Baseline C-Reactive Protein Levels and Life Prognosis in Parkinson Disease

The Contribution of Type 2 Diabetes to Parkinson's Disease Aetiology

Type 2 diabetes (T2D) and Parkinson's disease (PD) are chronic disorders that have a significant health impact on a global scale. Epidemiological, preclinical, and clinical research underpins the assumption that insulin resistance and chronic inflammation contribute to the overlapping aetiologies of T2D and PD. This narrative review summarises the recent evidence on the contribution of T2D to the initiation and progression of PD brain pathology. It also briefly discusses the rationale and potential of alternative pharmacological interventions for PD treatment.

Systemic inflammation and risk of Parkinson's disease: A prospective cohort study and genetic analysis

BACKGROUND

Multiple evidence has suggested the complex interplay between Parkinson's disease (PD) and systemic inflammation marked by C-reactive protein (CRP) and interleukin 6 (IL-6). Nevertheless, the findings across studies have shown inconsistency, and the direction of the effect remains controversial. Here, we aimed to explore the link between CRP and IL-6 and the risk of PD.

METHODS

Based on data from the UK Biobank, we investigated the association between baseline CRP and IL-6 and the risk of incident PD with Cox proportional hazards regression analysis. We further performed extensive genetic analyses including genetic correlation, polygenic risk score (PRS), and pleiotropic enrichment based on summary statistics from previous genome-wide association studies.

RESULTS

A higher level of CRP at baseline was associated with a lower risk of PD (HR = 0.85, 95 % CI: 0.79-0.90, P = 4.23E-07). The results remained consistent in the subgroup analyses stratified by sex, age and body mass index. From the genetic perspective, a significant negative genetic correlation was identified between CRP and PD risk (correlation: -0.14, P = 6.31E-05). Higher PRS of CRP was associated with a lower risk of PD (P = 0.015, beta = -0.04, SE = 0.017). Moreover, we observed significant pleiotropic enrichment for PD conditional on CRP, and identified 13 risk loci for PD, some of which are implicated in immune functionality and have been linked to PD, including CTSB, HNF4A, PPM1G, ACMSD, and NCOR1. In contrast, no significant association was identified between IL-6 and PD.

CONCLUSIONS

Systemic inflammation at baseline measured by CRP level is associated with decreased future risk of PD. These discoveries contribute to a deeper comprehension of the role of inflammation in the risk of PD, and hold implications for the design of therapeutic interventions in clinical trials.

How should we be using biomarkers in trials of disease modification in Parkinson's disease?

The recent validation of the α-synuclein seed amplification assay as a biomarker with high sensitivity and specificity for the diagnosis of Parkinson's disease has formed the backbone for a proposed staging system for incorporation in Parkinson's disease clinical studies and trials. The routine use of this biomarker should greatly aid in the accuracy of diagnosis during recruitment of Parkinson's disease patients into trials (as distinct from patients with non-Parkinson's disease parkinsonism or non-Parkinson's disease tremors). There remain, however, further challenges in the pursuit of biomarkers for clinical trials of disease modifying agents in Parkinson's disease, namely: optimizing the distinction between different α-synucleinopathies; the selection of subgroups most likely to benefit from a candidate disease modifying agent; a sensitive means of confirming target engagement; and the early prediction of longer-term clinical benefit. For example, levels of CSF proteins such as the lysosomal enzyme β-glucocerebrosidase may assist in prognostication or allow enrichment of appropriate patients into disease modifying trials of agents with this enzyme as the target; the presence of coexisting Alzheimer's disease-like pathology (detectable through CSF levels of amyloid-β42 and tau) can predict subsequent cognitive decline; imaging techniques such as free-water or neuromelanin MRI may objectively track decline in Parkinson's disease even in its later stages. The exploitation of additional biomarkers to the α-synuclein seed amplification assay will, therefore, greatly add to our ability to plan trials and assess the disease modifying properties of interventions. The choice of which biomarker(s) to use in the context of disease modifying clinical trials will depend on the intervention, the stage (at risk, premotor, motor, complex) of the population recruited and the aims of the trial. The progress already made lends hope that panels of fluid biomarkers in tandem with structural or functional imaging may provide sensitive and objective methods of confirming that an intervention is modifying a key pathophysiological process of Parkinson's disease. However, correlation with clinical progression does not necessarily equate to causation, and the ongoing validation of quantitative biomarkers will depend on insightful clinical-genetic-pathophysiological comparisons incorporating longitudinal biomarker changes from those at genetic risk with evidence of onset of the pathophysiology and those at each stage of manifest clinical Parkinson's disease.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Microorganisms associated with increased risk of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder that affects more than 7 million people worldwide. Its aetiology is unknown, although the hypothesis of a genetic susceptibility to environmental agents is accepted. These environmental agents include fungi, bacteria, and viruses. Three microorganisms are directly associated with a significantly increased risk of developing Parkinson's disease: the fungal genus Malassezia, the bacterium Helicobacter pylori, and the hepatitis C virus. If the host is vulnerable due to genetic susceptibility or immune weakness, these microorganisms can access and infect the nervous system, causing chronic neuroinflammation with neurodegeneration. Other microorganisms show an epidemiological association with the disease, including the influenza type A, Japanese encephalitis type B, St Louis, and West Nile viruses. These viruses can affect the nervous system, causing encephalitis, which can result in parkinsonism. This article reviews the role of all these microorganisms in Parkinson's disease.

