de Rivero Vaccari, Juan Pablo

Emerging evidence suggests that systemic physiological factors may influence plasma biomarker concentrations of Alzheimer’s disease (AD) and related neurodegenerative processes, potentially affecting their specificity for central nervous system pathology. This study examined the relationship of demographic factors and medical comorbidities with plasma biomarkers of AD and neurodegeneration in a community-dwelling cohort of Black/African American (B/AA) older adults (N = 141). Participants underwent plasma assessment of phosphorylated tau at threonine 217 (p-Tau217), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL). Results showed associations between plasma p-Tau217 and amyloid PET positivity, and significant intercorrelations among p-Tau217, GFAP, and NfL. Stepwise regression models incorporated demographics, amyloid PET status, and laboratory measures of renal, metabolic, and lipid function as predictors for each biomarker. p-Tau217 was primarily predicted by amyloid PET and renal function; GFAP by age and sex; and NfL by renal function, age, and sex. Findings indicate plasma biomarker concentrations in B/AA older adults reflect both central AD-related pathology and systemic physiological factors, particularly renal function, and demographic influences. Results underscore the importance of accounting for comorbid medical conditions and demographic characteristics when interpreting blood-based biomarkers and highlight the need for comprehensive medical phenotyping to improve diagnostic specificity and clinical utility.

Traumatic brain injury (TBI) is one of the leading causes of death and neurological disability worldwide. The search for biomarkers that indicate TBI severity and prognosis with greater accuracy is ongoing. This study aimed to evaluate the significance of several neuroinflammatory cytokines and chemokines, assessing their potential as biomarkers in pediatric TBI (pTBI). This was an exploratory analysis of inflammatory cytokines and chemokines measured in a subset of 26 children aged 0–18 years with TBI and 21 controls. TBI severity was determined by GCS. The functional outcome was measured via the GOS-E score at 6 weeks and 3, 6, 9, and 12 months post-injury. Serum samples were analyzed for ICAM-1, VCAM-1, SAA, CRP, IFN-g, IL-10, IL-12p70, IL-13, IL-1b, IL-2, IL-4, IL-6, IL-8, TNF-a, TNF-b, eotaxin, eotaxin-3, IP-10, MCP-1, MCP-4, MDC, MIP-1a, MIP-1b and TARC. Levels of IL-6, IL-10, IL-13, IL-16, MDC, and GM-CSF were increased, and IFN-γ, IL-5, IL-8, and eotaxin-3 were decreased at enrollment when compared with controls. Elevated IL-6 and IL-10 at enrollment were associated with severe TBI (AUC of 1, p = 0.0002 and p = <0.0001, respectively). IL-6, IL-10, IL-16, and TNF-β at enrollment and IL-5 at 24 h were elevated in children with unfavorable outcomes, with an AUC > 0.8, suggesting biomarker potential. Our data indicate that several cytokines and chemokines measured after TBI may aid in the assessment of pTBI severity and prognosis. IL-6, IL-10, and IL-16 may show potential as biomarkers for pTBI severity and outcomes.

Traumatic brain injury (TBI) remains a major cause of morbidity and death among the pediatric population. Timely diagnosis, however, remains a complex task because of the lack of standardized methods that permit its accurate identification. The aim of this study was to determine whether serum levels of brain injury biomarkers can be used as a diagnostic and prognostic tool in this pathology. This prospective, observational study collected and analyzed the serum concentration of neuronal injury biomarkers at enrollment, 24h and 48h post-injury, in 34 children ages 0–18 with pTBI and 19 healthy controls (HC). Biomarkers included glial fibrillary acidic protein (GFAP), neurofilament protein L (NfL), ubiquitin-C-terminal hydrolase (UCH-L1), S-100B, tau and tau phosphorylated at threonine 181 (p-tau181). Subjects were stratified by admission Glasgow Coma Scale score into two categories: a combined mild/moderate (GCS 9–15) and severe (GCS 3–8). Glasgow Outcome Scale-Extended (GOS-E) Peds was dichotomized into favorable (≤4) and unfavorable (≥5) and outcomes. Data were analyzed utilizing Prism 9 and R statistical software. The findings were as follows: 15 patients were stratified as severe TBI and 19 as mild/moderate per GCS. All biomarkers measured at enrollment were elevated compared with HC. Serum levels for all biomarkers were significantly higher in the severe TBI group compared with HC at 0, 24, and 48h. The GFAP, tau S100B, and p-tau181 had the ability to differentiate TBI severity in the mild/moderate group when measured at 0h post-injury. Tau serum levels were increased in the mild/moderate group at 24h. In addition, NfL and p-tau181 showed increased serum levels at 48h in the aforementioned GCS category. Individual biomarker performance on predicting unfavorable outcomes was measured at 0, 24, and 48h across different GOS-E Peds time points, which was significant for p-tau181 at 0h at all time points, UCH-L1 at 0h at 6–9 months and 12 months, GFAP at 48h at 12 months, NfL at 0h at 12 months, tau at 0h at 12 months and S100B at 0h at 12 months. We concluded that TBI leads to increased serum neuronal injury biomarkers during the first 0–48h post-injury. A biomarker panel measuring these proteins could aid in the early diagnosis of mild to moderate pTBI and may predict neurological outcomes across the injury spectrum.