Acquired Thrombotic Thrombocytopenic PurpuraNCT05046717
Improvement of Immunologic and Molecular Techniques for the Diagnosis and Follow-up of Patients With Thrombotic Thrombocytopenic Purpura
An observational study of Acquired Thrombotic Thrombocytopenic Purpura, run by Fundación Española de Hematología y Hemoterapía at 6 sites in 2 countries.
Trial summary
The lack of ADAMTS13 is the only biological marker that is specific for aTTP diagnosis8 and the assessment of ADAMTS13 is of clinical importance because it is essential for the rapid differential diagnosis between aTTP and other TMA. Read more about this study
- Who is it for?
- Ages 0 to 99 years
- Conditions the study is for
- Acquired Thrombotic Thrombocytopenic Purpura
- What is being tested?
- ADAMTS13 Activity Assays
- Type of treatment
- Medical device
- How many people
- 500 participants
- Where
- 6 sitesin 2 countries
- Study dates
- 13 Oct 2022to Jun 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 0 to 99 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: The study population will be all consecutive patients who meet the following inclusion criteria and none of the following exclusion criteria until reaching the number of patients determined for the study.
Who may be able to join
- Patients with confirmed thrombotic microangiopathy (TMA) based on citrated blood samples meeting both of the following criteria:
- Thrombocytopenia [drop in platelet count ≥50% or platelet count < 100x109/L and
- Microangiopathic haemolytic anaemia (elevation of lactate dehydrogenase (LDH) >2- fold or by presence or increase of schistocytes in peripheral blood smear)
- Patients that voluntarily sign informed consent. For subjects unable to provide consent, a fully recognized medical proxy may be used according to local laws.
- Patients between 0 to 99 years old at the time of screening.
Who cannot join
- -
Trial locations and contacts
6 sites in 2 countries.
6 sites in 2 countries
Spain5 sites
Complejo Hospitalario Universitario A Coruña
A Coruña, A Coruña, 15006
Hospital Clinic de Barcelona
Barcelona
Hospital Clínico San Carlos
Madrid
Hospital Gregorio Marañon
Madrid
Hospital La Fe de Valencia
Valencia
Portugal1 site
Centro Hospitalar e Universitario de Coimbra
Coimbra, Coimbra District, 3004-561
About this study
Official title: Improvement of Immunologic and Molecular Techniques for the Diagnosis and Follow-up of Patients With Thrombotic Thrombocytopenic Purpura: a Collaborative Study Proposal of the Spanish Apheresis Group (GEA) in Collaboration With the Spanish Foundation of Hematology and Hemotherapy (FEHH)
The lack of ADAMTS13 is the only biological marker that is specific for aTTP diagnosis8 and the assessment of ADAMTS13 is of clinical importance because it is essential for the rapid differential diagnosis between aTTP and other TMA. Furthermore, monitoring of ADAMTS13 activity is useful to ensure biological remission (ADAMTS13 levels > 10%) as well as predicting relapses.
Due to the high mortality rate of aTTP, treatment should be started as soon as the disease is suspected, sometimes even before confirmation with the ADAMTS13 test results. This situation may lead to misdiagnose some patients and leave them without the appropriate treatment. In conclusion, ADAMTS13 activity assay is crucial for an early diagnosis and optimal management of acute aTTP and any delay in ADAMTS13 results will have a negative impact on the diagnosis, treatment and prognosis of the patient.
Read more
There are currently 2 techniques available for the ADAMTS13 activity determination, the fluorescence resonance energy transfer (FRET) and the Technozym chromogenic enzyme-linked immunosorbent assay (ELISA). Both are considered reference methods but they require considerable skill because they are highly manual and this increases the risk of error. Furthermore, these methods are time-consuming, not widely available and, in case of the ELISA method, it requires a new calibration at each run. The inter-laboratory variability is also a challenge and therefore a validation and/or interpretation method could be needed.
Recently, a new and first fully automated HemosIL AcuStar ADAMTS13 Activity assay (Instrumentation Laboratory, Bedford, Massachusetts, United States) has been developed. HemosIL AcuStar ADAMTS13 Activity assay is a two steps chemiluminescent immunoassay (CLIA) with an analytical time of 33 minutes for the quantitative measurement of ADAMTS13 activity in human-citrated plasma on the ACL AcuStar analyser. The immunoassay uses the GST-VWF73 substrate in combination with magnetic particles for rapid separation and chemiluminescence technology detection. The ADAMTS13 present in the plasma sample cleavages the GST-VWF73 substrate and the detection of the generated fragments is based upon an isoluminol-labelled monoclonal antibody that specifically reacts with the cleaved peptide. The emitted light is proportional to the ADAMTS13 activity in the sample.
