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Brain, Behavior, & Immunity - Health

○ Elsevier BV

Preprints posted in the last 7 days, ranked by how well they match Brain, Behavior, & Immunity - Health's content profile, based on 28 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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T-cell dysregulation is implicated in the encephalopathy of prematurity

Smikle-Bernard, R.; Blesa Cabez, M.; Vaher, K.; Amir, R.; Mckinnon, K.; Murphy, L.; Thrippleton, M. J.; Quigley, A. J.; Bastin, M. E.; Reynolds, R. M.; Whalley, H. C.; Marioni, R. E.; Cox, S. R.; Boardman, J. P.

2026-10-16 neurology 10.64898/2026.10.15.26365621 medRxiv
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Preterm birth is strongly linked to systemic inflammation and encephalopathy of prematurity, which underlies subsequent cognitive impairment. T-cell immunity contributes to brain-immune crosstalk across the life course but its role in the pathogenesis of encephalopathy of prematurity is unknown. Protein epigenetic scores are DNA methylation (DNAm)-based proxies of circulating proteins. We tested the hypothesis that T-cell dysregulation has a specific role in child neurodevelopment following preterm birth. Multimodal data were collected from 144 preterm infants (median gestational age at birth 29+5 weeks [range 23+3 to 32+6]) recruited to a prospective cohort study: saliva DNAm for protein epigenetic score derivation and brain MRI, both at term-equivalent age, and the Mullen Scales of Early Learning Composite score at 5 years from a subset. We investigated associations of the epigenetic scores for cytotoxic and regulatory T cell-associated molecule (DNAm CRTAM) and C-reactive protein (DNAm CRP; a non-specific marker of inflammation) with MRI metrics of encephalopathy of prematurity: global and regional brain volumes, and general factors of diffusion tensor imaging and neurite orientation dispersion and density imaging metrics averaged across 42 white matter tracts. We tested whether DNAm CRTAM explains more variance than DNAm CRP in MRI metrics of the encephalopathy of prematurity and cognitive scores in childhood. Higher neonatal DNAm CRTAM was associated with lower general factor of fractional anisotropy ({beta} = -0.252, q = 0.011) and higher general factors of radial diffusivity ({beta} = 0.215, q = 0.039), mean diffusivity ({beta} = 0.198, q = 0.047) and orientation dispersion index ({beta} = 0.201, q = 0.048), independent of inflammatory morbidities and other biological covariates after false discovery rate correction. DNAm CRTAM explained more variance than DNAm CRP (maximum incremental R2 = 4.2% vs 1.5%) in diffusion MRI metrics. Higher neonatal DNAm CRTAM was associated with lower cognitive scores at 5 years, independent of DNAm CRP and other covariates ({beta} = -0.332, P = 0.008), and explained more variance in cognitive scores than DNAm CRP (incremental R2 = 9.4% vs 1.2%). An epigenetic proxy of CRTAM in preterm infants is associated with both encephalopathy of prematurity in the neonatal period and lower cognitive performance at 5 years, explaining greater incremental variance than a non-specific marker of inflammation. The data implicate T-cell dysregulation in the pathophysiology of atypical neurodevelopment following preterm birth.

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The Th17/IL-17 Axis and Systemic Inflammatory Biomarkers in Sepsis-Associated Encephalopathy and Delirium: A Systematic Review and Meta-Analysis

Chaves Filho, A. M.; Nascimento, E. F.; Goncalves, L. D. C.; Dias Filho, F. J.; Oliveira, T. Q.; Macedo, D. S.; Dal-Pizzol, F.; de Moraes, M. E. A.; Barichello, T.

2026-10-21 intensive care and critical care medicine 10.64898/2026.10.16.26365073 medRxiv
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OBJECTIVE: Sepsis-associated encephalopathy (SAE) and sepsis-associated delirium (SAD) lack confirmatory laboratory tests or biomarkers. We evaluated whether the Th17/interleukin (IL)-17 axis or neuroglial-injury biomarkers reflect acute brain dysfunction beyond systemic inflammation and whether biomarker profiles differ between these phenotypes. DATA SOURCES: EMBASE, MEDLINE/PubMed, and the Cochrane Library from inception to August 1, 2026, supplemented by backward and forward citation searching, following PRISMA 2020. STUDY SELECTION: Observational studies of adults with sepsis classified by SAE or SAD status and reporting circulating biomarker concentrations by neurological group or biomarker-outcome associations. Eighteen studies (2,388 participants; 1,863 with sepsis) were included. DATA EXTRACTION: Two reviewers independently extracted study, phenotype, assay, and outcome data. Risk of bias was assessed with the Newcastle-Ottawa Scale and certainty with GRADE. DATA SYNTHESIS: Random-effects models pooled standardized mean differences (SMDs) separately against non-septic and septic controls and odds ratios (ORs) for biomarker-outcome associations. IL-6 was the only mediator elevated in both comparative frameworks and associated with outcomes (non-septic controls: SMD, 0.54 [0.25-0.82]; septic controls: SMD, 1.05 [0.51-1.59]; OR, 1.85 [1.50-2.29]). S100B, neuron-specific enolase, IL-10, tumor necrosis factor; and interferon-gamma; were elevated versus septic controls, whereas IL-17 was modestly elevated only versus non-septic controls (SMD, 0.37 [0.01-0.73]). The IL-6 septic-control effect was concentrated in SAE (p<0.0001) and remained robust in leave-one-out and risk-of-bias sensitivity analyses. Certainty was low to very low, and all 14 computable prediction intervals included the null. CONCLUSIONS: IL-6 emerges as the leading circulating candidate biomarker of sepsis-associated brain dysfunction, while S100B and NSE capture neuroglial injury beyond sepsis. Current evidence does not establish a discriminating role for the Th17 axis. Future studies require standardized neurological phenotyping and appropriately matched septic controls to establish diagnostic value.