C-reactive protein as the biomarker of choice to monitor the effects of exercise on inflammation in Parkinson's disease

Parkinson's disease (PD), a heterogeneous disease with no disease-modifying treatments available, is the fastest growing neurological disease worldwide. Currently, physical exercise is the most promising treatment to slow disease progression, with evidence suggesting it is neuroprotective in animal models. The onset, progression, and symptom severity of PD are associated with low grade, chronic inflammation which can be quantified by measuring inflammatory biomarkers. In this perspective, we argue that C-reactive protein (CRP) should be used as the primary biomarker for monitoring inflammation and therefore disease progression and severity, particularly in studies examining the impact of an intervention on the signs and symptoms of PD. CRP is the most studied biomarker of inflammation, and it can be detected using relatively well-standardized assays with a wide range of detection, allowing for comparability across studies while generating robust data. An additional advantage of CRP is its ability to detect inflammation irrespective of its origin and specific pathways, an advantageous characteristic when the cause of inflammation remains unknown, such as PD and other chronic, heterogeneous diseases.

Parkinson's disease and cardiovascular involvement: Edifying insights (Review)

Parkinson's disease (PD) is one of the most common neurodegenerative illnesses, and is a major healthcare burden with prodigious consequences on life-quality, morbidity, and survival. Cardiovascular diseases are the leading cause of mortality worldwide and growing evidence frequently reports their co-existence with PD. Cardiac dysautonomia due to autonomic nervous system malfunction is the most prevalent type of cardiovascular manifestation in these patients, comprising orthostatic and postprandial hypotension, along with supine and postural hypertension. Moreover, many studies have endorsed the risk of patients with PD to develop ischemic heart disease, heart failure and even arrhythmias, but the underlying mechanisms are not entirely clear. As importantly, the medication used in treating PD, such as levodopa, dopamine agonists or anticholinergic agents, is also responsible for cardiovascular adverse reactions, but further studies are required to elucidate the underlying mechanisms. The purpose of this review was to provide a comprehensive overview of current available data regarding the overlapping cardiovascular disease in patients with PD.

Type 2 Diabetes and Parkinson's Disease: A Focused Review of Current Concepts

Highly reproducible epidemiological evidence shows that type 2 diabetes (T2D) increases the risk and rate of progression of Parkinson's disease (PD), and crucially, the repurposing of certain antidiabetic medications for the treatment of PD has shown early promise in clinical trials, suggesting that the effects of T2D on PD pathogenesis may be modifiable. The high prevalence of T2D means that a significant proportion of patients with PD may benefit from personalized antidiabetic treatment approaches that also confer neuroprotective benefits. Therefore, there is an immediate need to better understand the mechanistic relation between these conditions and the specific molecular pathways affected by T2D in the brain. Although there is considerable evidence that processes such as insulin signaling, mitochondrial function, autophagy, and inflammation are involved in the pathogenesis of both PD and T2D, the primary aim of this review is to highlight the evidence showing that T2D-associated dysregulation of these pathways occurs not only in the periphery but also in the brain and how this may facilitate neurodegeneration in PD. We also discuss the challenges involved in disentangling the complex relationship between T2D, insulin resistance, and PD, as well as important questions for further research. © 2022 International Parkinson and Movement Disorder Society.

Association between C-reactive protein-albumin ratio and overall survival in Parkinson's disease using publicly available data: A retrospective cohort study

Background

At present, many studies have confirmed that inflammation plays a central role in Parkinson's disease (PD). The inflammatory index is related to the prognosis of the disease, but a single inflammatory index has some limitations. The C-reactive protein-albumin ratio (CAR) is a better marker of inflammation or nutritional status than C-reactive protein (CRP) or albumin (Alb), but there is limited study on the association between CAR and the overall survival (OS) of PD.

Object

To study the association between CAR and OS in PD patients.

Methods

All of these data were obtained from the Dryad Digital Repository, based on which we conducted a secondary analysis. The study was conducted by the Department of Neurology, the National Regional Center for Neurological Disorders, and the National Hospital of Utano study between March 2004 to November 2007. The final analytic sample included 235 PD patients with the outcome of survival or all-cause death from the study registration to the endpoint. In this study, univariate and multivariate COX regression analyses were used to calculate the adjusted hazard ratio (HR), with a 95% confidence interval (CI). In addition, the association between CAR and OS in PD patients was explored by Kaplan-Meier curve and subgroup analysis.

Results

This study included 235 PD patients with an average age of 62.25 years, including 135 females and 100 males, and 45 died during the follow-up period. CAR was associated with gender, modified Hoehn-Yahr stages (mH-Y), and Mini-Mental State Examination (MMSE) of PD patients. In the COX multivariate regression model, after adjusting the age, gender, PD duration, mH-Y, MMSE, and the non-steroidal anti-inflammatory drugs, CAR was found to be associated with the OS in PD (HR = 1.54, 95% CI = 1.01-2.34, p = 0.044). Subgroup analysis showed that the subgroup did not play an interactive role in the association between the prognosis of patients with CAR and PD (p for interaction >0.05), and the results remained stable.

Conclusions

The all-cause mortality of PD patients with a high level of CAR is higher, which indicates that the poor overall survival of PD patients is associated with the increase of CAR. The CAR may be a reliable prognostic biomarker for PD patients.

Laboratory prognostic factors for the long-term survival of multiple system atrophy

To elucidate the biomarkers related to survival in multiple system atrophy(MSA), we analyzed the predictability of retrospectively collected blood markers for survival in 650 probable MSA. High absolute neutrophil count, red-cell distribution width, C-reactive protein, erythrocyte sedimentation rate, and low hemoglobin, protein, albumin, and creatinine were correlated with higher mortality in MSA. Systemic alteration in inflammation and nutritional status in the early stage are associated with higher mortality in MSA.