This new ADAMTS13 assay method has been compared with the other two available techniques in two different studies. First, Favresse et al. published the results of the comparison between Technozym activity ELISA assay and the new HemosIL AcuStar chemiluminescent assay. On the other hand, Valsecchi et al. have recently published the results of validation of this new technique in comparison with ELISA and FRETS in 176 samples. Both studies conclude that the new chemiluminescent ADAMTS13 activity assay showed a good correlation and excellent clinical performance for the diagnosis of severe ADAMTS13 deficiency with the FRETS-VWF73 assay and a commercial ELISA when considering only ADAMTS13 activity values below 10% (the internationally accepted cut-off for a diagnosis of severe ADAMTS13 deficiency typical of aTTP). Finally, Stratmann et al. have just published another study comparing the HemosIL AcuStar chemiluminescent assay with two commercially available ADAMTS13 assay kits using 24 paired test samples derived from 10 consecutively recruited patients13 and their results corroborate the previously published data suggesting that the AcuStar assay could be a valuable and accurate tool for ADAMTS13 activity testing and aTTP diagnostic.
In this context, a unique opportunity to validate this new technique is generated, both retrospectively with our already available data from frozen samples and also in the context of a large prospective study. This will be the first study worldwide testing HemosIL AcuStar method in real clinical practice aTTP population (Spanish and Portuguese aTTP populations) with the aim to standardize the diagnosis and follow-up methodology for the disease.
- Being tested
- ADAMTS13 Activity Assays
- 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.
ADAMTS13 Activity AssaysDevice
In this study the measurement of ADAMTS13 activity will be assessed with three different commercial kits:
- HemosIL AcuStar ADAMTS13 Activity Assay (Instrumentation Laboratory, Bedford, Massachusetts, United States)
- ELISA, DG-EIA ADAMTS13 Activity (Diagnostic Grifols®, Spain)
- FRETS-VWF73 for ADAMTS13 Activity Assay
Three kits will be used with all patients.
What is being measured
The primary outcome is the main question the study is designed to answer.
Correlation of a new diagnostic test and standard test
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Measured: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test and standard test
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Measured: At follow up (10 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test and standard test
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Measured: At follow up (30 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test and standard test
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Measured: At follow up (60 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test and standard test
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Measured: At follow up (90 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test and standard test
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Measured: At follow up (180 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test and standard test
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Measured: At follow up (365 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Secondary outcomes (21)
Concordance of classification of aTTP
To evaluate the concordance of classification of aTTP patients at diagnosis based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
To evaluate the concordance of classification of aTTP patients based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (10 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
To evaluate the concordance of classification of aTTP patients based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (30 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
To evaluate the concordance of classification of aTTP patients based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (60 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
To evaluate the concordance of classification of aTTP patients based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (90 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
To evaluate the concordance of classification of aTTP patients based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (180 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
To evaluate the concordance of classification of aTTP patients based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (365 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
To evaluate the sensitivity and specificity of classification of aTTP patients visits based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
To evaluate the sensitivity and specificity of classification of aTTP patients visits based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (10 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
To evaluate the sensitivity and specificity of classification of aTTP patients visits based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (30 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
To evaluate the sensitivity and specificity of classification of aTTP patients visits based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (60 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
To evaluate the sensitivity and specificity of classification of aTTP patients visits based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (90 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
To evaluate the sensitivity and specificity of classification of aTTP patients visits based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (180 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
To evaluate the sensitivity and specificity of classification of aTTP patients visits based on HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS.
Measured: At follow up (365 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Clinical characteristics
Describe clinical characteristics of patients with TMA at the diagnosis and those with aTTP at the diagnosis and follow up based on ADAMTS13 cut-off < 10%.
Measured: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Clinical characteristics
Describe clinical characteristics of patients with TMA at the diagnosis and those with aTTP at the diagnosis and follow up based on ADAMTS13 cut-off < 10%.
Measured: At follow up (10 days)
Clinical characteristics
Describe clinical characteristics of patients with TMA at the diagnosis and those with aTTP at the diagnosis and follow up based on ADAMTS13 cut-off < 10%.