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Fibromyalgia, Chronic Fatigue Syndrome, and Multiple Sclerosis are associated with lower translocator protein binding affinity genotypes

Jones, C. L.; Younger, J. W.

2026-10-21 neurology 10.64898/2026.10.19.26365953 medRxiv
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Introduction: Neuroinflammation is a known pathophysiologic mechanism in multiple sclerosis and a proposed mechanism in fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Positron Emission Tomography (PET) imaging of the translocator protein (TSPO) has been widely used to measure neuroinflammation, though second-generation ligands are highly sensitive to a single nucleotide polymorphism, rs6971, resulting in high, mixed, and low affinity binders. It is unknown whether this polymorphism is associated with neuroinflammatory disorders. Materials and Methods: Eighty-six total participant genotypes for TSPO binding affinity were identified through Sanger sequencing (30 fibromyalgia, 21 ME/CFS, 11 multiple sclerosis, and 24 healthy controls). Associations between patient group and genotype were assessed with Fishers Exact test. Associations between genotype and symptom severity from self-report questionnaires were assessed with Kruskal-Wallis tests. Results: In the present study individuals with fibromyalgia, (ME/CFS), or multiple sclerosis were more likely to have a mixed- or low-affinity genotypes compared to healthy controls. Presence of the low or mixed genotypes were also associated with greater self-reported fatigue severity and depressive symptoms. Discussion: These findings should be confirmed in larger samples but suggest functional consequences of rs6971 polymorphism that may be related to the pathophysiology of pain and fatigue illnesses.

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Concussion, Attention, and Mental Health: A Brain Network Study in Youth (CAMBY) - Study Protocol

Scratch, S.; Gill, P. K.; Hickling, A.; Irvin, A.; Zamyadi, R.; Parimoo, S.; Johnston, P. R.; Davis, A. L.; Ibrahim, G. M.; Dunkley, B. T.; Wheeler, A. L.

2026-10-20 neurology 10.64898/2026.10.14.26365111 medRxiv
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BACKGROUND: One in three adolescents with a concussion history report experiencing long-lasting somatic, sleep, emotional, and/or cognitive disturbances (persisting symptoms after concussion (PSaC)). Cognitive difficulties, such as attentional problems, are common symptoms and can interfere with ongoing development. Clinically, psychiatric symptoms also present in youth with PSaC. A concussion causes diffuse functional and microstructural alterations to neural networks. To develop targeted treatments for PSaC (e.g., neurostimulation), we need to understand how and where structural alterations and neural dysfunction intersect to cause long-lasting symptoms. OBJECTIVES: 1) Identify functional and microstructural properties in intrinsic connectivity networks, as well as neuropsychological outcomes, that differentiate adolescents with concussion with PSaC from those who do not have PSaC. 2) Determine whether neural activity within intrinsic connectivity networks mediates the relationship between network microstructure and specific neuropsychological features in adolescents with concussion. METHODS: CAMBY is a prospective study of adolescents aged 12 to 18 years with a history of concussion. Participants are allocated based on recovery status (PSaC vs. No-PSaC (recovered controls)). Advanced structural (magnetic resonance imaging; MRI) and functional (magnetoencephalography; MEG) neuroimaging and neuropsychological measures will be collected one month or more after concussion. Microstructural and functional features will be computed within intrinsic connectivity networks, then compared between PSaC and recovered control groups and related to symptom domains and neuropsychological profiles. IMPACT: This will be the first study to integrate MRI, MEG, and neuropsychology in adolescents with PSaC to identify disrupted networks underlying PSaC. This observational study is a necessary step towards future clinical trials that accurately target promising therapeutic neurostimulation protocols.

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Maternal body mass index in early pregnancy and offspring risk of multiple sclerosis: A population-based cohort study

Xu, H.; Razaz, N.; Remaeus, K.; Lee, J.; Fink, K.; McKay, K. A.

2026-10-16 neurology 10.64898/2026.10.15.26365617 medRxiv
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Objective To examine whether prospectively recorded maternal BMI in early pregnancy is associated with offspring multiple sclerosis (MS) risk, including childhood-onset and adult-onset MS. Design Nationwide population-based cohort study. Setting Swedish national health and demographic registers. Participants 1,524,863 singleton children born in Sweden from 1992 to 2007 and followed through 2025. Exposures Maternal BMI recorded at the first antenatal visit, categorised as underweight (<18.5), normal weight (18.5-24.9), overweight (25.0-29.9), and obesity ([&ge;]30.0), and also modelled continuously. Main outcome measures MS in offspring, identified as at least three ICD-10 G35 codes recorded on separate dates. Cox models estimated adjusted hazard ratios (HR) and 95% confidence intervals (CI) adjusting for confounders. Results During follow-up, 1539 offspring (0.1%) were diagnosed with MS at a median age of 24 years (interquartile range, 20-27 years). MS incidence rates by maternal BMI category were 0.37 per 10,000 person-years for both underweight, and normal weight, 0.42 for overweight, and 0.45 for obesity. Compared with normal weight women, maternal overweight and obesity were associated with higher hazards of offspring MS, with adjusted HRs of 1.20 (95% CI, 1.05 to 1.37) and 1.35 (95% CI, 1.11 to 1.64), respectively. Onset-specific analyses showed similar findings for adult-onset MS and less precise but directionally consistent estimates for paediatric-onset MS. Each 1-unit increase in maternal BMI was associated with a 3%, 4%, and 3% higher hazard of overall, paediatric-onset, and adult-onset offspring MS, respectively. Conclusions In this population-based cohort study, higher maternal BMI were associated with an increased rate of MS in offspring. The findings provide large-scale prospective evidence that maternal adiposity may be related to offspring MS risk and support further investigation of the prenatal metabolic environment in the early-life origins of MS.