Role of High-Sensitivity C-reactive Protein (Hs-CRP) in Non-communicable Diseases: A Review

Non-communicable diseases like cardiovascular diseases, cerebrovascular diseases, diabetes mellitus, and cancer are very common causes of death worldwide. Therefore, the need to search for novel, affordable, and easily accessible biomarkers and risk factors for non-communicable diseases continues, which can predict the future risk of having these diseases with greater accuracy and precision. In this context, among available biomarkers, high-sensitivity C-reactive protein (Hs-CRP) is considered to be the best-suited marker. Various drug intervention trials demonstrated positive results in reducing Hs-CRP in individuals with raised levels. Numerous pharmacological and non-pharmacologic interventions in the form of lifestyle modifications, exercise, and cessation of smoking are being investigated to study their effect on reducing serum C-reactive protein (CRP) levels.

This review article discusses the role of Hs-CRP and its isoforms in the pathogenesis of various disease conditions, factors affecting its serum concentration, its prognostic value, and its comparison with other risk factors. Further, its clinical significance in chronic inflammatory and degenerative diseases of the nervous system and other common non-communicable diseases, including recent advances in the management of various diseases, has also been discussed.

Serum albumin, cognitive function, motor impairment, and survival prognosis in Parkinson disease

The role of albumin in Parkinson disease (PD) is not well understood, our study will investigate the association between the serum albumin level and risk of dementia, motor impairment, as well as survival outcome in PD. Data were obtained from the publicly available dataset in the DRYAD database (https://datadryad.org/). The original prospective study enrolled patients with PD from a single center in Japan between March 2004 and November 2007. Due to missing values, 242 and 274 participants were included in the study, in which we aimed to, respectively, analyze the relationship between serum albumin and cognitive function as well as motor impairment; additionally, 264 participants were included to assess the association between baseline serum albumin levels and risk of PD-related death with a median follow-up of 5.24 years. Compared to patients of the low tertile of albumin levels, Mini-Mental State Examination (MMSE) of patients of middle tertile increased 2.09 [95% confidence interval (CI) (0.45, 3.73), P = .013], independent of age, sex, PD duration, modified Hoehn-Yahr (mHY) stage, C-reactive protein (CRP) level, and use of nonsteroidal anti-inflammatory drugs (NSAIDs). Further analysis revealed a positive curvilinear association between albumin and MMSE, with cutoff values of 3.9. As concentration serum albumin increased, the risk of severe motor impairment was grown [odds ratio (OR) 0.34 (95% CI 0.14,0.8), P = .013] after adjustment by age, sex, PD duration, MMSE scores, CRP level, and use of NSAIDs. Albumin levels increased per unit of mg/dL, and the risk of PD-related death reduced 0.74-fold with 95% CI (0.15, 0.86) (P = .021), independent of age, sex, PD disease duration, mHY stage, CRP levels, use of NSAIDs, and MMSE. Higher serum albumin levels were significantly association with the better cognitive function when albumin was <3.9 mg/dL, and played a protective role in severe motor impairment and PD-related death.

Blood-based biomarker in Parkinson's disease: potential for future applications in clinical research and practice

The clinical presentation of Parkinson's disease (PD) is both complex and heterogeneous, and its precise classification often requires an intensive work-up. The differential diagnosis, assessment of disease progression, evaluation of therapeutic responses, or identification of PD subtypes frequently remains uncertain from a clinical point of view. Various tissue- and fluid-based biomarkers are currently being investigated to improve the description of PD. From a clinician's perspective, signatures from blood that are relatively easy to obtain would have great potential for use in clinical practice if they fulfill the necessary requirements as PD biomarker. In this review article, we summarize the knowledge on blood-based PD biomarkers and present both a researcher's and a clinician's perspective on recent developments and potential future applications.

Association between levels of high-sensitivity C-reactive protein in plasma and freezing of gait in Parkinson's disease

This study explored the potential relationship between levels of high-sensitivity C-reactive protein (hs-CRP) in plasma and freezing of gait (FOG) in Parkinson's disease (PD) in China. A total of 72 healthy subjects, 62 PD patients with FOG, and 83 PD patients without FOG from our center were enrolled in this prospective study. Patients with FOG showed significantly higher hs-CRP levels than controls, but patients without FOG did not. Binary logistic regression analysis identified levels of hs-CRP in plasma to be an independent risk factor for FOG among the patients in our cohort (OR 6.371, 95% CI 2.589-15.678, p < 0.001). In fact, a cut-off level of 0.935 mg/L distinguished patients with or without FOG [area under the ROC curve (AUC) = 0.908, sensitivity 87.1%, specificity 89.2%]. Our study suggests that high levels of hs-CRP in plasma are associated with the occurrence of FOG in PD. The pooled data combined with a previous study carried out in Spain also indicate a positive association between plasma hs-CRP levels and FOG in PD. However, more research is still needed to verify the plasma hs-CRP as a potential biomarker of FOG.

Blood and Cerebrospinal Fluid Biomarkers of Inflammation in Parkinson's Disease

Given the clear role of inflammation in the pathogenesis of Parkinson's disease (PD) and its impact on incidence and phenotypical characteristics, this review provides an overview with focus on inflammatory biofluid markers in blood and cerebrospinal fluid (CSF) in PD patient cohorts. In preparation for clinical trials targeting the immune system, we specifically address the following questions: 1) What evidence do we have for pro-inflammatory profiles in blood and in CSF of sporadic and genetic PD patients? 2) Is there a role of anti-inflammatory mediators in blood/CSF? 3) Do inflammatory profiles in blood reflect those in CSF indicative of a cross-talk between periphery and brain? 4) Do blood/CSF inflammatory profiles change over the disease course as assessed in repeatedly taken biosamples? 5) Are blood/CSF inflammatory profiles associated with phenotypical trajectories in PD? 6) Are blood/CSF inflammatory profiles associated with CSF levels of neurodegenerative/PD-specific biomarkers? Knowledge on these questions will inform future strategies for patient stratification and cohort enrichment as well as suitable outcome measures for clinical trials.

