Thrombotic Thrombocytopenic Purpura (TTP)Lympho-PTTNCT06945861
Immunological Aspect of Thrombotic Thrombocytopenic Purpura (TTP)
An observational study of Thrombotic Thrombocytopenic Purpura (TTP), run by University Hospital, Rouen at 1 site in France.
Trial summary
The general objective of the proposed project is to characterise phenotypically and functionally ADAMTS13-specific memory B lymphocytes and autoreactive T lymphocytes, in particular follicular helper T lymphocytes, in the acute phase of the disease, but also during its progression after treatment. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Thrombotic Thrombocytopenic Purpura (TTP)
- How many people
- 44 participants
- Where
- 1 siteFrance
- Study dates
- 11 May 2023to 11 May 2028
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: patients with thrombotic thrombocytopenic purpura, whatever the stage of diagnosis (acute phase, lasting remission or not, relapse)
Who may be able to join
- age over 18
- patients with TTP at any stage of diagnosis (acute phase, lasting remission or not, relapse)
- patients undergoing internal medicine at Rouen University Hospital
- people who have read and understood the information letter
- membership of a social security scheme
Who cannot join
- a person deprived of liberty by an administrative or judicial decision or a person placed under court protection/guardianship or guardianship
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site, 1 recruiting
- Recruiting
University Rouen Hospital,
Rouen, 76031
Mathilde ML LECLERCQ, Doctor, 02 32 88 73 96 ext. +33, Mathilde.Leclercq@chu-rouen.fr
About this study
Official title: Immunological Aspects of Thrombotic Thrombocytopenic Purpura (TTP): Characterisation of B and T Lymphocytes Specific for the ADAMTS13 Autoantigen and Therapeutic Implications
The general objective of the proposed project is to characterise phenotypically and functionally ADAMTS13-specific memory B lymphocytes and autoreactive T lymphocytes, in particular follicular helper T lymphocytes, in the acute phase of the disease, but also during its progression after treatment. The aim is to highlight their contribution to the initial pathogenic process, their evolution under treatment, and also their involvement in patients who are refractory to immunosuppressive therapies and during relapses. The aim of this project is to identify early phenotypic or functional parameters that are predictive of relapse and that can be used for personalised optimisation of treatment to maintain remission.
Read the detailed description
Thrombotic thrombocytopenic purpura (TTP) is characterised by profound thrombocytopenia, haemolytic anaemia and organ dysfunction (cardiac, neurological or renal). The current treatment strategy includes plasma exchange, corticosteroid therapy, rituximab and caplacizumab, a bivalent humanised 'nanobody' targeting the A1 domain of factor Willebrand, thereby inhibiting platelet adhesion. Several response profiles to this first line of treatment have been observed: 1) durable remission profile (defined by the absence of thrombocytopenia, renal failure or clinical worsening for at least 30 days after the first day of normalisation of platelet levels), 2) refractory profile (defined by a platelet level after 4 days of intensive treatment of less than twice the initial level, associated with a persistently high level of lactate dehydrogenase), 3) relapse profile (defined by the recurrence of neurological manifestations, renal failure and/or thrombocytopenia < 100,000/mm3 for at least 2 days without any other cause identified after durable remission). The prognosis for TTP remains burdened by a mortality rate of around 10% and a relapse rate of 40-50%. The cellular players in the pathogenic process, responsible for the production of autoantibodies in this particularly severe disease, are still poorly characterised. This high-affinity memory B lymphocyte response requires cooperation with T lymphocyte players, namely follicular helper T lymphocytes. The involvement of these specific lymphocyte populations has been highlighted in the literature on other autoimmune diseases mediated by pathogenic autoantibodies, but has been little studied in TTP. The current high mortality rate in TTP suggests that a better understanding of immunopathological processes is required. Based on the model of other autoimmune diseases, this project should make it possible to identify the presence, at diagnosis, of circulating memory B lymphocytes specific for ADAMTS13, and also circulating autoreactive follicular helper T lymphocytes. After treatment with rituximab, depletion of circulating ADAMTS13-specific memory B lymphocytes is expected.
