Plasma Biomarkers Research Articles

Improved prognosis prediction of idiopathic pulmonary arterial hypertension using targeted plasma proteomics in disease management

Abstract Background Idiopathic pulmonary arterial hypertension (IPAH), a special subgroup of PAH with unclear etiology, is characterized by rapid progression and poor prognosis underscoring the need for optimization of IPAH management and the accurate prediction of prognosis. However, it is disappointing that specific plasma biomarkers for IPAH management and prognosis are lacking in clinical practice. Up to date, the plasma biomarkers used for assessment of IPAH severity and prognosis are relied solely on indicators such as N-terminal prohormone of brain natriuretic peptide, or brain natriuretic peptide, which could reflect cardiac function but fail to promptly response to the dynamic change of disease condition due to the complexity of IPAH pathogenesis. Purpose We evaluated the prognostic value of plasma proteins in addition to current clinical predictors for prognosis prediction of IPAH. Methods Olink Immune-Response panel was used to measure 92 plasma proteins in a prospective IPAH cohort with 169 patients and a mean follow-up period of 2.4 ± 0.9 years. Six machine learning methods were used to construct predictive models, including plasma proteins-based Olink models, clinical parameters-based clinical models, and integrative models. Results A total of 18 proteins showed differential expression between patients with or without adverse clinical outcomes. Three proteins (STC1, CXADR, and IL6) were strongly correlated with clinical indicators of IPAH severity and their concentrations showed upward trends along with increased risk stratification. Elevated levels of STC1, CXADR, and IL6 are all associated with an increased risk of adverse clinical events, indicated by survival analysis, restricted cubic splines, and multivariable Cox regression analysis (STC1 HR=3.474, 95%CI: 1.129-10.692, P=0.030; CXADR: HR=1.602, 95%CI: 1.074-2.387, P=0.021; IL6: HR=1.883, 95%CI: 1.376-2.576, P<0.001). The inclusion of these three proteins into the predictive model could significantly increase the predictive power on the basis of the clinical model (AUC: 0.746 vs 0.626). Conclusions High levels of STC1, CXADR, and IL6 in plasma were associated with severe clinical phenotype and increased risk of adverse clinical events in patients with IPAH. These plasma proteins could significantly improve the prognostic performance of pre-existing clinical models, facilitating the clinical management of IPAH patients.The predictive efficient of models

Impact of cardiovascular risk factors in cardiac (reverse) remodelling induced by pregnancy

Abstract Introduction Haemodynamic overload during pregnancy induces cardiac remodelling, characterised by cardiac hypertrophy and chamber enlargement, associated with deterioration of diastolic function, despite preservation of the systolic function. After delivery, the woman's heart undergoes reverse remodelling(RR), and myocardial function and structure normalise to their pre-gravid state. The impact of cardiovascular risk factors(CRF) in cardiac remodelling and RR, namely, on cardiac function and structure, is variable and remains to be clarified. Purpose To characterise cardiac remodelling and RR during pregnancy and postpartum, respectively, and to investigate CRF's impact in these processes. Methods This prospective cohort study included volunteer pregnant women (healthy [H group] or obese and/or hypertensive and/or with gestational diabetes [CRF group]) recruited in two tertiary centres between 2019 and 2022. Women were evaluated by transthoracic echocardiography at the 1st trimester [1T,10-15 weeks, baseline], 3rd trimester [3T,30-35 weeks, peak of cardiac remodelling] of pregnancy as well as at the 1st, 6th and 12th month after delivery (during RR). Blood samples were collected in each evaluation moment to quantify plasma troponin I (cTnI), procollagen I COOH-terminal propeptide (PICP), ST2/IL33-receptor, C-reactive protein (CRP) and relaxin-2 by ELISA. Generalised linear mixed-effects models were used to evaluate the extent of RR and its potential predictors. Results We included 130 pregnant women with a median age of 33 [30,36] years, 41.5% with at least one CRF. As shown in Table 1, pregnant women developed cardiac hypertrophy with significant atrial and ventricular enlargement from 1T to 3T in both groups. A significant rise in filling pressures was also documented. During postpartum, a significant regression of cardiac hypertrophy and dilation was verified in the two study groups, accompanied by a significant decrease of E/e’ as soon as 1 month after delivery. These cardiac anatomical and functional adaptations induced by pregnancy were accompanied by a significant reduction in plasma cTnI, PICP, ST2/IL33-receptor, CRP and relaxin-2 levels from 3T to 6-months after delivery. Compared to the healthy pregnant women, the CRF group showed higher relative wall thickness (RWT) for all time points of the follow-up period, with similar values of indexed cardiac mass and volumes. Pregnant women with CRF revealed higher E/e’, contrasting with lower ejection fraction and worse global longitudinal strain. Conclusion The significant cardiac reverse remodelling occurred as soon as 1 month after delivery, returning to basal values 6 months postpartum, supported by a significant reduction of levels of plasma biomarkers related to myocardial injury, repair, fibrosis, and inflammation. Pregnant women with CRF showed higher RWT, impaired relaxation and subclinical LV dysfunction when compared with healthy women at all time points of the study.