Diagnostic AI Modeling and Pseudo Time Series Profiling of AD and PD Based on Individualized Serum Proteome Data

Background: Parkinson's disease (PD), Alzheimer's disease (AD) are common neurodegenerative disease, while mild cognitive impairment (MCI) may be happened in the early stage of AD or PD. Blood biomarkers are considered to be less invasive, less cost and more convenient, and there is tremendous potential for the diagnosis and prediction of neurodegenerative diseases. As a recently mentioned field, artificial intelligence (AI) is often applied in biology and shows excellent results. In this article, we use AI to model PD, AD, MCI data and analyze the possible connections between them. Method: Human blood protein microarray profiles including 156 CT, 50 MCI, 132 PD, 50 AD samples are collected from Gene Expression Omnibus (GEO). First, we used bioinformatics methods and feature engineering in machine learning to screen important features, constructed artificial neural network (ANN) classifier models based on these features to distinguish samples, and evaluated the model's performance with classification accuracy and Area Under Curve (AUC). Second, we used Ingenuity Pathway Analysis (IPA) methods to analyse the pathways and functions in early stage and late stage samples of different diseases, and potential targets for drug intervention by predicting upstream regulators. Result: We used different classifier to construct the model and finally found that ANN model would outperform the traditional machine learning model. In summary, three different classifiers were constructed to be used in different application scenarios, First, we incorporated 6 indicators, including EPHA2, MRPL19, SGK2, to build a diagnostic model for AD with a test set accuracy of up to 98.07%. Secondly, incorporated 15 indicators such as ERO1LB, FAM73B, IL1RN to build a diagnostic model for PD, with a test set accuracy of 97.05%. Then, 15 indicators such as XG, FGFR3 and CDC37 were incorporated to establish a four-category diagnostic model for both AD and PD, with a test set accuracy of 98.71%. All classifier models have an auc value greater than 0.95. Then, we verified that the constructed feature engineering filtered out fewer important features but contained more information, which helped to build a better model. In addition, by classifying the disease types more carefully into early and late stages of AD, MCI, and PD, respectively, we found that early PD may occur earlier than early MCI. Finally, there are 24 proteins that are both differentially expressed proteins and upstream regulators in the disease group versus the normal group, and these proteins may serve as potential therapeutic targets and targets for subsequent studies. Conclusion: The feature engineering we build allows better extraction of information while reducing the number of features, which may help in subsequent applications. Building a classifier based on blood protein profiles using deep learning methods can achieve better classification performance, and it can help us to diagnose the disease early. Overall, it is important for us to study neurodegenerative diseases from both diagnostic and interventional aspects.

Long non-coding RNA: An underlying bridge linking neuroinflammation and central nervous system diseases

Central nervous system (CNS) diseases are responsible for a large proportion of morbidity and mortality worldwide. CNS diseases caused by intrinsic and extrinsic stimuli stimulate the resident immune cells including microglia and astrocyte, resulting in neuroinflammation that exacerbates the progression of diseases. Recent evidence reveals the aberrant expression patterns of long non-coding RNAs (lncRNAs) in the damaged tissues following CNS diseases. It was also proposed that lncRNAs possessed immune-modulatory activities by directly or indirectly affecting various effector proteins including transcriptional factor, acetylase, protein kinase, phosphatase, etc. In addition, lncRNAs can form a sophisticated network by interacting with other molecules to regulate the expression or activation of downstream immune response pathways. However, the major roles of lncRNAs in CNS pathophysiologies are still elusive, especially in neuroinflammation. Herein, we tend to review some potential roles of lncRNAs in modulating neuroinflammation based on current evidence in various CNS diseases, in order to provide novel explanations for the initiation and progression of CNS diseases and help to establish therapeutic strategies targeting neuroinflammation.

Periphery and brain, innate and adaptive immunity in Parkinson's disease

Parkinson’s disease (PD) is a neurodegenerative disorder where alpha-synuclein plays a central role in the death and dysfunction of neurons, both, in central, as well as in the peripheral nervous system. Besides the neuronal events observed in patients, PD also includes a significant immune component. It is suggested that the PD-associated immune response will have consequences on neuronal health, thus opening immunomodulation as a potential therapeutic strategy in PD. The immune changes during the disease occur in the brain, involving microglia, but also in the periphery with changes in cells of the innate immune system, particularly monocytes, as well as those of adaptive immunity, such as T-cells. This realization arises from multiple patient studies, but also from data in animal models of the disease, providing strong evidence for innate and adaptive immune system crosstalk in the central nervous system and periphery in PD. Here we review the data showing that alpha-synuclein plays a crucial role in the activation of the innate and adaptive immune system. We will also describe the studies suggesting that inflammation in PD includes early changes in innate and adaptive immune cells that develop dynamically through time during disease, contributing to neuronal degeneration and symptomatology in patients. This novel finding has contributed to the definition of PD as a multisystem disease that should be approached in a more integratory manner rather than a brain-focused classical approach.

A simple-to-use web-based calculator for survival prediction in Parkinson's disease

Background: To establish and validate a nomogram and corresponding web-based calculator to predict the survival of patients with Parkinson’s disease (PD).

Methods: In this cohort study, we retrospectively evaluated patients (n=497) with PD using a two-stage design, from March 2004 to November 2007 and from July 2005 to July 2015. Predictive variables included in the model were identified by univariate and multiple Cox proportional hazard analyses in the training set.

Results: Independent prognostic factors including age, PD duration, and Hoehn and Yahr stage were determined and included in the model. The model showed good discrimination power with the area under the curve (AUC) values generated to predict 4-, 6-, and 8-year survival in the training set being 0.716, 0.783, and 0.814, respectively. In the validation set, the AUCs of 4- and 6-year survival predictions were 0.85 and 0.924, respectively. Calibration plots and decision curve analysis showed good model performance both in the training and validation sets. For convenient application, we established a web-based calculator (https://tangyl.shinyapps.io/PDprognosis/).