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Prognostic significance of the C-reactive protein-albumin-lymphocyte (CALLY) index in primary lung malignancies: a systematic review and meta-analysis with GRADE assessment

Shamohammadi, M.; Yarahmadi, D.; Naseri Rad, F.; Patel, I.; Yarahmadi, M.; Rashidi, A.; Yarahmadi, A.; Kordestani Moghadam, P.; Naghavi, N.

2026-10-20 oncology 10.64898/2026.10.18.26365819 medRxiv
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Background: The C-reactive protein-albumin-lymphocyte (CALLY) index integrates systemic inflammation, nutritional status, and immune function. We evaluated its association with survival in primary lung malignancies. Methods: Embase, PubMed, Scopus, and Web of Science were searched from inception to 18 September 2026. Risk of bias was assessed using the Quality In Prognosis Studies tool. Hazard ratios (HRs) were synthesized using random-effects models with restricted maximum likelihood estimation and Hartung-Knapp adjustment. Sensitivity analyses, subgroup analyses, and meta-regression examined robustness and heterogeneity. Results: Eleven studies contributed 13 cohorts to the overall survival (OS) analysis and 8 cohorts from seven studies to a combined recurrence/progression-free survival (RFS/PFS) analysis. Lower CALLY was associated with poorer OS (HR 1.78, 95% CI 1.49-2.12; I2=71.6%) and poorer RFS/PFS (HR 1.60, 95% CI 1.40-1.84; I2=0%). Associations persisted in leave-one-out analyses. No statistically significant subgroup differences were detected. Funnel-plot asymmetry suggested small-study effects for OS and RFS/PFS. Seven studies had moderate and four had high overall risk of bias. The certainty of evidence was rated as low for both OS and RFS/PFS, primarily due to risk of bias, heterogeneity, and endpoint indirectness. Conclusion: Lower CALLY was associated with adverse survival outcomes in the current synthesis. Methodological limitations and variation in biomarker measurement and endpoint definitions restrict interpretation. Prospective validation using standardized measurements and clinically coherent outcomes is needed to establish incremental prognostic value and clinical utility. Keywords: CALLY index; lung cancer; prognosis; overall survival; systematic review; meta-analysis

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Understanding Psychological Health in Adults with Irritable Bowel Syndrome: A Cross-Sectional Study Using the All of Us Research Program

Wu, W.; Li, A.; Chen, J.; You, E.; Liu, P.; Rodriguez, L.; Chen, M.-H.; Cong, X.

2026-10-21 gastroenterology 10.64898/2026.10.20.26365988 medRxiv
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Background: Psychological health is an important aspect of health and well-being among adults with irritable bowel syndrome, yet the interrelationships among individual vulnerabilities, social experiences, perceived stress, and psychological health outcomes remain poorly understood. Objective: To characterize psychological health and examine direct and indirect associations of childhood adversity and adult attention-deficit/hyperactivity disorder-related symptoms within an adapted Stress Process Model. Design: Cross-sectional secondary analysis. Setting: The United States All of Us Research Program. Participants: 2,417 adults with electronic health record-documented irritable bowel syndrome and complete data on the primary analysis variables and covariates. Methods: Separate structural equation models examined childhood adversity and adult attention-deficit/hyperactivity disorder-related symptoms in relation to perceived stress, anxiety and depressive symptoms, and positive psychological well-being, with loneliness and perceived social support as psychosocial pathways. Models adjusted for sociodemographic and social-context factors. Results: The median age was 54.39 years; 80.7% were female and 84.4% were White. Moderate-to-high perceived stress was reported by 56.2%, at least moderate anxiety symptoms by 21.0%, and at least moderate depressive symptoms by 24.3%. Higher ACE-8 scores were associated with greater perceived stress, anxiety symptoms, and depressive symptoms and lower psychological well-being ({beta} = 0.063, 0.089, 0.116, and -0.100, respectively); corresponding associations for higher ASRS-6 scores were {beta} = 0.299, 0.355, 0.390, and -0.260. Loneliness-specific indirect associations were positive for perceived stress, anxiety, and depressive symptoms (ACE-8: {beta} = 0.023-0.034; ASRS-6: {beta} = 0.043-0.075) and negative for psychological well-being (ACE-8: {beta} = -0.039; ASRS-6: {beta} = -0.089; all p < .001). Social support-specific indirect associations were not significant in the ACE-8 model and were small and significant only for anxiety and depression in the ASRS-6 model ({beta} = 0.003-0.004). Conclusions: Psychological health among adults with irritable bowel syndrome was associated with interconnected individual and social factors within an adapted Stress Process Model. Childhood adversity and adult attention-deficit/hyperactivity disorder-related symptoms showed direct and indirect associations with psychological health, with loneliness emerging as the most consistent social factor. These findings support prospective investigation of individual vulnerabilities and social experiences in psychological health. The cross-sectional design does not establish temporal ordering or causal mediation.