Measured: At follow up (30 days)
Clinical characteristics
Describe clinical characteristics of patients with TMA at the diagnosis and those with aTTP at the diagnosis and follow up based on ADAMTS13 cut-off < 10%.
Measured: At follow up (60 days)
Clinical characteristics
Describe clinical characteristics of patients with TMA at the diagnosis and those with aTTP at the diagnosis and follow up based on ADAMTS13 cut-off < 10%.
Measured: At follow up (90 days)
Clinical characteristics
Describe clinical characteristics of patients with TMA at the diagnosis and those with aTTP at the diagnosis and follow up based on ADAMTS13 cut-off < 10%.
Measured: At follow up (180 days)
Clinical characteristics
Describe clinical characteristics of patients with TMA at the diagnosis and those with aTTP at the diagnosis and follow up based on ADAMTS13 cut-off < 10%.
Measured: At follow up (365 days)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Sep 2021
- Study start13 Oct 2022
- Primary completion14 Nov 2025
- Study completionJun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Acquired Thrombotic Thrombocytopenic PurpuraStudies 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Fundación Española de Hematología y Hemoterapía
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05046717
- Sponsor's protocol ID
- INSPIRER
- Status last verified
- Feb 2026
- First submitted
- 8 Sep 2021
- Last updated
- 11 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Improvement of Immunologic and Molecular Techniques for the Diagnosis and Follow-up of Patients With Thrombotic Thrombocytopenic Purpura: a Collaborative Study Proposal of the Spanish Apheresis Group (GEA) in Collaboration With the Spanish Foundation of Hematology and Hemotherapy (FEHH)
- ClinicalTrials.gov ID
- NCT05046717
- Acronym / sponsor ID
- INSPIRER
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 500 participants (estimated)
- Lead sponsor
- Fundación Española de Hematología y HemoterapíaUniversity, hospital or other
- Study start
- 13 Oct 2022 (actual)
- Primary completion
- 14 Nov 2025 (actual)
- Study completion
- Jun 2026 (estimated)
- First posted
- 16 Sep 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The lack of ADAMTS13 is the only biological marker that is specific for aTTP diagnosis8 and the assessment of ADAMTS13 is of clinical importance because it is essential for the rapid differential diagnosis between aTTP and other TMA. Furthermore, monitoring of ADAMTS13 activity is useful to ensure biological remission (ADAMTS13 levels > 10%) as well as predicting relapses.
Due to the high mortality rate of aTTP, treatment should be started as soon as the disease is suspected, sometimes even before confirmation with the ADAMTS13 test results. This situation may lead to misdiagnose some patients and leave them without the appropriate treatment. In conclusion, ADAMTS13 activity assay is crucial for an early diagnosis and optimal management of acute aTTP and any delay in ADAMTS13 results will have a negative impact on the diagnosis, treatment and prognosis of the patient.
There are currently 2 techniques available for the ADAMTS13 activity determination, the fluorescence resonance energy transfer (FRET) and the Technozym chromogenic enzyme-linked immunosorbent assay (ELISA). Both are considered reference methods but they require considerable skill because they are highly manual and this increases the risk of error. Furthermore, these methods are time-consuming, not widely available and, in case of the ELISA method, it requires a new calibration at each run. The inter-laboratory variability is also a challenge and therefore a validation and/or interpretation method could be needed.
Recently, a new and first fully automated HemosIL AcuStar ADAMTS13 Activity assay (Instrumentation Laboratory, Bedford, Massachusetts, United States) has been developed. HemosIL AcuStar ADAMTS13 Activity assay is a two steps chemiluminescent immunoassay (CLIA) with an analytical time of 33 minutes for the quantitative measurement of ADAMTS13 activity in human-citrated plasma on the ACL AcuStar analyser. The immunoassay uses the GST-VWF73 substrate in combination with magnetic particles for rapid separation and chemiluminescence technology detection. The ADAMTS13 present in the plasma sample cleavages the GST-VWF73 substrate and the detection of the generated fragments is based upon an isoluminol-labelled monoclonal antibody that specifically reacts with the cleaved peptide. The emitted light is proportional to the ADAMTS13 activity in the sample.
