An observational study in Thrombotic Thrombocytopenic Purpura (TTP), sponsored by University Hospital, Rouen. Recruiting at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-04.
Sponsored by University Hospital, Rouen · Observational
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.
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.
67 studies on the registry are indexed under Purpura, Thrombotic Thrombocytopenic; 18 are open to participants now.
This study's planned enrollment of 44 is below the median of 156 across 27 observational studies indexed under Purpura, Thrombotic Thrombocytopenic.
Browse Purpura, Thrombotic Thrombocytopenic studies →University Hospital, Rouen is the lead sponsor of 418 studies on the registry; 106 are open to participants now.
Counted across the registry records on this site, refreshed daily.
patients with thrombotic thrombocytopenic purpura, whatever the stage of diagnosis (acute phase, lasting remission or not, relapse)
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
- a person deprived of liberty by an administrative or judicial decision or a person placed under court protection/guardianship or guardianship
Consultation or hospitalisation when TTP is diagnosed, before treatment is initiated
Follow-up consultation
Follow-up consultation before initiation of pre-emptive treatment
Consultation or hospitalisation at the time of relapse, before treatment is initiated
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)
Time frame: 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)
Time frame: At enrollment visit, Month 3, Month 6 and month 12
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)
Time frame: 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)
Time frame: 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)
Time frame: 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)
Time frame: 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)
Time frame: 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)
Time frame: 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)
Time frame: 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)
Time frame: At enrollment visit, Month 3, Month 6 and month 12
Plan to share: No — The data provided will be the property of the sponsor and will be used solely for its own research activities.
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Purpura, Thrombotic Thrombocytopenic →