International Working Group on TTP
Advancing TTP science through global collaboration.
IWG TTP brings together clinicians, investigators, and collaborators worldwide to advance research, strengthen scientific consensus, and improve the shared understanding of immune-mediated and congenital thrombotic thrombocytopenic purpura.
InternationalConnecting expertise across borders
Investigator-ledBuilt around scientific contribution
CollaborativeProjects, working groups, and shared data
IndependentScientific decisions remain independent
What we do
International expertise focused on shared scientific priorities.
IWG TTP is designed to move international collaboration forward efficiently—bringing together the people, expertise, and scientific priorities needed to address challenges that are difficult to solve within any single country or institution.
01 / Research
Collaborative Research
Develop and support international studies and project teams focused on high-impact, feasible questions in TTP and related TMAs.
02 / Consensus
Scientific Consensus
Bring experts together to refine terminology, outcomes, definitions, and other scientific frameworks that strengthen research and clinical communication.
03 / Exchange
Education & Exchange
Create settings where clinicians and investigators can discuss emerging evidence, practical challenges, and new scientific questions.
04 / Community
Global Collaboration
Connect investigators, institutions, registries, professional societies, and advocacy organizations across an international network.
Scientific priorities
Current scientific priorities.
The 2026–2027 scientific agenda includes terminology and outcome definitions, congenital TTP, recombinant ADAMTS13 surveillance, evolving iTTP treatment strategies, and collaborative studies and publications.
TTP terminology and outcome definitions
Building on prior international consensus work to keep definitions meaningful as treatments, monitoring, and clinical practice evolve.
Congenital TTP and recombinant ADAMTS13
Discussing event definitions, long-term manifestations, surveillance approaches, and emerging scientific questions around recombinant ADAMTS13.
Evolving iTTP treatment strategies
Examining how new therapies and plasma-exchange-sparing strategies affect treatment pathways, outcomes, and future guidance.
Collaborative studies and publications
Creating a practical pathway for member-proposed projects, investigator-led working groups, publications, and future proceedings.
Scientific work in development: Topics discussed by IWG TTP working groups are not final clinical guidance unless formally approved and published by the organization.
Latest from IWG TTP
News, meetings, and scientific updates.
IWG TTP Shares Updated Monitoring Proposal for Patients Receiving Adzynma
The International Working Group on TTP (IWG TTP) has developed an updated proposal for monitoring patients with congenital thrombotic thrombocytopenic purpura (cTTP) who receive ADAMTS13 replacement therapy with Adzynma. The proposal was revised following discussion by the IWG TTP Advisory Board during the 2026 ISTH Congress in Paris. The work follows reports of anti-ADAMTS13 antibodies…
Looking ahead: planning the next IWG TTP scientific meeting
The next international gathering is being planned around ASH 2026, with final details to follow.
Consensus spotlight: redefining outcomes in immune TTP
A look back at the 2021 international consensus report that updated iTTP outcome definitions for a changing treatment landscape.
Membership and participation
Contribute to international TTP research and scientific collaboration.
IWG TTP welcomes clinicians, scientists, investigators, and collaborators who are actively engaged in TTP/TMA care, research, or related work. Members can participate in meetings, contribute to projects and working groups, and help shape future scientific initiatives.