Biomarker Assessment in Parkinson's Disease Dementia and Dementia with Lewy Bodies by the Immunomagnetic Reduction Assay and Clinical Measures.

Plasma biomarker assays provide an opportunity to reassess whether Alzheimer's disease, Parkinson's disease dementia (PDD), and dementia with Lewy bodies (DLB) plasma biomarkers are diagnostically useful. We hypothesized that immunomagnetic reduction (IMR) of plasma biomarkers could differentiate between patients with PDD and DLB and healthy patients when combined with established clinical testing measures. Plasma samples from 61 participants (12 PDD, 12 DLB, 37 controls) were analyzed using IMR to quantify amyloid-β 42 (Aβ42), total tau (t-tau), phosphorylated tau at threonine 181 (p-tau181), and α-synuclein (α-syn). Receiver operating characteristic curve (ROC) analysis was used to obtain sensitivity, specificity, and area under the ROC curve. Biomarker results were combined with clinical measures from the Unified Parkinson's Disease Rating Scale (UPDRS), Montreal Cognitive Assessment, and Hoehn-Yahr stage to optimize diagnostic test performance. Participants with PDD had higher α-syn than those with DLB and healthy participants and were distinguishable by their biomarker products Aβ42×p-tau181 and Aβ42×α-syn. Patients with DLB had higher p-tau181 than those with PDD and healthy participants and were distinguishable by their concentrations of α-syn×p-tau181. Plasma α-syn plus UPDRS versus either test alone increased sensitivity, specificity, and AUC when healthy patients were compared with those with PDD and DLB. Combined clinical examination scores and plasma biomarker products demonstrated utility in differentiating PDD from DLB when p-tau181 was combined with UPDRS, α-syn was combined with UPDRS, and α-syn×p-tau181 was combined with UPDRS. In this pilot study, IMR plasma p-tau181 and α-syn may discriminate between PDD and DLB when used in conjunction with clinical testing.

Plasma Protein Biomarkers and Long-Term Cardiovascular Mortality Risk in Patients With Chronic Coronary Heart Disease.

Protein biomarkers that reflect different pathophysiological pathways have been associated with the risk of adverse cardiovascular events. However, it is uncertain whether these associations are sustained with increasing years after the biomarkers are measured. In this cohort study, 7745 patients with coronary heart disease who participated in the LIPID (Long-Term Intervention With Pravastatin in Ischemic Disease) trial, BNP (B-type natriuretic peptide), troponin I, cystatin-C, C-reactive protein, d-dimer and midregional proadrenomedullin were measured at baseline and after 1 year. Discrimination of plasma biomarker concentrations for cardiovascular death were evaluated in landmark analyses from 1 year for the next 5 years of the randomized trial, and for 10 additional years after trial completion. All 6 biomarkers were associated with risk of cardiovascular death (n=1903) both during and after the clinical trial (each P<0.001). C-statistics for BNP were 0.706 and 0.704; cystatin-C, 0.686 and 0.693; troponin I, 0.686 and 0.689; C-reactive protein, 0.655 and 0.684; d-dimer, 0.670 and 0.679, and midregional adrenomedullin, 0.686 and 0.688, respectively. In multivariable models, adding all 6 biomarkers to models with clinical risk factors increased the C-statistic for cardiovascular death from 0.709 to 0.775 during the clinical trial, and from 0.713 to 0.751 during 10-year follow-up after the randomized trial (P<0.001 for both). In patients with chronic coronary heart disease, biomarkers that reflect different pathophysiological pathways are associated with the risk of cardiovascular death for at least the next 15 years.

Neuronal plasma biomarkers in acute ischemic stroke.

