DrepanocytosisDREPA-COGNCT07168447
Transfusion Exchanges and Cognition in Sickle Cell Disease
An observational study of Drepanocytosis and Chronic Neurological Deficiency, run by Centre Hospitalier St Anne at 6 sites in France.
Trial summary
DREPA-COG is an observational study evaluating the effect of exchange transfusions on cognitive function in adults with severe sickle cell disease (SS or Sβ0). Information processing speed is assessed at three time points during the transfusion cycle using the Symbol Digit Modalities Test (SDMT) and additional… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Drepanocytosis, Chronic Neurological Deficiency
- How many people
- 85 participants
- Where
- 6 sitesFrance
- Study dates
- 3 Dec 2025to 2 Nov 2027
- How long will I take part?
- 6 Weeks
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The study population consists of adults aged 18 years or older with severe sickle cell disease (SS or Sβ0) who are enrolled in a regular monthly transfusion exchange program. Participants must not be institutionalized, must have no known dementia or severe aphasia, and must be able to communicate in French. They must also be affiliated with a social security system. Excluded are individuals with severe comorbidities that could interfere with short-term follow-up, those with known psychiatric disorders, participants in other ongoing clinical studies with exclusion periods, individuals lacking adequate computer equipment for remote assessments, and vulnerable patients under legal protection such as guardianship or curatorship. This population allows evaluation of cognitive processing speed and other neuropsychological outcomes in a controlled, transfusion-managed cohort of adult sickle cell patients.
Who may be able to join
- Adults (≥18 years) with severe sickle cell disease (SS or Sβ0).
- Enrolled in a regular monthly transfusion exchange program.
- Not institutionalized.
- No known dementia.
- No severe aphasia.
- Affiliated with or beneficiary of a social security system.
Who cannot join
- Insufficient mastery of spoken French.
- Severe comorbidities preventing short-term follow-up.
- Known psychiatric disorders.
- Participation in another clinical study with ongoing exclusion periods.
- Lack of adequate computer equipment (minimum 11-inch screen and internet connection).
- Vulnerable patients under legal protection (guardianship or curatorship).
Trial locations and contacts
6 sites in 1 country. Contact the study team or a site near you to ask about taking part.
6 sites in 1 country
France6 sites
Assistance Publique - Hôpitaux de Paris Hôpital Avicenne
Bobigny, Île-de-France Region, 93000
Sylvain LE JEUNE, DOCTOR, 01 48 95 51 41 ext. +33, sylvain.le-jeune@aphp.fr
Hôpital Henri Mondor
Créteil, Île-de-France Region, 94000
Fatima BENSIRADJ, DOCTOR, 0149812443 ext. +33, fatimazohra.bensiradj@aphp.fr
Hôpital Kremlin-Bicêtre
Le Kremlin-Bicêtre, Île-de-France Region, 94 275
Corinne GUITTON, DOCTOR, 01 45 21 32 54 ext. +33, corinne.gujtton@aphp.fr
GHU Paris Psychiatrie et Neurosciences - Hôpital Sainte-Anne
Paris, Île-de-France Region, 75014
Assistance Publique - Hôpitaux de Paris Hôpital Necker
Paris, Île-de-France Region, 75015
Laure JOSEPH, DOCTOR, 01 44 49 55 91 ext. +33, laure.joseph@aphp.fr
Centre Hospitalier Saint-Denis
Saint-Denis, Île-de-France Region, 93200
Stéphanie NGO, DOCTOR, 0142356140 ext. +33, stephanie.ngo@ch-stdenis.fr
stephanie NGO, DOCTOR
About this study
Official title: Effect of Exchange Transfusions on Cognitive Efficiency in Patients With Sickle Cell Disease
DREPA-COG is an observational study evaluating the effect of exchange transfusions on cognitive function in adults with severe sickle cell disease (SS or Sβ0). Information processing speed is assessed at three time points during the transfusion cycle using the Symbol Digit Modalities Test (SDMT) and additional validated neuropsychological measures. This minimal-risk, fully remote study aims to identify processing speed as a reproducible marker for clinical monitoring and future therapeutic trials.
Read the detailed description
DREPA-COG is a non-interventional, multicenter observational study investigating the effect of exchange transfusions on cognitive performance in adults with severe sickle cell disease (SS or Sβ0). Cognitive complications, including slowed information processing and executive dysfunction, are frequent and disabling in this population. Exchange transfusion, a standard therapy replacing sickled red blood cells with donor cells, may positively influence cognition, but systematic evidence is lacking.
The study evaluates information processing speed as a potential neurological marker across the transfusion cycle. Participants complete three brief neuropsychological assessments remotely by videoconference: before the transfusion, one week after, and prior to the next transfusion. The Symbol Digit Modalities Test (SDMT) is the primary measure, complemented by validated assessments of global cognition, attention, memory, fatigue, mood, and pain.
Primary analysis will use mixed-effects models to assess changes in processing speed over time, adjusting for demographic and clinical covariates. This minimal-risk, fully remote study requires no additional hospital visits and aims to establish processing speed as a reproducible and clinically relevant outcome measure in sickle cell disease.