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Peripheral Biomarkers and Determinants of Survival for Patients with Melanoma Brain Metastasis Treated with Immune Checkpoint Blockade

Hassan, J.; Little, M.; Farkas, A.; Mackay, S.; Coupe, N.; Middleton, M.; Payne, M. J.; Fairfax, B.

2026-10-21 oncology 10.64898/2026.10.19.26365947 medRxiv
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Background Immune checkpoint blockade (ICB) has become the standard of treatment for metastatic melanoma (MM). However, patients with melanoma brain metastases (MBM) are often excluded from clinical trials. Here we analyse patients within the real-world OxCITE cohort receiving ICB treatment for metastatic melanoma, with a focus on MBM, aiming to discern outcomes, prognostic factors and peripheral biomarkers. Methods Patients eligible for ICB treatment were recruited prospectively. Demographic, clinical and radiological data were collected from electronic patient records. Plasma samples were collected prior to the first cycle of treatment for plasma proteomic analysis. Results 307 patients were included, 81 of whom had MBM on commencing ICB. No difference in overall survival between patients with and without brain metastases was noted on multivariable analysis (HR=1.1, 95% CI 0.73-1.6, p=0.68), whereas hepatic metastases were associated with increased risk of death (HR 1.7, 95% CI 1.2-2.4, p=0.0019). Within the MBM group, steroid treatment (HR=2.5, 95% CI 1.3-5.0, p=0.006) was associated with poor OS, whilst treatment with single agent ICB (HR=1.9, 95% CI 0.86-3.9, p=0.11), symptomatic first presentation of MBM (HR=1.5, 95% CI 0.76-2.8, p=0.25) and anti-seizure drug treatment (HR=1.74, 95% CI 0.89-3.4, p=0.10) were not. Amongst all patients carriage of a BRAF mutation was associated with increased risk of MBM (OR 2.49, 95% CI 1.4-4.4, p=0.0007), and increased propensity to new brain metastases on ICB treatment (OR 2.5, 95% CI 1.1-5.9, p=0.036). Analysis of blood and plasma samples demonstrated that patients with MBM have altered haematological profiles, with raised NLR and increased plasma glial fibrillary acidic protein levels, reinforcing the distinct systemic features of MBM. Conclusions In this real-world cohort of patients receiving ICB for metastatic melanoma, the presence of MBM did not associate with worse OS. Conversely, baseline corticosteroid use was adversely prognostic. Intriguingly, plasma GFAP was significantly elevated in patients with MBM and correlated with the burden of intracranial disease, highlighting a potential role for GFAP as a candidate biomarker for MBM in high-risk surveillance. Our observations indicate the adversely prognostic weight historically attached to M1d disease is no longer applicable in the ICB era.

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Change in gut microbiome precedes symptomatic Alzheimer's disease and is correlated with amyloid-beta accumulation in the brain

Shoubridge, A. P.; Manning, S. K.; Tan, S.; Kidson, S.; Richard, A.; Trinder, J.; Miller, S.; Laver, K.; Rahja, M.; Robertson, J.; Crotty, M.; Taylor, S. L.; Rogers, G. B.

2026-10-19 neurology 10.64898/2026.10.15.26365677 medRxiv
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INTRODUCTION: Alzheimer's disease (AD) begins with cerebral amyloid-beta (A{beta}) deposition decades before clinical symptoms. While the microbiota-gut-brain axis has been implicated in AD, its role in this preclinical phase remains unclear. We examined potential links between gut microbiome features and presymptomatic cerebral A{beta} burden. METHODS: Asymptomatic individuals (n=101, median age 70.0 years, 53% female) underwent cognitive assessment, cerebral A{beta} quantification, and stool metagenomic sequencing. Associations between microbial characteristics and A{beta} levels were performed using multivariable-adjusted ordinal logistic regression. RESULTS: Gut microbiota composition varied with A{beta} levels (p(perm)=0.03, R2=0.014). Higher A{beta} was associated with increased Alistipes communis, and decreased Anaerotignum faecicola and Eubacterium rectale, abundance (q<0.001). A{beta}-associated microbiome traits corresponded to lower biosynthetic capacity for {gamma}-aminobutyric acid, and systemic regulators of immunity and autophagy (q<0.01). DISCUSSION: Early A{beta} accumulation is associated with distinct gut microbial signatures and reduced neuroactive metabolic potential, identifying targets for potential preclinical AD intervention.

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From Gut to Brain: A Longitudinal Assessment of Intestinal Permeability and Immune Activation Markers in Early-Stage Schizophrenia Spectrum Disorders

Jakob, L.; Mahayri, T. M.; Koutrouli, I. R. A.; Kekrtova, K.; Novakova, D.; Totkova, T.; Spaniel, F.

2026-10-19 psychiatry and clinical psychology 10.64898/2026.10.16.26364494 medRxiv
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Schizophrenia spectrum disorders (SSD) have been linked to immune dysregulation and altered intestinal barrier function, although findings across studies remain inconsistent. The present study investigated circulating markers of intestinal permeability and immune activation in individuals with early-stage SSD and healthy controls and examined their associations with clinical outcomes. Serum concentrations of intestinal fatty acid-binding protein (iFABP), zonulin, soluble CD14 (sCD14), bactericidal/permeability-increasing protein (BPI), and lipopolysaccharide-binding protein (LBP) were measured in 36 patients with SSD at baseline and one-year follow-up and in 36 matched healthy controls. Linear mixed-effects models adjusted for age, sex, and body mass index (BMI) were used to evaluate group differences and longitudinal changes. No biomarker differences between patients and controls, and no longitudinal changes within patients, remained statistically significant after correction for multiple testing. Similarly, biomarker concentrations were not associated with symptom severity, global functioning, or neutrophil-to-lymphocyte ratio (NLR). Exploratory analyses identified a robust positive association between BMI and zonulin concentrations and additional associations among iFABP, LBP, and sCD14. Exploratory mixed-effects models identified a negative non-significant association between iFABP and sCD14 after adjustment for age, sex, and BMI. Overall, the findings do not support a generalized alteration of gut permeability or immune activation markers in SSD. Instead, they suggest that variation in gut-related biomarkers may be more strongly influenced by metabolic and individual factors than by diagnosis or current symptom severity.