Early imaging-based detection of acute ischemic stroke (AIS) has improved in the era of reperfusion therapy. Despite of this, prognosis of outcome after AIS remains a challenge. Therefore, parameters that support clinical decision making are sought. Blood-based biomarkers have the potential to provide valuable information in addition to the established prognostic factors. Neuronal biomarkers of acute or degenerative neuronal injury have shown to be reliably detected in plasma. These biomarkers are well-established in neurodegenerative pathology, such as Alzheimer's disease. In this study, we explored the association between stroke diameter and plasma biomarkers for neuronal injury and tau pathophysiology (brain-derived tau [BD-tau], phosphorylated-tau-217 [p-tau21] and neurofilament light [NfL]) in patients (n = 193) admitted to the acute ward, Akershus University Hospital. All patients received a final diagnosis of AIS, transient ischemic attack or stroke mimics. Blood samples were obtained the day after admission. We find that levels of BD-tau (p = .004) and NfL (p = .011) were higher after AIS than in patients with stroke mimics. The cortical stroke diameter correlated with BD-tau (tau-b = 0.64, p < .001) and p-tau217 (tau-b = 0.36, p = .003). Linear regression confirmed BD-tau to be the strongest variable associated with stroke diameter, pointing to the potential clinical value of plasma BD-tau in outcome prediction after AIS.

Pathophysiological Markers of Acute Respiratory Distress Syndrome Severity Are Correlated With Ventilation-Perfusion Mismatch Measured by Electrical Impedance Tomography.

Pulmonary ventilation/perfusion (V/Q) mismatch measured by electrical impedance tomography (EIT) is associated with the outcome of patients with the acute respiratory distress syndrome (ARDS), but the underlying pathophysiological mechanisms have not been fully elucidated. The present study aimed to verify the correlation between relevant pathophysiological markers of ARDS severity and V/Q mismatch. Prospective observational study. General ICU of a university-affiliated hospital. Deeply sedated intubated adult patients with ARDS under controlled mechanical ventilation. Measures of V/Q mismatch by EIT, respiratory mechanics, gas exchange, lung imaging, and plasma biomarkers. Unmatched V/Q units were assessed by EIT as the fraction of ventilated nonperfused plus perfused nonventilated lung units. At the same time, plasma biomarkers with proven prognostic and mechanistic significance for ARDS (carbonic anhydrase 9 [CA9], hypoxia-inducible factor 1 [HIF1], receptor for advanced glycation endproducts [RAGE], angiopoietin 2 [ANG2], gas exchange, respiratory mechanics, and quantitative chest CT scans were measured. Twenty-five intubated ARDS patients were included with median unmatched V/Q units of 37.1% (29.2-49.2%). Unmatched V/Q units were correlated with plasma levels of CA9 (rho = 0.47; p = 0.01), HIF1 (rho = 0.40; p = 0.05), RAGE (rho = 0.46; p = 0.02), and ANG2 (rho = 0.42; p = 0.03). Additionally, unmatched V/Q units correlated with plateau pressure (r = 0.38; p = 0.05) and with the number of quadrants involved on chest radiograph (r = 0.73; p < 0.01). Regional unmatched V/Q units were correlated with the corresponding fraction of poorly aerated lung tissue (r = 0.62; p = 0.01) and of lung tissue weight (rho: 0.51; p = 0.04) measured by CT scan. In ARDS patients, unmatched V/Q units are correlated with pathophysiological markers of lung epithelial and endothelial dysfunction, increased lung stress, and lung edema. Unmatched V/Q units could represent a comprehensive marker of ARDS severity, reflecting the complex organ pathophysiology and reinforcing their prognostic significance.

Dual on-the-move electrochemical immunoassays for the simultaneous determination of amyloid-β (1−42) and Tau in Alzheimer's patient samples

Here, we report catalytic micromotors (MM)-based electrochemical immunoassays for the on-the-move dual and simultaneous determination of Amyloid-β (Aβ-42) and Tau protein (Tau) (MMAβ-42-MMTau) as relevant Alzheimer’s disease biomarkers in brain tissue, cerebrospinal fluid, and plasma diagnosed samples. Combining the binding capacity of the antibody's functionalized polypyrrole (PPy) layer of MM with the self-propulsion from the PtNPs layer thanks to the decomposition of hydrogen peroxide, the approach yielded excellent detection limits (LODAβ-42=0.04 ng/mL, LODTau= 0.4 pg/mL) using low sample volumes (30 µL) and short analysis times (15 min) to detect both biomarkers. Quantitative analysis by MMAβ-42-MMTau was carried out without any clinical sample dilution (linear ranges are between 0.1 and 5 ng/mL for Aβ-42 and from 1 to 106 pg/mL in the case of Tau), highlighting the versatility of the approach to quantify Aβ-42 and Tau levels at different dynamic ranges. MMAβ-42-MMTau showed superior analytical capabilities to the single molecule counting technology (SMCx) during quantitative analysis in all sample classes tested, reporting a difference in quantitative levels for both biomarkers between healthy and diseased individuals and an increase in the levels with disease progression, except in plasma samples where no relationship between biomarker levels and disease progression was found.

Use of Biomarkers in Nutrition Intervention Studies of Children: A Scoping Review.

Obesity in youth is an increasingly prevalent public health concern worldwide. Lifestyle interventions aim to help participants establish healthy habits and reduce obesity-related disease risk by targeting physical activity and dietary habits. Most studies assess weight loss, but biomarkers may enable more rapid and comprehensive assessment of intervention success. This scoping review aims to synthesize the published literature on which biomarkers are assessed during interventions for pediatric obesity to inform future use. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search of five databases conducted in February 2022 returned 1579 unique and relevant articles published between 2006 and 2021. After screening titles, abstracts, and full text, four reviewers determined that 43 studies met eligibility requirements. Quality screening was conducted, and 97.7% of papers were of fair or good quality. Of the 43 studies, 47% reported measures of adipose-related signaling molecules inclusive of adipokines, 74% included insulin-related biomarkers, 63% reported lipid-related biomarkers, 40% reported proinflammatory cytokine biomarkers, 12% reported measures of skin and/or plasma carotenoids, 40% measured blood pressure, and 21% included liver enzymes. Sixty-seven percent of studies measured biomarkers in whole blood, 40% measured biomarkers in plasma, 56% measured biomarkers in serum, and 2% measured biomarkers in urine. This work summarizes the current use of biomarkers in lifestyle intervention studies enrolling children. These biomarkers could be clinically relevant for pediatric weight management interventions.

TGIRT-seq of Inflammatory Breast Cancer Tumor and Blood Samples Reveals Widespread Enhanced Transcription Impacting RNA Splicing and Intronic RNAs in Plasma.

Inflammatory breast cancer (IBC) is the most aggressive and lethal breast cancer subtype but lacks unequivocal genomic differences or robust biomarkers that differentiate it from non-IBC. Here, Thermostable Group II intron Reverse Transcriptase RNA-sequencing (TGIRT-seq) revealed myriad differences in tumor samples, Peripheral Blood Mononuclear Cells (PBMCs), and plasma that distinguished IBC from non-IBC patients and healthy donors across all tested receptor-based subtypes. These included numerous differentially expressed protein-coding gene and non-coding RNAs in all three sample types, a granulocytic immune response in IBC PBMCs, and over- expression of antisense RNAs, suggesting wide-spread enhanced transcription in both IBC tumors and PBMCs. By using TGIRT-seq to quantitate Intron-exon Depth Ratios (IDRs) and mapping reads to both genome and transcriptome reference sequences, we developed methods for parallel analysis of transcriptional and post-transcriptional gene regulation. This analysis identified numerous differentially and non-differentially expressed protein-coding genes in IBC tumors and PBMCs with high IDRs, the latter reflecting rate-limiting RNA splicing that negatively impacts mRNA production. Mirroring gene expression differences in tumors and PBMCs, over-represented protein-coding gene RNAs in IBC patient plasma were largely intronic RNAs, while those in non- IBC patients and healthy donor plasma were largely mRNA fragments. Potential IBC biomarkers in plasma included T-cell receptor pre-mRNAs and intronic, LINE-1, and antisense RNAs. Our findings provide new insights into IBC and set the stage for monitoring disease progression and response to treatment by liquid biopsy. The methods developed for parallel transcriptional and post- transcriptional gene regulation analysis have potentially broad RNA-seq and clinical applications.

The Association Between Constipation and Positron Emission Tomography and Blood-Based Biomarkers in Older Cognitively Unimpaired Adults with Higher Amyloid-β Burden.

Constipation may be linked to cognitive decline and a higher risk of Alzheimer's disease (AD). We aimed to investigate the association between constipation and positron emission tomography (PET) and blood-based AD biomarkers in older cognitively unimpaired (CU) adults with higher Aβ burden. Constipation was diagnosed according to Rome IV criteria and the severity of constipation was evaluated by using a validated self-reported questionnaire. The participants underwent the examination of plasma AD biomarkers and 18F-florbetapir PET and 18F-MK6240 PET scans; the latter was only performed in the validation cohort. Correlation and multiple linear regression analyses were used to investigate the association between constipation and AD biomarkers. Two cohorts were included in our study. A total of 404 older participants with 126 of whom Aβ-PET positive were enrolled in the development cohort. Multiple linear regression analysis showed constipation was associated with plasma t-Tau, p-Tau-181, and neurofilament light chain (NfL) in participants with Aβ-PET (+). Meanwhile, no/mild constipation was associated with lower Aβ-PET standard uptake value ratio. The association between constipation and plasma biomarkers was different in the subgroups stratified by age, sex and APOE ε4 genotype. The above associations were further validated in the validation cohort containing 36 Aβ-PET (+) participants. Importantly, no/mild constipation was associated with lessTau burden evaluated by 18F-MK6240 PET Braak stages. Our data indicate that no/mild constipation may be associated with lower plasma t-Tau, p-Tau-181, and NfL as well as less Aβ and Tau burden in older CU adults with Aβ deposition. Improving constipation and being away from defecation disorders may help reduce the risk of AD development.