- Conditions
- Drepanocytosis, Chronic Neurological Deficiency
- Keywords
- Sickle cell disease, cognitive function, neuropsychological assessment, transfusion exchange, non-interventional study, executive function, SDMT, T-MoCA, fatigue, anxiety, depression
- Medical subject headings
- Sickle Cell Trait, Anemia, Sickle Cell, Fatigue, Anxiety Disorders, Depression
What is being measured
The primary outcome is the main question the study is designed to answer.
Information Processing Speed
Primary outcome measure: Information processing speed, assessed using the oral version of the Symbol Digit Modality Test (SDMT), as a marker of cerebral involvement in adult patients with sickle cell disease.
Measured: 48 hours before the transfusion exchange
Information Processing Speed
Primary outcome measure: Information processing speed, assessed using the oral version of the Symbol Digit Modality Test (SDMT), as a marker of cerebral involvement in adult patients with sickle cell disease.
Measured: 7 to 9 days after the transfusion exchange
Information Processing Speed
Primary outcome measure: Information processing speed, assessed using the oral version of the Symbol Digit Modality Test (SDMT), as a marker of cerebral involvement in adult patients with sickle cell disease.
Measured: within 48 hours before the next scheduled transfusion exchange
Secondary outcomes (6)
Global Cognitive Function - Montreal Cognitive Assessment (Telephone version, T-MoCA)
The T-MoCA is a validated screening tool for global cognition, adapted for telephone administration. Scores range from 0 to 22, with higher scores indicating better cognitive performance.
Measured: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Fatigue Severity Score (FSS)
Fatigue will be assessed using the Fatigue Severity Scale (FSS), a validated self-administered questionnaire consisting of 9 items, each rated on a 7-point Likert scale (1 = strongly disagree; 7 = strongly agree).
The total score is the mean of the 9 items, ranging from 1 (no fatigue) to 7 (severe fatigue).
Higher scores indicate more severe fatigue and represent a worse outcome.
Measured: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Anxiety and Depression Symptoms (Hospital Anxiety and Depression Scale, HADS
The Hospital Anxiety and Depression Scale (HADS) is a validated self-report questionnaire consisting of 14 items, divided into two subscales: Anxiety (HADS-A, 7 items) and Depression (HADS-D, 7 items). Each subscale score ranges from 0 to 21, with higher scores indicating more severe symptoms.
Measured: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Pain Intensity (Numeric Rating Scale, NRS)
Pain intensity will be assessed using the Numeric Rating Scale (NRS), a validated self-report tool where participants rate their pain on a scale from 0 to 10.
0 = no pain
10 = worst imaginable pain Higher scores indicate greater pain intensity.
Measured: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Change in Information Processing Speed Measured by the Symbol Digit Modalities Test (SDMT)
Information processing speed will be assessed using the Symbol Digit Modalities Test (SDMT), a standardized neuropsychological test that evaluates attention, visual scanning, and motor speed. The test provides a raw score, which reflects the number of correct pairings completed within a 90-second period.
Higher scores indicate better information processing speed.
This measure aims to evaluate changes in SDMT scores across the transfusion cycle and identify individual variability in performance.
Measured: Within 48 hours before exchange transfusion 7-9 days after exchange transfusion Within 48 hours before the next scheduled exchange transfusion
Working Memory - WAIS-IV Digit Span Subtest
The Digit Span subtest from the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV), assesses working memory capacity. Scores range from 0 to 16, with higher scores reflecting better performance.
Measured: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Sep 2025
- Study start3 Dec 2025 (estimated)
- Primary completion2 Nov 2027 (estimated)
- Study completion2 Nov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DrepanocytosisStudies 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
- Other
- Enrolment
- 85 participants (estimated)
- Target duration
- 6 Weeks
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier St Anne
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- HUGO BISMUTH, DOCTOR, Principal investigator, Hôpital Sainte-AnneDavid CLAVET, PROFESSOR, Study chair, Hôpital Sainte-Anne
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07168447
- Sponsor's protocol ID
- D24-P021
- Other IDs
- IDRCB : 2024-A02851-46
- Acronym
- DREPA-COG
- Status last verified
- Sep 2025
- First submitted
- 18 Aug 2025
- Last updated
- 11 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Exchange Transfusions on Cognitive Efficiency in Patients With Sickle Cell Disease
- ClinicalTrials.gov ID
- NCT07168447
- Acronym / sponsor ID
- DREPA-COG / D24-P021
- Conditions
- Drepanocytosis, Chronic Neurological Deficiency
- Keywords
- Sickle cell disease, cognitive function, neuropsychological assessment, transfusion exchange, non-interventional study, executive function, SDMT, T-MoCA, fatigue, anxiety, depression
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 85 participants (estimated)
- Lead sponsor
- Centre Hospitalier St AnneUniversity, hospital or other
- Study start
- 3 Dec 2025 (estimated)
- Primary completion
- 2 Nov 2027 (estimated)
- Study completion
- 2 Nov 2027 (estimated)
- First posted
- 11 Sep 2025 (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.