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Change in the neutrophil-to-lymphocyte ratio after a 3-day orbital flight: A preregistered secondary analysis of NASA open data from the Inspiration4 civilian crew

GODINEZ VAZQUEZ, V. J.

2026-10-19 occupational and environmental health 10.64898/2026.10.16.26365757 medRxiv
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Background: Commercial spaceflight now carries civilians on short missions, yet their stress-axis physiology is poorly described. Earlier shuttle data suggest that sympathetic responses predominate after short flights and glucocorticoid responses after long ones. The neutrophil-to-lymphocyte ratio (NLR) is a low-cost readout of both. Methods: Preregistered secondary analysis of open clinical laboratory data (NASA Open Science Data Repository OSD-569 and OSD-575) from the four Inspiration4 crew members, each sampled seven times: three draws before launch, one the day after return (R+1) and three during recovery (R+45 to R+194). Log-transformed NLR was modelled with a linear mixed model with a random intercept per crew member and Kenward-Roger inference. Lymphocyte and eosinophil counts and C-reactive protein were secondary outcomes with false discovery rate correction. Results: All 28 draws were analysed. NLR at R+1 did not differ from pre-flight (fold change 1.04; 95% CI 0.81 to 1.34; p = 0.73); two crew members increased (+25% and +46%) and two decreased (-27% and -11%). During recovery NLR was 23% lower than pre-flight (fold change 0.77; 95% CI 0.64 to 0.92; p = 0.005). No secondary outcome changed after correction; lymphocytes were 18% lower at R+1 (95% CI -35% to +4%; q = 0.31). Between-person differences explained 58% of the variance. An ordinary regression ignoring repeated measures missed the recovery effect (p = 0.08). Conclusions: A 3-day orbital flight produced no consistent leukocyte stress signature one day after return. The lower NLR during recovery suggests that pre-flight values, not recovery values, deviate from the resting state, which has implications for how baselines are defined in short-duration spaceflight studies.

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Plasma Neurofilament Light Chain is Markedly Elevated in General Hospital Inpatients with Delirium

Kang, M. J.; Eratne, D.; Borchard, T.; Patel, K.; Malpas, C. B.; Dang, C.; Storer, M.; Bhalala, O. G.; Yu, J. J.; Santillo, A. F.; Forbes, M.; Zetterberg, H.; Farrand, S.; Loi, S. M.; Mitchell, P. B.; Hopwood, M.; Smith, J.; Chiang, C.; Velakoulis, D.

2026-10-20 geriatric medicine 10.64898/2026.10.18.26365854 medRxiv
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Objective: To determine whether plasma neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) are elevated in hospitalised patients with delirium relative to patients with dementia and primary psychiatric disorders (PPD). Methods and analysis: This was a cross-sectional observational study conducted at the Royal Melbourne Hospital, Melbourne, Australia, between April and October 2024, with comparator samples from a research biobank. In Phase 1 (Delirium Discovery Cohort), we measured plasma NfL and GFAP using the Single molecule array (Simoa) platform in hospitalised patients with delirium and compared them with dementia and PPD groups. Biomarker concentrations were the primary outcome and were compared using general linear models adjusted for age, sex, and estimated glomerular filtration rate, with bootstrapped confidence intervals. Discriminative performance was assessed as a secondary outcome using receiver operating characteristic (ROC) curve analysis. In Phase 2, we applied this threshold to independent dementia and PPD groups. Results: In Phase 1 (n =176), inpatients with delirium showed higher concentrations of both NfL and GFAP than patients with dementia ({beta} = 0.78; 95% CI [0.37, 1.20] and {beta} = 0.39 [0.07, 0.73] respectively) or PPD groups ({beta} = 1.17; [0.69, 1.66] and {beta} = 0.83 [0.51, 1.24] respectively). ROC curve analysis for differentiating delirium from dementia and PPD groups yielded an optimal NfL threshold of 24.1 pg/mL (AUC = 0.89, 96% sensitivity, 70% specificity). In comparison, GFAP showed lower accuracy (AUC = 0.85), and combining NfL with GFAP (AUC = 0.90) did not significantly improve performance. In Phase 2 (n = 154), the NfL threshold of > 24 pg/ml maintained strong performance (AUC = 0.95, 96% sensitivity, and 77% specificity). Conclusions: Plasma NfL shows promise as a biomarker for delirium in hospitalised patients, distinguishing it with high sensitivity from patients with dementia and PPD. Larger multicentre studies are needed to refine cut-offs, evaluate temporal dynamics, and determine integration into acute hospital delirium pathways.

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Multimorbidity and cardiometabolic clustering among university employees: findings from a comprehensive health assessment program in India

Jagtap, A. H.; Ingole Patil, A. S.; Kudale, A. M.