Conclusions: We developed a satisfactory, simple-to-use nomogram and corresponding web-based calculator based on three relevant factors to predict prognosis and survival of patients with PD. This model can aid personalized treatment and clinical decision-making.

Soluble CD163 Changes Indicate Monocyte Association With Cognitive Deficits in Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder with a significant immune component, as demonstrated by changes in immune biomarkers in patients' biofluids. However, which specific cells are responsible for those changes is unclear because most immune biomarkers can be produced by various cell types.

OBJECTIVES

The aim of this study was to explore monocyte involvement in PD.

METHODS

We investigated the monocyte-specific biomarker sCD163, the soluble form of the receptor CD163, in cerebrospinal fluid (CSF) and serum in two experiments, and compared it with other biomarkers and clinical data. Potential connections between CD163 and alpha-synuclein were studied in vitro.

RESULTS

CSF-sCD163 increased in late-stage PD and correlated with the PD biomarkers alpha-synuclein, Tau, and phosphorylated Tau, whereas it inversely correlated with the patients' cognitive scores, supporting monocyte involvement in neurodegeneration and cognition in PD. Serum-sCD163 increased only in female patients, suggesting a sex-distinctive monocyte response. CSF-sCD163 also correlated with molecules associated with adaptive and innate immune system activation and with immune cell recruitment to the brain. Serum-sCD163 correlated with proinflammatory cytokines and acute-phase proteins, suggesting a relation to chronic systemic inflammation. Our in vitro study showed that alpha-synuclein activates macrophages and induces shedding of sCD163, which in turn enhances alpha-synuclein uptake by myeloid cells, potentially participating in its clearance.

CONCLUSIONS

Our data present sCD163 as a potential cognition-related biomarker in PD and suggest a role for monocytes in both peripheral and brain immune responses. This may be directly related to alpha-synuclein's proinflammatory capacity but could also have consequences for alpha-synuclein processing. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Microorganisms that are related with increased risk for Parkinson's disease

Parkinson's disease is a neurodegenerative disorder that affects more than 7 million people worldwide. Its aetiology is unknown, although the hypothesis of a genetic susceptibility to environmental agents is accepted. These environmental agents include fungi, bacteria, and viruses. Three microorganisms are directly associated with a significantly increased risk of developing Parkinson's disease: the fungal genus Malassezia, the bacterium Helicobacter pylori, and the hepatitis C virus. If the host is vulnerable due to genetic susceptibility or immune weakness, these microorganisms can access and infect the nervous system, causing chronic neuroinflammation with neurodegeneration. Other microorganisms show an epidemiological association with the disease, including the influenza type A, Japanese encephalitis type B, St Louis, and West Nile viruses. These viruses can affect the nervous system, causing encephalitis, which can result in parkinsonism. This article reviews the role of all these microorganisms in Parkinson's disease.

Early-start vs delayed-start donepezil against cognitive decline in Parkinson disease: a randomized clinical trial

BACKGROUND

Cholinergic neurotransmission regulates neuroinflammation in Parkinson disease (PD).

RESEARCH DESIGN AND METHODS

The authors conducted a delayed-start study of donepezil for cognitive decline in non-demented PD patients. The study consisted of a 96-week randomized placebo-controlled double-blind phase 1, followed by a 24-week donepezil extension phase 2. The primary outcome measure was a change in the Mini-Mental State Examination (MMSE) at week 120.

RESULTS

A total of 98 patients were randomly allocated to the early-start (donepezil-to-donepezil) and delayed-start (placebo-to-donepezil) groups. Mean (SD) of the baseline MMSE was 27.6 (2.0) and 28.0 (2.1), respectively. MMSE change at week 120 was better in the early-start group than in the delayed-start group, but the difference was not significant. The MMSE declined in apolipoprotein ε4 carriers, but not in non-carriers, and the factor interaction (intervention × ε4 genotype) was highly significant (P < 0.001). Analyzed with the interaction, the difference was significant (group difference 1.95 [0.33 to 3.57], P = 0.018). The MMSE decline slope in phase 1 was significantly better in the early-start group than in the delayed-start group (P = 0.048).

CONCLUSIONS

Cognitive function deteriorated in ε4 carriers, but not in non-carriers, and early-start donepezil may postpone cognitive decline in the former.

Effects of advanced age and pituitary pars intermedia dysfunction on components of the acute phase reaction in horses

Age, neurodegenerative disorders, and dysfunction of insulin secretion may be correlated with increased systemic concentrations of acute phase markers. Thus, the study aimed to determine the effect of age, pituitary pars intermedia dysfunction (PPID), and insulin dysregulation (ID) associated with PPID, on markers of the acute phase reaction. Twenty-nine mix-breed horses of both sexes were classified into groups: (1) healthy adult controls, (2) healthy non-PPID geriatric horses, (3) PPID ID+ horses, and (4) PPID ID- horses. Whole blood proinflammatory cytokine gene expression and serum concentrations of pro- and anti-inflammatory cytokines and acute phase proteins were measured. The data were analyzed using the Mann-Whitney U-test, and correlations between groups of data were assessed using Spearman's correlation coefficient. The tests were statistically significant if P < 0.05. No differences in the whole blood cytokine gene expression, serum cytokine concentrations, or acute phase proteins were noted between the groups. In the PPID ID group, there was a strong correlation between the ACTH concentration after the administration of thyrotropin-releasing hormone and the expression of IL-8 (r = 0.941; P = 0.0321). In the PPID ID+ group, there was a strong correlation between basal insulin concentrations and serum amyloid A (SAA; r = 0.936; P = 0.0083) as well as between postprandial insulin concentrations and SAA (r = 0.965; P = 0.001). These data suggest that neurodegeneration in horses moderately affects circulating markers of inflammation and that ID in horses with PPID influences acute phase inflammatory markers.