CSF and Plasma Biomarkers in Patients With Iatrogenic Cerebral Amyloid Angiopathy.

Recently, a subset of patients affected by cerebral amyloid angiopathy (CAA) distinguished by atypical juvenile onset and a hypothesized iatrogenic origin (iatrogenic CAA, iCAA) has emerged. β-Amyloid (Aβ) accumulation evidenced by amyloid PET positivity or CSF Aβ decrease was included in the iCAA diagnostic criteria. Conversely, diagnostic criteria for sporadic CAA (sCAA) do not involve biomarker analysis. The aim of this study was to assess CSF and plasma levels of Aβ and tau in iCAA and sCAA cohorts. Patients affected by probable or possible CAA according to established criteria (Boston 2.0) were prospectively recruited at Fondazione IRCCS Carlo Besta and San Gerardo dei Tintori from May 2021 to January 2024. Patients with probable and possible iCAA or sCAA with available plasma and/or CSF samples were included. Clinical and neurologic data were collected, and levels of Aβ40, Aβ42, total tau, and phospho-tau (p-tau) were assessed in CSF and plasma by SiMoA and Lumipulse. 21 patients with iCAA (72% male, mean age at symptom onset 50 years [36-74]) and 32 patients with sCAA (44% male, mean age at symptom onset 68 years [52-80]) were identified. Cognitive impairment and cardiovascular risk factors in the sCAA cohort were more common compared with the iCAA cohort. Patients with sCAA and iCAA showed similar CSF levels for Aβ40 (p = 0.5 [sCAA, 95% CI 2,604-4,228; iCAA, 95% CI 1,958-3,736]), Aβ42 (p = 0.7 [sCAA, 95% CI 88-157; iCAA, 95% CI 83-155]), and total tau (p = 0.08 [sCAA, 95% CI 80-134; iCAA, 95% CI 37-99]). Plasma levels of Aβ40 (p = 0.08, 95% CI 181-222), Aβ42 (p = 0.3, 95% CI 6-8), and total tau (p = 0.4, 95% CI 3-6) were not statistically different in patients with sCAA compared with iCAA ones (Aβ40, 95% CI 153-193; Aβ42, 95% CI 6-7 and total tau, 95% CI 2-4). Despite presenting with a younger age at onset, fewer cardiovascular risk factors, and lower cognitive impairment, patients with iCAA demonstrated Aβ and tau levels comparable with elderly patients with sCAA, supporting a common molecular paradigm between the 2 CAA forms.

Neurodegenerative fluid biomarkers are enriched in human cervical lymph nodes.

In animal models, brain neurodegeneration biomarkers drain into cervical lymph nodes (CLNs), and this drainage function is reduced with ageing. If this occurred in humans, CLNs may provide a readily accessible measure of this aspect of protein clearance. We tested this hypothesis in people using ultrasound-guided fine needle aspiration (FNA). We measured amyloid-beta 40 and 42, phospho-Tau-181, glial-fibrillary-acidic-protein, and neurofilament-light using single molecule array in CLN aspirates and plasma from: i) a discovery cohort of 25 autoimmune patients, and from ii) plasma, CLNs and capillary blood in four healthy volunteers, an optimisation cohort. FNA was well-tolerated by all participants. In both cohorts, all biomarkers were detected in all plasma and CLN samples, other than neurofilament-light (8/17 of discovery cohort). CLN biomarker concentrations were significantly greater than plasma concentrations for all except neurofilament-light, most markedly for phospho-Tau-181 (266-fold; P<0.02), whose CLN concentrations decreased with age (Spearman r=-0.66, P=0.001). This study presents the first evidence that neurodegenerative biomarkers are detectable in human CLNs. Raised CLN:plasma biomarker ratios suggest their concentration in CLNs may offer a distinct compartment for minimally-invasive measurement of brain clearance and lymphatic drainage, with potential applicability to study of ageing and future clinical trials.

Biomarkers of endothelial dysfunction and cognition: A two-step IPD meta-analysis.

This study assessed the association of plasma biomarkers of endothelial dysfunction with cognitive performance and decline. Data from 9414 individuals from eight Dutch cohorts were included (Ø age-range: 57-93 years). Plasma biomarkers of endothelial dysfunction (soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble E-selectin) were combined into a standardized composite score. Cognitive outcomes included executive function, processing speed, immediate and delayed memory, attention, and language. Linear regressions and linear mixed models were run in the individual cohorts and standardized coefficients were subsequently pooled using random-effects meta-analyses. A higher endothelial dysfunction composite score was cross-sectionally associated with worse performance on executive function, processing speed, delayed memory, and attention, but not immediate memory or language (pooled β-range: -0.04, -0.02). We found no association with change in cognition over time. This comprehensive two-step, individual participant data (IPD) meta-analysis showed a small, consistent cross-sectional association between endothelial dysfunction and worse cognitive performance across multiple domains but no support for a longitudinal association. Prior evidence on endothelial dysfunction (ED) biomarkers and cognition is conflicting. This two-step, individual participant data (IPD) meta-analysis used data from eight Dutch cohorts. ED was consistently associated with concurrent cognition. ED was not associated with a change in cognition over time. The association of ED with current cognition may be generic.

From Organotypic Mouse Brain Slices to Human Alzheimer’s Plasma Biomarkers: A Focus on Nerve Fiber Outgrowth

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by memory loss and progressive deterioration of cognitive functions. Being able to identify reliable biomarkers in easily available body fluids such as blood plasma is vital for the disease. To achieve this, we used a technique that applied human plasma to organotypic brain slice culture via microcontact printing. After a 2-week culture period, we performed immunolabeling for neurofilament and myelin oligodendrocyte glycoprotein (MOG) to visualize newly formed nerve fibers and oligodendrocytes. There was no significant change in the number of new nerve fibers in the AD plasma group compared to the healthy control group, while the length of the produced fibers significantly decreased. A significant increase in the number of MOG+ dots around these new fibers was detected in the patient group. According to our hypothesis, there are factors in the plasma of AD patients that affect the growth of new nerve fibers, which also affect the oligodendrocytes. Based on these findings, we selected the most promising plasma samples and conducted mass spectrometry using a differential approach and we identified three putative biomarkers: aldehyde-dehydrogenase 1A1, alpha-synuclein and protein S100-A4. Our method represents a novel and innovative approach for translating research findings from mouse models to human applications.

Supplementation with NAD+ Precursors for Treating Alzheimer's Disease: A Metabolic Approach.

Alzheimer's disease (AD) is a progressive neurocognitive disorder. There is no cure for AD. Maintenance on intracellular levels of nicotinamide adenine dinucleotide (NAD+) has been reported to be a promising therapeutic strategy for the treatment of AD. NAD+ precursors that represent candidate targets include nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR). This systematic review provides insights into the potential therapeutic value of NAD+ precursors including NMN and NR, for the treatment of AD using preclinical and clinical studies published in the last 5 years. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol was followed to systematically search the literature using two databases. We found 3 studies that used NMN to treat AD in preclinical murine models. However, human clinical trials using NMN as a therapeutic intervention in AD was not available in the current literature. We also found 4 studies that investigated the potential benefits of NR for the treatment of AD in preclinical models. We also found 2 human clinical trials that showed marked improvements in plasma and neuroimaging biomarkers, and cognitive measures following supplementation with NR. Results of preclinical and clinical studies confirm the potential benefits of NAD+ precursors for the treatment of AD. However, further clinical studies are required to confirm the increasingly important value of NAD+ precursors as effective pharmacological interventions in the clinic.

P08.06.B TARGETED PLASMA METABOLOMICS DETECTS A METABOLIC SIGNATURE POTENTIALLY RELEVANT FOR DIAGNOSIS AND PROGNOSIS IN PATIENTS WITH GLIOBLASTOMA

Abstract BACKGROUND Glioblastoma diagnosis is made initially with radiological examination and pathological examination of the resected tumor. Debut symptoms may vary and be mild in the beginning therefore diagnosis can be delayed. Additional un-invasive diagnostic strategies can be useful for diagnosis and clinical follow up. Moreover, despite glioblastoma being almost invariably fatal, there are no clinically established plasma biomarkers to define prognosis in patients with glioblastoma. MATERIAL AND METHODS In this study we employed flow injection analysis tandem mass spectrometry to compare the plasma metabolic profile of patients with GBM (n=51) and healthy controls (n=24). RESULTS Principal Component Analysis (PCA) and Partial Least Discriminant Analysis (PLS-DA) highlighted a distinctive glioblastoma signature. The best confusion matrix from the ROC curve built on two metabolites, GLU and GLN-LYS, provided specificity of 87% and sensitivity of 92%, with positive and negative predictive values of 95% and 88%, respectively. Multivariate survival analyses revealed that higher levels of ALA, MET, ORN, PHE, TYR were to be associated with a shorter overall survival. CONCLUSION These results are currently being evaluated prospectively and at different stages of disease in a larger cohort of patients with glioblastoma to identify plasma metabolic markers relevant for recurrence development.

Plasma lipidomic signatures of dementia with Lewy bodies revealed by machine learning, and compared to Alzheimer's disease

BackgroundDementia with Lewy Bodies (DLB) is a complex neurodegenerative disorder that often overlaps clinically with Alzheimer’s disease (AD), presenting challenges in accurate diagnosis and underscoring the need for novel biomarkers. Lipidomic emerges as a promising avenue for uncovering disease-specific metabolic alterations and potential biomarkers, particularly as the lipidomics landscape of DLB has not been previously explored. We aim to identify potential diagnostic biomarkers and elucidate the disease's pathophysiological mechanisms.MethodsThis study conducted a lipidomic analysis of plasma samples from patients with DLB, AD, and healthy controls (HCs) at Xuanwu Hospital. Untargeted plasma lipidomic profiling was conducted via liquid chromatography coupled with mass spectrometry. Machine learning methods were employed to discern lipidomic signatures specific to DLB and to differentiate it from AD.ResultsThe study enrolled 159 participants, including 57 with AD, 48 with DLB, and 54 HCs. Significant differences in lipid profiles were observed between the DLB and HC groups, particularly in the classes of sphingolipids and phospholipids. A total of 55 differentially expressed lipid species were identified between DLB and HCs, and 17 between DLB and AD. Correlations were observed linking these lipidomic profiles to clinical parameters like Unified Parkinson’s Disease Rating Scale III (UPDRS III) and cognitive scores. Machine learning models demonstrated to be highly effective in distinguishing DLB from both HCs and AD, achieving substantial accuracy through the utilization of specific lipidomic signatures. These include PC(15:0_18:2), PC(15:0_20:5), and SPH(d16:0) for differentiation between DLB and HCs; and a panel includes 13 lipid molecules: four PCs, two PEs, three SPHs, two Cers, and two Hex1Cers for distinguishing DLB from AD.ConclusionsThis study presents a novel and comprehensive lipidomic profile of DLB, distinguishing it from AD and HCs. Predominantly, sphingolipids (e.g., ceramides and SPHs) and phospholipids (e.g., PE and PC) were the most dysregulated lipids in relation to DLB patients. The lipidomics panels identified through machine learning may serve as effective plasma biomarkers for diagnosing DLB and differentiating it from AD dementia.

Effect of Time-Restricted Eating on Circulating Levels of IGF1 and Its Binding Proteins in Obesity: An Exploratory Analysis of a Randomized Controlled Trial

Obesity is associated with alterations in circulating IGF1, IGF1-binding proteins (IGFBPs), insulin, inflammatory markers, and hormones implicated in cardiovascular disease, diabetes, cancer, and aging. However, the effects of 4 and 6 h time-restricted eating (TRE) on circulating IGF1 and IGFBPs is uncertain. Objective: This study aimed to investigate the effects of TRE on plasma IGF1, IGFBP1, IGFBP2, and IGFBP3, and whether these effects were mediated by weight loss or body composition changes. Insulin sensitivity, glucose control, adipokines, and inflammatory markers were also examined. Design: An exploratory analysis of an 8-week randomized controlled trial implementing a daily TRE intervention was carried out. Participants/Setting: This study was conducted at the University of Illinois at Chicago in 2019. Participants with obesity were randomized to 4 or 6 h TRE (n = 35) or a control (n = 14) group. Plasma biomarkers were measured by ELISA at baseline and week 8. In a sub-analysis, participants were stratified into higher- (&gt;3.5%) and lower- (≤3.5%) weight-loss groups. Intervention: Participants fasted daily from 7 p.m. to 3 p.m. in the 4 h TRE group (20 h) and from 7 p.m. to 1 p.m. in the 6 h TRE group (18 h), followed by ad libitum eating for the remainder of the day. Controls received no dietary recommendations. Main outcome measures: IGF1, IGFBPs, hsCRP, and adipokines were the main outcome measures of this analysis. Statistical Analysis: Repeated measures ANOVA and mediation analysis were conducted. Results: Body weight significantly decreased with TRE (−3.6 ± 0.3%), contrasting with controls (+0.2 ± 0.5%, p &lt; 0.001). Significant effects of TRE over time were observed on plasma IGFBP2, insulin, HOMA-IR, and 8-isoprostane levels, without affecting other biomarkers. In the sub-analysis, IGFBP2 increased while leptin and 8-isoprostane decreased significantly only in the “higher weight loss” subgroup. Changes in insulin and HOMA-IR were related to TRE adherence. Conclusions: Eight-week daily 4 to 6 h TRE did not affect IGF1, IGFBP1, or IGFBP3 levels but improved insulin, HOMA-IR, and 8-isoprostane. IGFBP2 increased and leptin decreased when weight loss exceeded 3.5% of baseline.

