Clinical trial NCT06998381: Ethnic Specificities of S100B Protein Blood Level in Guadeloupe: Cross-sectional Study in Healthy Subjects
Official title: Ethnic Specificities of S100B Protein Blood Level in Guadeloupe: Cross-sectional Study in Healthy Subjects
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: s100b
Keywords: S100B Protein
Lead sponsor: Centre Hospitalier Universitaire de la Guadeloupe
Sponsor class: OTHER
First posted: 2025-05-31
Enrollment: 200
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: OTHER
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Hospital staff of the University Hospital of Guadeloupe or the Basse-Terre Hospital

Brief summary: Numerous studies have demonstrated the significant contribution of S100B blood level measurement in the management of minor to moderate traumatic brain injuries, notably by reducing the number of cranial computed tomography (CT) scans by at least one-third. However, physiological blood concentrations of the S100B protein may be higher in individuals with a Black phenotype compared to those with Asian or, in particular, Caucasian phenotypes. Assessing S100B protein levels in healthy individuals will help confirm the variability of its physiological concentration according to skin phenotype.

Detailed description: Thanks to its excellent negative predictive value, the S100B protein has been defined as a reliable alternative to computed tomography (CT) in the management of traumatic brain injury (TBI). Validated by scientific societies in 2014, the use of this biomarker could reduce the number of cerebral CT scans by nearly one-third in cases of minor TBI.

However, implementation of this blood test in routine clinical practice may present challenges. The extrapolation of findings from S100B studies to the context of Guadeloupe remains uncertain. The commonly accepted threshold of 0.1 μg/L for S100B protein, used to determine the need for CT imaging, has been established based on existing literature. Nevertheless, the study by Abdesselam (Clinical Chemistry 49, No. 5, 2003) suggests that S100B concentrations may vary by ethnic background: higher levels have been observed in individuals of Black phenotype (0.14 ± 0.08 μg/L) compared to those of Asian (0.11 ± 0.08 μg/L) and Caucasian (0.07 ± 0.03 μg/L) phenotypes.

A closer analysis of Abdesselam's data reveals that approximately three-quarters of individuals with a Black phenotype may present physiological S100B levels exceeding 0.1 μg/L. Given that the majority of Guadeloupe's population is of Black phenotype, applying the 0.1 μg/L threshold for CT scan decision-making may lack accuracy for this population. Nonetheless, Abdesselam's study involved a limited sample size (46 individuals of Black ethnicity) and showed high interindividual variability in S100B levels. Further validation is therefore required in Guadeloupe and, more broadly, in Caribbean populations.

The planned study will enroll hospital staff who meet predefined eligibility criteria. Prior to inclusion, eligible individuals will receive an information leaflet and consent form, both explained by a physician or a clinical research nurse. Upon obtaining signed informed consent, each subject will complete an anonymous questionnaire detailing ethnic background, age, sex, and weight. A blood sample will then be collected and sent to the biochemistry laboratory at the University Hospital of Guadeloupe for S100B protein analysis.

Eligibility criteria: Inclusion Criteria :

* Hospital staff of the University Hospital of Guadeloupe or the Hospital of Basse-Terre
* Age between 18 and 65 years
* Individuals willing to specify their ethnic origin and skin phototype
* Individuals affiliated with or beneficiaries of a social security scheme
* Informed individuals who have given their voluntary, informed, and written consent

Exclusion Criteria :

* Individuals on anticoagulant therapy
* Individuals with a personal history of neurological disease
* Individuals with a personal history of melanoma
* Refusal to participate
* Individuals under guardianship, curatorship, or legal protection

Primary outcomes:
measure: S100B and ethnicity
timeFrame: baseline
Secondary outcomes:
measure: S100B and phototypes
timeFrame: baseline
Other outcomes:
Locations:
city: Basse-Terre
country: Guadeloupe
facility: CH de la Basse-Terre
city: Pointe-à-Pitre
country: Guadeloupe
facility: Chu de La Guadeloupe
Study officials:
affiliation: CHU de la Guadeloupe
name: Delphine Delta, MD
role: PRINCIPAL_INVESTIGATOR
References: