic thrombocytopenic purpura and related thrombotic microangiopathies

J Thromb Haemost. 2017 Feb;15(2):312-322. doi: 10.1111/jth.13571. Epub 2017 Jan 30.


Essentials An international collaboration provides a consensus for clinical definitions. This concerns thrombotic microangiopathies and thrombotic thrombocytopenic purpura (TTP). The consensus defines diagnosis, disease monitoring and response to treatment. Requirements for ADAMTS-13 are given.

Summary: Background Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) are two important acute conditions to diagnose. Thrombotic microangiopathy (TMA) is a broad pathophysiologic process that leads to microangiopathic hemolytic anemia and thrombocytopenia, and involves capillary and small-vessel platelet aggregates. The most common cause is disseminated intravascular coagulation, which may be differentiated by abnormal coagulation. Clinically, a number of conditions present with microangiopathic hemolytic anemia and thrombocytopenia, including cancer, infection, transplantation, drug use, autoimmune disease, and pre-eclampsia and hemolysis, elevated liver enzymes and low platelet count syndrome in pregnancy. Despite overlapping clinical presentations, TTP and HUS have distinct pathophysiologies and treatment pathways. Objectives To present a consensus document from an International Working Group on TTP and associated thrombotic microangiopathies (TMAs). Methods The International Working Group has proposed definitions and terminology based on published information and consensus-based recommendations. Conclusion The consensus aims to aid clinical decisions, but also future studies and trials, utilizing standardized definitions. It presents a classification of the causes of TMA, and criteria for clinical response, remission and relapse of congenital and immune-mediated TTP.

Keywords: ADAMTS-13 protein, human; diagnosis, differential; thrombocytopenia; thrombotic microangiopathy; thrombotic thrombocytopenic purpura.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAMTS13 Protein / blood
  • Adult
  • Blood Platelets / metabolism
  • Child
  • Complement System Proteins
  • Consensus
  • Diagnosis, Differential
  • Erythrocytes / metabolism
  • Female
  • Fibrin / chemistry
  • Hematology / standards*
  • Hemolysis
  • Hemolytic-Uremic Syndrome / diagnosis
  • Humans
  • Inflammation
  • Platelet Aggregation
  • Platelet Count
  • Pregnancy
  • Purpura, Thrombotic Thrombocytopenic / diagnosis*
  • Recurrence
  • Remission Induction
  • Societies, Medical
  • Terminology as Topic
  • Thrombotic Microangiopathies / diagnosis*
  • Treatment Outcome
  • von Willebrand Factor / metabolism


  • von Willebrand Factor
  • Fibrin
  • Complement System Proteins
  • ADAMTS13 Protein
  • ADAMTS13 protein, human