Association of novel lipid indices with the white matter hyperintensities in cerebral small vessel disease: a cross-sectional study

BackgroundLipids are associated with atherosclerosis, and novel lipid indices have been recently identified to be closely linked to cardiovascular diseases. This study explored the association between four novel lipid indices and the white matter hyperintensities (WMHs) in patients diagnosed with cerebral small vessel disease (CSVD).MethodsBetween January 2023 and February 2024, 219 patients were recruited, including 165 patients with CSVD WMHs and 54 healthy controls. Based on WMHs severity, patients with CSVD were categorised into mild and moderate-to-severe cohorts using the Fazekas rating scale. The plasma levels of four novel lipid indices (low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio [LDL-C/HDL-C], triglyceride/high-density lipoprotein cholesterol ratio [TG/HDL-C], total cholesterol/high-density lipoprotein cholesterol ratio [TC/HDL-C], and non-high-density lipoprotein cholesterol [Non-HDL-C]), were rigorously monitored in the enrolled patients.ResultsA total of 165 patients with CSVD WMHs were enrolled, including 94 with mild WMHs and 71 with moderate-to-severe WMHs. Multivariable logistic regression analysis revealed that LDL-C/HDL-C, TG/HDL-C, TC/HDL-C, and Non-HDL-C levels were significantly associated with WMHs (all P ≤ 0.001). Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of plasma lipid levels for WMHs in patients with CSVD. The novel lipid indicators outperformed traditional lipid indicators in assessing the diagnostic capability of WMHs. The combined index of the four blood lipid indices had an optimal cutoff point (OCP) of 0.489, with 88.3% sensitivity and 60.6% specificity. The area under the curve (AUC) is 0.800 (95% confidence interval [CI], 0.731–0.869; P < 0.001). Compared with males (OR = 1.126, 95% CI = 0.779–1.628), females (OR = 2.484, 95% CI = 1.398–4.414; P for interaction = 0.023) had a higher risk of developing WMHs.ConclusionThis study demonstrates a significant association between four novel lipid indices and the cerebral WMHs in CSVD, highlighting the potential of these markers as novel plasma biomarkers and predictive indicators for assessing CSVD progression and guiding clinical management.

Head-to-head comparison of leading blood tests for Alzheimer's disease pathology.

Blood tests have the potential to improve the accuracy of Alzheimer's disease (AD) clinical diagnosis, which will enable greater access to AD-specific treatments. This study compared leading commercial blood tests for amyloid pathology and other AD-related outcomes. Plasma samples from the Alzheimer's Disease Neuroimaging Initiative were assayed with AD blood tests from C2N Diagnostics, Fujirebio Diagnostics, ALZPath, Janssen, Roche Diagnostics, and Quanterix. Outcomes measures were amyloid positron emission tomography (PET), tau PET, cortical thickness, and dementia severity. Logistic regression models assessed the classification accuracies of individual or combined plasma biomarkers for binarized outcomes, and Spearman correlations evaluated continuous relationships between individual plasma biomarkers and continuous outcomes. Measures of plasma p-tau217, either individually or in combination with other plasma biomarkers, had the strongest relationships with all AD outcomes. This study identified the plasma biomarker analytes and assays that most accurately classified amyloid pathology and other AD-related outcomes. Plasma p-tau217 measures most accurately classified amyloid and tau status. Plasma Aβ42/Aβ40 had relatively low accuracy in classification of amyloid status. Plasma p-tau217 measures had higher correlations with cortical thickness than NfL. Correlations of plasma biomarkers with dementia symptoms were relatively low.