Chronic Neurological Deficiency, Drepanocytosis
Conditions
Keywords
Sickle cell disease, cognitive function, neuropsychological assessment, transfusion exchange, non-interventional study, executive function, SDMT, T-MoCA, fatigue, anxiety, depression
Brief 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 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.
Interventions
None listed
Sponsors
Centre Hospitalier St Anne
Study design
Observational model
COHORT
Time perspective
OTHER
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 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.
Exclusion criteria
* 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).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Information Processing Speed | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fatigue Severity Score (FSS) | 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 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. |
| Anxiety and Depression Symptoms (Hospital Anxiety and Depression Scale, HADS | 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 | 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. |
| Global Cognitive Function - Montreal Cognitive Assessment (Telephone version, T-MoCA) | 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 | 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. |
| Change in Information Processing Speed Measured by the Symbol Digit Modalities Test (SDMT) | Within 48 hours before exchange transfusion 7-9 days after exchange transfusion Within 48 hours before the next scheduled exchange transfusion | 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. |
| Working Memory - WAIS-IV Digit Span Subtest | 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 | 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. |
| Pain Intensity (Numeric Rating Scale, NRS) | 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 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. |
Countries
France
Contacts
Primary ContactOUIZA MANSEUR, PROJECT MANAGER
Backup ContactKhaoussou SYLLA, MEDICAL COORDINATOR
Outcome results
None listed