2026-10-20 occupational and environmental health 10.64898/2026.10.20.26365860 medRxiv
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Abstract Objective To estimate the burden and patterns of multimorbidity and cardiometabolic multimorbidity among university employees undergoing a comprehensive health assessment programme, and to examine demographic and behavioural factors associated with multimorbidity. Design Cross-sectional study. Setting A public university in Maharashtra, India. Participants A total of 266 university employees who underwent a comprehensive health assessment were included. Main outcome measures Multimorbidity was defined as the presence of two or more of nine chronic conditions: hypertension, diabetes mellitus, dyslipidaemia, ischaemic heart disease, chronic kidney disease, thyroid disease, stroke, chronic obstructive pulmonary disease and cancer. Cardiometabolic multimorbidity was defined as the presence of two or more of hypertension, diabetes mellitus, dyslipidaemia, ischaemic heart disease and chronic kidney disease. Results Hypertension was identified in 119 participants (44.7%), comprising 50 participants with pre-existing hypertension and 69 newly identified during the assessment. Dyslipidaemia was present in 189 (71.1%) and diabetes mellitus in 45 (16.9%). Overall, 108 participants (40.6%) had multimorbidity and 103 (38.7%) had cardiometabolic multimorbidity. The prevalence of multimorbidity increased progressively with age, from 17.5% among participants aged <30 years to 83.3% among those aged [&ge;]60 years. The predominant exact multimorbidity patterns were hypertension with dyslipidaemia alone (49 participants) and hypertension, diabetes mellitus and dyslipidaemia (27 participants). Overall, 173 participants (65.0%) had at least one newly identified hypertension, diabetes mellitus or dyslipidaemia diagnosis. In multivariable logistic regression, age (adjusted OR [aOR] 1.058 per year, 95% CI 1.027 to 1.091), BMI (aOR 1.163 per kg/m2, 95% CI 1.076 to 1.257) and tobacco use (aOR 3.296, 95% CI 1.377 to 7.888) were independently associated with multimorbidity. The model had an area under the receiver operating characteristic curve of 0.731. Conclusion Multimorbidity affected approximately two in five university employees, with cardiometabolic conditions accounting for most of the observed disease clustering. Comprehensive health assessment identified a substantial burden of previously unrecognised chronic disease. Integrating institutional or occupational health assessment with longitudinal primary care follow-up may provide an opportunity for earlier detection, risk-factor modification and coordinated management of multimorbidity. Keywords: Multimorbidity; cardiovascular diseases; hypertension; diabetes mellitus; dyslipidaemia; occupational health; university employees; India

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Persistent gut microbiota alterations after ischemic stroke are modifiable by probiotic intervention

Melton, P.; Sorbie, A.; Aho, V. T. E.; Haslinger, C.; Zimmermann, M.; Marut, W.; Jaeger, C.; Wilmes, P.; Benakis, C.; Liesz, A.

2026-10-20 neurology 10.64898/2026.10.15.26365107 medRxiv
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The gut-brain axis has emerged as a critical modulator in neurological diseases, including stroke. While acute post-stroke dysbiosis is well established, it remains unclear whether these alterations persist long-term and can be therapeutically modulated. This study addresses this gap through integrated metagenomic and metabolomic profiling in two independent clinical stroke cohorts, complemented by experimental models. Experimental stroke induced persistent changes in gut microbiota composition and altered short-chain fatty acid profiles. In patients, microbiota composition remained distinct from controls up to three months after ischemic stroke or transient ischemic attack (TIA), accompanied by persistent reductions in propionic and valeric acid and reduced abundance of Prevotella-associated microbial signatures. We performed a randomized, double-blind interventional trial (PRISE) testing a multispecies probiotic versus placebo, using household members as additional controls. Probiotic intervention led to microbiome compositional changes with increased abundance of beneficial taxa and significantly improved functional recovery. The tested probiotic strains showed anti-inflammatory and antioxidant effects in vitro. These findings suggest that targeted modulation of the microbiome represents a promising therapeutic avenue to improve chronic stroke recovery, warranting validation in larger Phase III clinical trials.

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Dysfunctional Sleep Beliefs and Attitudes in Major Depressive Disorder: Dimensional Associations with Clinical Phenotypes and Gut-Neuroimmune-Metabolic-Oxidative Pathways

Wang, M.; Niu, M.; Luo, X.; Chen, X.; Liu, H.; Chen, T.; Almulla, A. F.; Zhang, Y.; Li, J.; Maes, M.

2026-10-20 psychiatry and clinical psychology 10.64898/2026.10.18.26365736 medRxiv
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Abstract Background: Insomnia is highly prevalent in major depressive disorder (MDD), yet the clinical and biological significance of dysfunctional beliefs and attitudes about sleep (DBAS) in MDD remains poorly understood. We examined whether distinct DBAS dimensions are associated with insomnia severity, depressive phenotypes, and neuroimmune-metabolic-oxidative (NIMETOX) biomarkers. Methods: DBAS-30 dimensions, clinical phenotypes, and NIMETOX biomarkers were assessed in 87 hospitalized patients with MDD and 31 healthy controls. Principal component analysis (PCA) was used to ascertain DBAS cognitive dimensions, and associations were examined using multivariable analyses. Results: Compared with controls, MDD patients showed lower scores on "perceived consequences of insomnia," "sleep-related worry and helplessness," and "medication-related beliefs," but higher "causal attributions to aging or biochemical imbalance" scores. A composite DBAS score reflecting these 4 MDD-associated cognitive dimensions was constructed, labeled DBAS dimensional index (DBAS-DI). This score was lower in MDD and inversely associated with Insomnia Severity Index (ISI) scores, overall MDD severity, physiosomatic symptoms, current suicidal ideation, and recurrence of illness. DBAS-DI and the expectations domain jointly explained 35.4% of the variance in ISI scores, with inverse and positive associations, respectively. The DBAS-DI score was inversely associated with indices of the acute-phase inflammatory response, oxidative stress, fecal branched-chain short-chain fatty acids (SCFAs) and positively associated with serum antioxidant capacity and protective SCFAs, such as acetate, propionate, and butyrate. Conclusions: DBAS abnormalities in MDD extend beyond insomnia-related cognitions and are associated with illness severity, suicidality, recurrence, and NIMETOX alterations. These findings suggest that dysfunctional sleep-related cognitions are embedded within broader immune-oxidative and gut microbial-metabolic processes that may contribute to the insomnia-depression interface.