DREPA-COG is an observational study evaluating the effect of exchange transfusions on cognitive function in adults with severe sickle cell disease (SS or Sβ0). Information processing speed is assessed at three time points during the transfusion cycle using the Symbol Digit Modalities Test (SDMT) and additional validated neuropsychological measures. This minimal-risk, fully remote study aims to identify processing speed as a reproducible marker for clinical monitoring and future therapeutic trials.
Detailed description
DREPA-COG is a non-interventional, multicenter observational study investigating the effect of exchange transfusions on cognitive performance in adults with severe sickle cell disease (SS or Sβ0). Cognitive complications, including slowed information processing and executive dysfunction, are frequent and disabling in this population. Exchange transfusion, a standard therapy replacing sickled red blood cells with donor cells, may positively influence cognition, but systematic evidence is lacking.
The study evaluates information processing speed as a potential neurological marker across the transfusion cycle. Participants complete three brief neuropsychological assessments remotely by videoconference: before the transfusion, one week after, and prior to the next transfusion. The Symbol Digit Modalities Test (SDMT) is the primary measure, complemented by validated assessments of global cognition, attention, memory, fatigue, mood, and pain.
Primary analysis will use mixed-effects models to assess changes in processing speed over time, adjusting for demographic and clinical covariates. This minimal-risk, fully remote study requires no additional hospital visits and aims to establish processing speed as a reproducible and clinically relevant outcome measure in sickle cell disease.
Study design
- Observational model
- Cohort
- Time perspective
- Other
- Target follow-up
- 6 Weeks
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study population consists of adults aged 18 years or older with severe sickle cell disease (SS or Sβ0) who are enrolled in a regular monthly transfusion exchange program. Participants must not be institutionalized, must have no known dementia or severe aphasia, and must be able to communicate in French. They must also be affiliated with a social security system. Excluded are individuals with severe comorbidities that could interfere with short-term follow-up, those with known psychiatric disorders, participants in other ongoing clinical studies with exclusion periods, individuals lacking adequate computer equipment for remote assessments, and vulnerable patients under legal protection such as guardianship or curatorship. This population allows evaluation of cognitive processing speed and other neuropsychological outcomes in a controlled, transfusion-managed cohort of adult sickle cell patients.
Key inclusion criteria (6 listed)
- Adults (≥18 years) with severe sickle cell disease (SS or Sβ0).
- Enrolled in a regular monthly transfusion exchange program.
- Not institutionalized.
- No known dementia.
- No severe aphasia.
Key exclusion criteria (6 listed)
- Insufficient mastery of spoken French.
- Severe comorbidities preventing short-term follow-up.
- Known psychiatric disorders.
- Participation in another clinical study with ongoing exclusion periods.
- Lack of adequate computer equipment (minimum 11-inch screen and internet connection).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Information Processing Speed
Time frame: 48 hours before the transfusion exchange
Primary outcome measure: Information processing speed, assessed using the oral version of the Symbol Digit Modality Test (SDMT), as a marker of cerebral involvement in adult patients with sickle cell disease.
Information Processing Speed
Time frame: 7 to 9 days after the transfusion exchange
Primary outcome measure: Information processing speed, assessed using the oral version of the Symbol Digit Modality Test (SDMT), as a marker of cerebral involvement in adult patients with sickle cell disease.
Information Processing Speed
Time frame: within 48 hours before the next scheduled transfusion exchange
Primary outcome measure: Information processing speed, assessed using the oral version of the Symbol Digit Modality Test (SDMT), as a marker of cerebral involvement in adult patients with sickle cell disease.
6 secondary outcomes
Global Cognitive Function - Montreal Cognitive Assessment (Telephone version, T-MoCA)
Time frame: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Fatigue Severity Score (FSS)
Time frame: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Anxiety and Depression Symptoms (Hospital Anxiety and Depression Scale, HADS
Time frame: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Pain Intensity (Numeric Rating Scale, NRS)
Time frame: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
Change in Information Processing Speed Measured by the Symbol Digit Modalities Test (SDMT)
Time frame: Within 48 hours before exchange transfusion 7-9 days after exchange transfusion Within 48 hours before the next scheduled exchange transfusion
Working Memory - WAIS-IV Digit Span Subtest
Time frame: Time Point 1 (Baseline): within 48 hours before the scheduled exchange transfusion. Time Point 2 (Post-transfusion): 7 to 9 days after the exchange transfusion. Time Point 3 (End of cycle): within 48 hours before the next scheduled exchange transfusion
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 Sep 2025.
- Individual participant dataSharing planned: Undecided
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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.
HUGO BISMUTH, DOCTOR principal investigator
Hôpital Sainte-Anne
David CLAVET, PROFESSOR study chair
Hôpital Sainte-Anne
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Drepanocytosis and Chronic Neurological Deficiency, run by Centre Hospitalier St Anne at 6 sites in France.
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 6 inclusion and 6 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: opening soon, as of the sponsor's last update on 11 Sep 2025. 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 France. 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?
Contact OUIZA MANSEUR, PROJECT MANAGER (01 45 65 84 86 ext. +33, ouiza.manseur@ghu-paris.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Information Processing Speed (time frame: 48 hours before the transfusion exchange). The study lists 3 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 Sep 2025.