Parkinson's Disease: A Comprehensive Analysis of Fungi and Bacteria in Brain Tissue

Parkinson's disease (PD) is characterized by motor disorders and the destruction of dopaminergic neurons in the substantia nigra pars compacta. In addition to motor disability, many patients with PD present a spectrum of clinical symptoms, including cognitive decline, psychiatric alterations, loss of smell and bladder dysfunction, among others. Neuroinflammation is one of the most salient features of PD, but the nature of the trigger remains unknown. A plausible mechanism to explain inflammation and the range of clinical symptoms in these patients is the presence of systemic microbial infection. Accordingly, the present study provides extensive evidence for the existence of mixed microbial infections in the central nervous system (CNS) of patients with PD. Assessment of CNS sections by immunohistochemistry using specific antibodies revealed the presence of both fungi and bacteria. Moreover, different regions of the CNS were positive for a variety of microbial morphologies, suggesting infection by a number of microorganisms. Identification of specific fungal and bacterial species in different CNS regions from six PD patients was accomplished using nested PCR analysis and next-generation sequencing, providing compelling evidence of polymicrobial infections in the CNS of PD. Most of the fungal species identified belong to the genera Botrytis, Candida, Fusarium and Malassezia. Some relevant bacterial genera were Streptococcus and Pseudomonas, with most bacterial species belonging to the phyla Actinobacteria and Proteobacteria. Interestingly, we noted similarities and differences between the microbiota present in the CNS of patients with PD and that in other neurodegenerative diseases. Overall, our observations lend strong support to the concept that mixed microbial infections contribute to or are a risk factor for the neuropathology of PD. Importantly, these results provide the basis for effective treatments of this disease using already approved and safe antimicrobial therapeutics.

Salsolinol-neurotoxic or Neuroprotective?

Salsolinol (6,7-dihydroxy-1-methyl-1,2,3,4-tetrahydroisoquinoline), widely available in many edibles, is considered to alter the function of dopaminergic neurons in the central nervous system and thus, multiple hypotheses on its either physiological and/or pathophysiological role have emerged. The aim of our work was to revisit its potentially neurotoxic and/or neuroprotective role through a series of both in vitro and in vivo experiments. Salsolinol in the concentration range 10-250 μM did not show any significant release of lactate dehydrogenase from necrotic SH-SY5Y cells and was able in the concentration of 50 and 100 μM to rescue SH-SY5Y cells from death induced by H₂O₂. Its neuroprotective effect against neurotoxin 6-hydroxydopamine was also determined. Salsolinol was found to decrease significantly the reactive oxygen species level in SH-SY5Y cells treated by 500 μM H₂O₂ and the caspase activity induced by 300 μM of H₂O₂ or 100 μM of 6-hydroxydopamine. Serum levels of TNFα and CRP of salsolinol-treated rats were not significantly different from control animals. Both TNFα and CRP served as indirect markers of neurotoxicity and/or neuroprotection. Although the neurotoxic properties of salsolinol have numerously been emphasized, its neuroprotective properties should not be neglected and need greater consideration.

High ultrasensitive serum C-reactive protein may be related to freezing of gait in Parkinson's disease patients

C-reactive protein (CRP) is a biomarker of systemic inflammation that has been linked to accelerated decline in walking speed in older adults. The aim of the present study was to compare the CRP levels of PD patients with vs patients without freezing of gait (FOG). Patients and controls participating in the COPPADIS-2015 study that performed blood extraction for determining molecular serum biomarkers were included. Patients with FOG were identified as those with a score of 1 or greater on item-3 of the Freezing of Gait Questionnaire (FOG-Q). Immunoassay was used for determining ultrasensitive CRP (US-CRP) level (mg/dL). In the PD group (n = 225; 61.8 ± 9.5 years old, 61.8% males), 32% of the patients presented FOG but none in the control group (n = 65; 60.3 ± 6.1 years old, 56.9% males) (p < 0.0001). Differences in US-CRP level were significant in patients with FOG vs patients without FOG and vs controls (0.31 ± 0.52 vs 0.16 ± 0.21 vs 0.21 ± 0.22; p = 0.04). Significant differences were also observed between patients with vs without FOG (p = 0.001) but not between patients and controls (p = 0.163). US-CRP level was related to FOG (OR = 4.369; 95% CI 1.105-17.275; p = 0.036) along with H&Y (OR = 2.974; 95% CI 1.113-7.943; p = 0.030) and non-motor symptoms burden (NMSS total score; OR = 1.017; 95% CI 1.005-1.029; p = 0.006) after adjusting for age, gender, disease duration, equivalent daily levodopa dose, number of non-antiparkinsonian drugs per day, motor fluctuations, cognition, motor phenotype, and chronic use of anti-inflammatory drugs. The present study suggests that serum US-CRP level is related to FOG in PD patients. Inflammation could be linked to FOG development.

Cerebrospinal fluid biomarker for Parkinson's disease: An overview

In Parkinson's disease (PD), there is a wide field of recent and ongoing search for useful biomarkers for early and differential diagnosis, disease monitoring or subtype characterization. Up to now, no biofluid biomarker has entered the daily clinical routine. Cerebrospinal fluid (CSF) is often used as a source for biomarker development in different neurological disorders because it reflects changes in central-nervous system homeostasis. This review article gives an overview about different biomarker approaches in PD, mainly focusing on CSF analyses. Current state and future perspectives regarding classical protein markers like alpha‑synuclein, but also different "omics" techniques are described. In conclusion, technical advancements in the field already yielded promising results, but further multicenter trials with well-defined cohorts, standardized protocols and integrated data analysis of different modalities are needed before successful translation into routine clinical application.