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Spectral power and functional connectivity of resting EEG in people exposed to armed conflict and controls

Nitola-Pulido, L.; Bonilla, D. S.; Herrera Murcia, E.; Reyes Gavilan, P. A.; Santamaria-Garcia, H.

2026-10-19 psychiatry and clinical psychology 10.64898/2026.10.15.26365676 medRxiv
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Exposure to armed conflict can leave persistent effects on mental health, yet its neurophysiological correlates remain poorly characterized, particularly in populations exposed to prolonged violence outside narrowly defined post traumatic stress disorder samples. Here we examined resting state electroencephalographic activity in 122 Colombian adults, including 74 participants exposed to armed conflict and 48 controls. Eyes closed EEG was analysed for 240 seconds per participant. We quantified absolute and relative spectral power across delta, theta, alpha and beta bands and regional functional connectivity using weighted phase lag index in theta, alpha and beta. Group comparisons were adjusted for age, education, sex and assessment year, with correction across 78 EEG contrasts. Median occipital and global alpha power was lower in exposed participants, although adjusted estimates were close to the null and confidence intervals were broad. Temporal theta relative power was lower in exposed participants at nominal significance, but this association did not survive Holm correction. No spectral power or regional connectivity contrast remained significant after multiple testing correction. Exploratory associations between EEG measures and MoCA performance were modest in participants with confirmed scores. These findings provide a systematic characterization of resting EEG after exposure to armed conflict in a population shaped by prolonged violence and displacement. They also indicate that large or widespread alterations in resting spectral power and connectivity were not detectable with the current sample and analytical framework, while defining candidate signals and methodological priorities for larger studies of conflict related brain health.

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Biological aging markers in South African women with HIV and variable exposure to childhood maltreatment

Maloka, K. M. S.; Spies, G.; du Plessis, S.; Hemmings, S. M. J.; Letendre, S.; Seedat, S.; Womersley, J. S.

2026-10-16 hiv aids 10.64898/2026.10.15.26365601 medRxiv
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Introduction: HIV and childhood maltreatment (CM) are both chronic stressors that disproportionately affect women, with each contributing to accelerated biological aging. Whether biological aging markers are convergent and associate with HIV and CM is unclear. Methods: We studied 238 women (122 with HIV), characterised for CM severity, and assessed biological aging using absolute telomere length (aTL), mitochondrial DNA copy number (mtDNAcn), magnetic resonance imaging-based brain-predicted age difference (MRI-BPAD), and DNA methylation age (DNAmAge) clocks. CM was measured with the Childhood Trauma Questionnaire-Short Form total score. We examined intercorrelations among biological aging markers to assess convergence and conducted linear regression models to test moderation by HIV status and CM severity. Results: PWH had shorter aTL, lower MRI-BPAD, and higher Horvath age acceleration (HorvathAA), HannumAA, PhenoAA, and extrinsic epigenetic age acceleration (EEAA). CM had limited associations with biological aging markers. Absolute TL correlated weakly with mtDNAcn (p = 0.36), PhenoAA (p = -0.18), and EEAA (p = -0.18), while MRI-BPAD correlated weakly with PhenoAA (r = 0.20). DNAmAge clocks were moderately to strongly intercorrelated (r = 0.35 - 0.93). No robust two- or three-way moderation effects were observed after false discovery rate correction. Conclusion: Our findings support a multidimensional pattern of biological aging, with substantial convergence among epigenetic aging measures but limited relationships across different markers, largely independent of HIV status and CM severity. Longitudinal approaches are needed to clarify how distinct biological aging markers relate to one another and to health outcomes over time in vulnerable populations.

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APOE ε4 Modifies the Association of Left Atrial Remodeling With Brain Aging

Badea, A.; Xu, J.; Laskowitz, D. T.; Badea, C. T.

2026-10-20 neurology 10.64898/2026.10.14.26365550 medRxiv
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INTRODUCTION: Whether APOE e4 modifies relationships between subclinical cardiac phenotypes and brain structure is unknown. METHODS: In Framingham Heart Study Offspring participants, we related antecedent echocardiographic remodeling (Examinations 4-6) to repeated brain MRI, and cardiac magnetic resonance phenotypes to regional cortical morphometry, testing cardiac x APOE e4 interactions with false-discovery-rate (FDR) correction and permutation testing of the regional screen. RESULTS: APOE e4 modified the association between antecedent left atrial (LA) remodeling and subsequent lateral ventricular expansion (beta=-0.00858, P=1.45 x 10^-4, q=0.0023; N=1,305; 3,787 MRI observations), the only FDR-significant result of 16 longitudinal tests, including with participant-specific MRI-time slopes (q=0.034); it weakened when intracranial volume x MRI time was modeled. Four regional ventricular cardiac x APOE e4 interactions met within-family FDR criteria, but their number was consistent with chance (permutation P=0.70). Maximum LA volume index showed an APOE e4-dependent association with left middle-occipital cortical-thickness variability (whole-brain q=0.017; permutation P=0.041) that persisted after ventricular adjustment. Cardiac phenotypes and trajectories showed no FDR-significant APOE e4-dependent associations with plasma Abeta42/40, p-tau181, GFAP, or NfL, and adjustment for these biomarkers changed the regional interactions by at most 3.2%. Allen Human Brain Atlas data showed cholesterol-biosynthesis enrichment in the right superior frontal cortex, implicated by the LV end-systolic volume interaction, but without convergent pathway evidence. DISCUSSION: APOE e4 modified atrial-brain relationships, with the strongest evidence linking antecedent atrial remodeling to later ventricular expansion. Replication with prespecified models is needed.