- Medical subject headings
- Purpura, Thrombotic Thrombocytopenic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Group 1: patients in the acute phase of TTP | Consultation or hospitalisation when TTP is diagnosed, before treatment is initiated | |
| Groupe 2 : patient in durable remission with ADAMTS13 activity > 10%. | Follow-up consultation | |
| Groupe 3 : patient in remission with ADAMTS13 activity < 10%. | Follow-up consultation before initiation of pre-emptive treatment | |
| Group 4: relapsing patients | Consultation or hospitalisation at the time of relapse, before treatment is initiated |
What is being measured
The primary outcome is the main question the study is designed to answer.
Identifying the presence of circulating autoreactive T lymphocytes
Identifying the presence of circulating autoreactive T lymphocytes in patients with TTP using the ELISPOT technique (Demonstration of spots indicating the presence of gamma interferon-producing T lymphocytes)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Identify the presence of circulating autoreactive B lymphocytes
Identifying the presence of circulating autoreactive B lymphocytes in patients with TTP using the ELISPOT technique (Demonstration of IL-21 spots and specific B lymphocytes producing anti-ADAMTS13 antibodies in response to the ADAMTS13 antigen)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Secondary outcomes (8)
Study quantitative variations in circulating autoreactive T lymphocytes
Study quantitative variations in circulating autoreactive T lymphocytes in patients with TTP (Definition Number of T lymphocytes producing gamma interferon and IL-21 in response to ADAMTS13 antigen as determined by ELISPOT)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Study quantitative variations in circulating autoreactive B lymphocytes
Study quantitative variations in circulating autoreactive B lymphocytes in patients with TTP (define the number of specific B lymphocytes producing anti-ADAMTS13 antibodies as determined by ELISPOT)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Determine the phenotypic characteristics of circulating autoreactive T lymphocytes
Determine the phenotypic characteristics of circulating autoreactive T lymphocytes in patients with TTP (Determination of the number of effector and memory T lymphocyte subpopulations specific for ADAMTS13 by ELISPOT)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Determine the phenotypic characteristics of circulating autoreactive B lymphocytes
Determine the phenotypic characteristics of circulating autoreactive B lymphocytes in patients with TTP (Assessment of the number of mature B lymphocyte subpopulations that are naive or memory ADAMTS13 specific)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Quantitative variations in circulating autoreactive T lymphocytes
Study quantitative variations in circulating autoreactive T lymphocytes according to the different evolutionary profiles of patients (Evaluation of the number of T lymphocytes producing gamma interferon and IL-21 in response to the ADAMTS13 antigen as determined by ELISPOT)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Quantitative variations in circulating autoreactive B lymphocytes
Study quantitative variations in circulating autoreactive B lymphocytes according to the different evolutionary profiles of patients (Evaluate the number of specific B lymphocytes producing anti-ADAMTS13 antibodies as determined by ELISPOT)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Determine the phenotypic characteristics of circulating autoreactive T lymphocytes
Determine the phenotypic characteristics of circulating autoreactive T lymphocytes in patients with TTP (Determination of the proportion of effector and memory T lymphocyte subpopulations specific for ADAMTS13 by ELISPOT)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Determine the phenotypic characteristics of circulating autoreactive B lymphocytes
Determine the phenotypic characteristics of circulating autoreactive B lymphocytes in patients with TTP (Assessment of the proportion of mature B lymphocyte subpopulations that are naive or memory ADAMTS13 specific)
Measured: At enrollment visit, Month 3, Month 6 and month 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Apr 2025
- Study start11 May 2023
- Primary completion10 May 2027 (estimated)
- Study completion11 May 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Thrombotic Thrombocytopenic Purpura (TTP)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 44 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Hospital, Rouen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06945861
- Sponsor's protocol ID
- 2022/308/OB
- Other IDs
- IDRCB : 2023-A00455-40
- Acronym
- Lympho-PTT
- Status last verified
- Apr 2026
- First submitted
- 7 Apr 2025
- Last updated
- 4 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The data provided will be the property of the sponsor and will be used solely for its own research activities.