Risk factors for complications and mortality of percutaneous endoscopic gastrostomy insertion

BACKGROUND

Percutaneous endoscopic gastrostomy (PEG) is a relatively safe procedure; however, acute and chronic complications of PEG have been reported. We aimed to determine risk factors associated with complications and 30-day mortality after PEG, based on 11 years of experience at a single tertiary hospital.

METHODS

In total, 401 patients who underwent first PEG insertion at the Asan Medical Center, Seoul, Korea, between January 2005 and December 2015 were eligible. Medical records were retrospectively reviewed to determine clinical characteristics and outcomes of 139 and 262 patients who underwent pull-type and introducer-type PEG, respectively.

RESULTS

The median age of the overall population was 68 years, and the median body mass index was 19.5 kg/m2. Acute and chronic complications developed in 96 (23.9%) and 105 (26.2%) patients. Acute ileus and chronic tube obstruction were significantly more frequent in the introducer-type PEG group (p = 0.033 and 0.001, respectively). The 30-day mortality rate was 5.0% (median survival: 10.5 days). Multivariate analysis revealed that underlying malignancy was a predictor of acute complications; age ≥ 70 years and diabetes mellitus were predictors of chronic complications. The median follow-up was 354 days. Neurologic disease and malignancy were the most common indications for PEG. Neurologic diseases were classified into two groups: stroke and the other neurologic disease group (including dementia, Parkinson's disease, neuromuscular disease, and hypoxic brain damage). Multivariate analysis showed that 30-day mortality was significantly lower in the other neurologic disease group and higher in patients with platelet count < 100,000/μL, and C-reactive protein (CRP) ≥ 5 mg/dL.

CONCLUSIONS

PEG is a relatively safe and feasible procedure, but it was associated with significantly higher early mortality rate in patients with platelet count < 100,000/μL or CPR≥5mg/dL, and lower early mortality rate in neurologic disease group including dementia, Parkinson's disase, neuromuscular disease, and hypoxic brain damage. In addition, acute complications in patients with underlying malignancy, and chronic complications in patients aged ≥70 and those with diabetes mellitus should be considered during and after PEG.

The Clinical Significance and Potential Role of C-Reactive Protein in Chronic Inflammatory and Neurodegenerative Diseases

C-reactive protein (CRP) is an acute-phase protein synthesized by hepatocytes in response to pro-inflammatory cytokines during inflammatory/infectious processes. CRP exists in conformationally distinct forms such as the native pentameric CRP and monomeric CRP (mCRP) and may bind to distinct receptors and lipid rafts and exhibit different functional properties. It is known as a biomarker of acute inflammation, but many large-scale prospective studies demonstrate that CRP is also known to be associated with chronic inflammation. This review is focused on discussing the clinical significance of CRP in chronic inflammatory and neurodegenerative diseases, such as cardiovascular disease, type 2 diabetes mellitus, age-related macular degeneration, hemorrhagic stroke, Alzheimer’s disease, and Parkinson’s disease, including recent advances on the implication of CRP and its forms specifically on the pathogenesis of these diseases. Overall, we highlight the advances in these areas that may be translated into promising measures for the diagnosis and treatment of inflammatory diseases.

A review of drug therapy for sporadic fatal insomnia

BACKGROUND

Sporadic fatal insomnia (sFI) is a rapid progressive neurodegenerative disease characterised by gradual to perpetual insomnia, followed by dysautonomia, coma and death. ¹ The cause of sFI was recently mapped to a mutation in a protein, the prion, found in the human brain. It is the unfolding of the prion that leads to the generation of toxic oligomers that destroy brain tissue and function. Recent studies have confirmed that a methionine mutation at codon 129 of the human Prion is characteristic of sFI. Current treatment slows down the progression of the disease, but no cure has been found, yet.

METHODS

We used Molecular Docking and Molecular Dynamics simulation methods, to study the toxic Fatal-Insomnia-prion conformations at local unfolding. The idea was to determine these sites and to stabilise these regions against unfolding and miss-folding, using a small ligand, based on a phenothiazine "moiety".

CONCLUSION

As a result we here discuss current fatal insomnia therapy and present seven novel possible compounds for in vitro and in vivo screening.

Candidate inflammatory biomarkers display unique relationships with alpha-synuclein and correlate with measures of disease severity in subjects with Parkinson's disease

Background

Efforts to identify fluid biomarkers of Parkinson’s disease (PD) have intensified in the last decade. As the role of inflammation in PD pathophysiology becomes increasingly recognized, investigators aim to define inflammatory signatures to help elucidate underlying mechanisms of disease pathogenesis and aid in identification of patients with inflammatory endophenotypes that could benefit from immunomodulatory interventions. However, discordant results in the literature and a lack of information regarding the stability of inflammatory factors over a 24-h period have hampered progress.

Methods

Here, we measured inflammatory proteins in serum and CSF of a small cohort of PD (n = 12) and age-matched healthy control (HC) subjects (n = 6) at 11 time points across 24 h to (1) identify potential diurnal variation, (2) reveal differences in PD vs HC, and (3) to correlate with CSF levels of amyloid β (Aβ) and α-synuclein in an effort to generate data-driven hypotheses regarding candidate biomarkers of PD.

Results

Despite significant variability in other factors, a repeated measures two-way analysis of variance by time and disease state for each analyte revealed that serum IFNγ, TNF, and neutrophil gelatinase-associated lipocalin (NGAL) were stable across 24 h and different between HC and PD. Regression analysis revealed that C-reactive protein (CRP) was the only factor with a strong linear relationship between CSF and serum. PD and HC subjects showed significantly different relationships between CSF Aβ proteins and α-synuclein and specific inflammatory factors, and CSF IFNγ and serum IL-8 positively correlated with clinical measures of PD. Finally, linear discriminant analysis revealed that serum TNF and CSF α-synuclein discriminated between PD and HC with a minimum of 82% sensitivity and 83% specificity.