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Multiple Organ Dysfunction Trajectory Phenotypes After Severe Trauma Are Associated With Distinct Immune Profiles and Outcomes

Ding, H.; Cox, M.; Qiu, Q.; Mirabadi, N.; Bobrovnikov, D.; Gerbino, K.; Scherler, K.; Walters, K.; O'Keefe, G.; Brakenridge, S.

2026-10-19 intensive care and critical care medicine 10.64898/2026.10.15.26365695 medRxiv
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BACKGROUND Traditional organ dysfunction classifications after severe trauma rely on binary categories (e.g., chronic critical illness [CCI] versus rapid recovery), which likely oversimplify the true heterogeneity of postinjury organ dysfunction trajectories and their underlying immune-biologic drivers. We hypothesized that severely injured trauma patients demonstrate multiple, distinct organ dysfunction phenotypes distinguished by unique immune signatures. METHODS We performed a prospective, longitudinal, observational cohort study of severely injured trauma patients at high risk for multiple organ dysfunction at a single Level 1 trauma center. Organ dysfunction was quantified daily through 28 days, death, or discharge using a trauma-specific modified Sequential Organ Failure Assessment (mSOFA) score excluding the neurologic subdomain to isolate systemic organ dysfunction from traumatic brain injury. We utilized group-based trajectory modeling to identify longitudinal mSOFA phenotypes. Plasma immune protein trajectories were compared across phenotypes using mixed-effects models with time interaction. RESULTS Sixty-nine patients were enrolled. Trajectory modeling identified five mSOFA phenotypes (c1-c5) with differences in resuscitation requirements, shock severity, and 28-day mortality, but not baseline demographics, injury severity, or early physiologic parameters. The phenotypes revealed organ dysfunction heterogeneity not fully captured by CCI/rapid recovery classification. Forty of 92 measured immune markers showed phenotype-differentiated trajectories (FDR<0.1). The most fulminant phenotype (c5) was distinguished by IL-17C, CXCL5, and CXCL6, implicating epithelial-barrier and neutrophil-trafficking mechanisms. The phenotype with highest CCI incidence (c3) was distinguished by rising CXCL9, ARTN, and TWEAK, implicating Th1 polarization and tissue-inflammation/repair signaling. The clinically distinct, older-age phenotype (c4) carried the largest differentiating signature (29 proteins), spanning renal injury/repair, endothelial activation, and adaptive lymphocyte modulation. CONCLUSIONS Organ dysfunction after severe trauma is more biologically heterogeneous than traditional clinical classifications suggest. Distinct mSOFA trajectory phenotypes correspond to distinct immune signatures, supporting separable pathobiology rather than a single axis of injury severity, with implications for phenotype-targeted precision immunomodulatory approaches in critical illness.

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Longitudinal associations between neuropsychiatric symptoms, structural and perfusion MRI changes in older adults with Mild Cognitive Impairment

Lombardi, G.; Leung, C. C.-Y.; Burge, R.; Zelaya, F.; Bhattacharyya, S.; Velayudhan, L.

2026-10-19 geriatric medicine 10.64898/2026.10.15.26364284 medRxiv
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Neuropsychiatric symptoms (NPS) are highly prevalent in Mild Cognitive Impairment (MCI), conceptualized as an intermediate clinical state between normal aging and dementia. Although neuroimaging studies have reported associations between NPS and brain alterations in MCI, longitudinal evidence on NPS and their relationship with multimodal MRI measures remains limited. We aimed to investigate (1) longitudinal changes in NPS, volumetric assessment and measurement of regional cerebral blood flow (CBF) within the medial temporal lobe (MTL); (2) associations between longitudinal changes in MRI measures and NPS; (3) whether baseline MRI measures predicted longitudinal changes in NPS. Thirty individuals with MCI aged over 65 years were recruited, of whom eighteen followed up for a mean period of 29 {+/-} 8.9 months. There were significant reductions in total grey matter and white matter volumes, together with volume loss in the bilateral hippocampus, bilateral parahippocampal gyrus and right entorhinal cortex (pFDR[&le;]0.05) over the follow up period. Volume loss in the right parahippocampal gyrus was associated with increase in aggression (pFDR<0.01), and CBF increase in the right hippocampus and parahippocampal gyrus was associated with worsening in agitation (pFDR<0.01). Furthermore, lower baseline volume of the right entorhinal cortex was associated with increase in aggression, and lower baseline CBF in the right hippocampus and parahippocampal gyrus was associated with worsening of agitation (pFDR<0.05). Our findings highlight the importance of identifying NPS in individuals with MCI and the role of structural and perfusion MRI measures as promising biomarkers for monitoring disease progression and improving risk prediction of conversion to dementia.