This new ADAMTS13 assay method has been compared with the other two available techniques in two different studies. First, Favresse et al. published the results of the comparison between Technozym activity ELISA assay and the new HemosIL AcuStar chemiluminescent assay. On the other hand, Valsecchi et al. have recently published the results of validation of this new technique in comparison with ELISA and FRETS in 176 samples. Both studies conclude that the new chemiluminescent ADAMTS13 activity assay showed a good correlation and excellent clinical performance for the diagnosis of severe ADAMTS13 deficiency with the FRETS-VWF73 assay and a commercial ELISA when considering only ADAMTS13 activity values below 10% (the internationally accepted cut-off for a diagnosis of severe ADAMTS13 deficiency typical of aTTP). Finally, Stratmann et al. have just published another study comparing the HemosIL AcuStar chemiluminescent assay with two commercially available ADAMTS13 assay kits using 24 paired test samples derived from 10 consecutively recruited patients13 and their results corroborate the previously published data suggesting that the AcuStar assay could be a valuable and accurate tool for ADAMTS13 activity testing and aTTP diagnostic.
In this context, a unique opportunity to validate this new technique is generated, both retrospectively with our already available data from frozen samples and also in the context of a large prospective study. This will be the first study worldwide testing HemosIL AcuStar method in real clinical practice aTTP population (Spanish and Portuguese aTTP populations) with the aim to standardize the diagnosis and follow-up methodology for the disease.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 0 to 99 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- The study population will be all consecutive patients who meet the following inclusion criteria and none of the following exclusion criteria until reaching the number of patients determined for the study.
Key inclusion criteria (5 listed)
- Patients with confirmed thrombotic microangiopathy (TMA) based on citrated blood samples meeting both of the following criteria:
- Patients that voluntarily sign informed consent. For subjects unable to provide consent, a fully recognized medical proxy may be used according to local laws.
- Patients between 0 to 99 years old at the time of screening.
Key exclusion criteria (1 listed)
- -
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ADAMTS13 Activity AssaysIn this study the measurement of ADAMTS13 activity will be assessed with three different commercial kits: 1. HemosIL AcuStar ADAMTS13 Activity Assay (Instrumentation Laboratory, Bedford, Massachusetts, United States) 2. ELISA, DG-EIA ADAMTS13 Activity (Diagnostic Grifols®, Spain) 3. FRETS-VWF73 for ADAMTS13 Activity Assay Three kits will be used with all patients. | Device | – |
Primary outcome
Correlation of a new diagnostic test and standard test
Time frame: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Correlation of a new diagnostic test and standard test
Time frame: At follow up (10 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Correlation of a new diagnostic test and standard test
Time frame: At follow up (30 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Correlation of a new diagnostic test and standard test
Time frame: At follow up (60 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Correlation of a new diagnostic test and standard test
Time frame: At follow up (90 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Correlation of a new diagnostic test and standard test
Time frame: At follow up (180 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
Correlation of a new diagnostic test and standard test
Time frame: At follow up (365 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Correlation of a new diagnostic test, HemosIL AcuStar chemiluminescent assay, in comparison with ELISA and/or FRETS in the measurement of activity and antibody of ADAMTS13 in IU/mL
21 secondary outcomes
Concordance of classification of aTTP
Time frame: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
Time frame: At follow up (10 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
Time frame: At follow up (30 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
Time frame: At follow up (60 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
Time frame: At follow up (90 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
Time frame: At follow up (180 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Concordance of classification of aTTP
Time frame: At follow up (365 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
Time frame: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
Time frame: At follow up (10 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
Time frame: At follow up (30 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
Time frame: At follow up (60 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
Time frame: At follow up (90 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
Time frame: At follow up (180 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Sensitivity and specificity of classification of aTTP
Time frame: At follow up (365 days) of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Clinical characteristics
Time frame: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).
Clinical characteristics
Time frame: At follow up (10 days)
Clinical characteristics
Time frame: At follow up (30 days)
Clinical characteristics
Time frame: At follow up (60 days)
Clinical characteristics
Time frame: At follow up (90 days)
Clinical characteristics
Time frame: At follow up (180 days)
Clinical characteristics
Time frame: At follow up (365 days)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Feb 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
6 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Acquired Thrombotic Thrombocytopenic Purpura, run by Fundación Española de Hematología y Hemoterapía at 6 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 11 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in Spain, Portugal. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Correlation of a new diagnostic test and standard test (time frame: At diagnosis of patients with acquired thrombotic thrombocytopenic purpura (aTTP).). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Feb 2026.