Conclusions

Our findings identify a panel of inflammatory factors in serum and CSF that can be reliably measured, distinguish between PD and HC, and monitor inflammation as disease progresses or in response to interventional therapies. This panel may aid in generating hypotheses and feasible experimental designs towards identifying biomarkers of neurodegenerative disease by focusing on analytes that remain stable regardless of time of sample collection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-017-0935-1) contains supplementary material, which is available to authorized users.

Serum C-Reactive Protein as a Prognostic Biomarker in Amyotrophic Lateral Sclerosis

Importance

Various factors have been proposed as possible candidates associated with the prognosis of amyotrophic lateral sclerosis (ALS); however, there is still no consensus on which biomarkers are reliable prognostic factors. C-reactive protein (CRP) is a biomarker of the inflammatory response that shows significant prognostic value for several diseases.

Objective

To examine the prognostic significance of CRP in ALS.

Design, Setting, and Participants

Patients' serum CRP levels were evaluated from January 1, 2009, to June 30, 2015, in a large cohort of patients with ALS observed by an Italian tertiary multidisciplinary center. Results were replicated in an independent cohort obtained from a population-based registry of patients with ALS. A post hoc analysis was performed of the phase 2 trial of NP001 to determine whether stratification by levels of CRP improves differentiation of responders and nonresponders to the drug.

Main Outcomes and Measures

Serum CRP levels from the first examination were recorded to assess their effect on disease progression and survival.

Results

A total of 394 patients with ALS (168 women and 226 men; mean [SD] age at diagnosis, 60.18 [13.60] years) were observed in a tertiary multidisciplinary center, and the analysis was replicated in an independent cohort of 116 patients with ALS (50 women and 66 men; mean [SD] age at diagnosis, 67.00 [10.74] years) identified through a regional population-based registry. Serum CRP levels in the 394 patients with ALS correlated with severity of functional impairment, as measured by total score on the ALS Functional Rating Scale-Revised, at first evaluation (r = -0.14818; P = .004), and with patient survival (hazard ratio, 1.129; 95% CI, 1.033-1.234; P = .007). Similar results were found in the independent cohort (hazard ratio, 1.044; 95% CI, 1.016-1.056; P ≤ .001). Moreover, a post hoc analysis of the phase 2 trial of NP001 using the same CRP threshold showed that patients with elevated baseline CRP levels receiving the higher dose of NP001 had significantly less functional impairment after the treatment period compared with patients with normal baseline CRP, regardless of whether patients with normal CRP levels received NP001 or placebo (3.00 [3.62] vs -7.31 [6.23]; P = .04).

Conclusions and Relevance

These findings suggest that patients with ALS and elevated serum CRP levels progress more rapidly than do those with lower CRP levels and that this elevation may reflect a neuroinflammatory state potentially responsive to the immune regulators such as NP001.

Inflammation-driven malnutrition: a new screening tool predicts outcome in Crohn's disease

Malnutrition is a frequent feature in Crohn's disease (CD), affects patient outcome and must be recognised. For chronic inflammatory diseases, recent guidelines recommend the development of combined malnutrition and inflammation risk scores. We aimed to design and evaluate a new screening tool that combines both malnutrition and inflammation parameters that might help predict clinical outcome. In a prospective cohort study, we examined fifty-five patients with CD in remission (Crohn's disease activity index (CDAI) <200) at 0 and 6 months. We assessed disease activity (CDAI, Harvey-Bradshaw index), inflammation (C-reactive protein (CRP), faecal calprotectin (FC)), malnutrition (BMI, subjective global assessment (SGA), serum albumin, handgrip strength), body composition (bioelectrical impedance analysis) and administered the newly developed 'Malnutrition Inflammation Risk Tool' (MIRT; containing BMI, unintentional weight loss over 3 months and CRP). All parameters were evaluated regarding their ability to predict disease outcome prospectively at 6 months. At baseline, more than one-third of patients showed elevated inflammatory markers despite clinical remission (36·4 % CRP ≥5 mg/l, 41·5 % FC ≥100 µg/g). Prevalence of malnutrition at baseline according to BMI, SGA and serum albumin was 2-16 %. At 6 months, MIRT significantly predicted outcome in numerous nutritional and clinical parameters (SGA, CD-related flares, hospitalisations and surgeries). In contrast, SGA, handgrip strength, BMI, albumin and body composition had no influence on the clinical course. The newly developed MIRT was found to reliably predict clinical outcome in CD patients. This screening tool might be used to facilitate clinical decision making, including treatment of both inflammation and malnutrition in order to prevent complications.

Increased Risk of Parkinson's Disease in Patients With Obstructive Sleep Apnea: A Population-Based, Propensity Score-Matched, Longitudinal Follow-Up Study

Obstructive sleep apnea (OSA), characterized by repetitive episodes of apnea/hypopnea and hypoxia, is associated with systemic inflammation and induces metabolic, endocrine, and cardiovascular diseases. Inflammation might have an impact on neurodegenerative diseases. This study investigates the possible association between OSA and Parkinson's disease (PD). Random samples out of 1 million individuals were collected from Taiwan's National Health Insurance database. A total of 16,730 patients with newly diagnosed OSA from 2002 to 2008 were recruited and compared with a cohort of 16,730 patients without OSA matched for age, gender, and comorbidities using propensity scoring. All patients were tracked until a diagnosis of PD, death, or the end of 2011.During the mean 5.6-year follow-up period, the incidence rates of PD were 2.30 per 1000 person-years in the OSA cohort and 1.71per 1000 person-years in the comparison group. The incidence rate ratio (IRR) for PD was greater in older patients (≧ 65 years) and male patients with OSA than the controls, respective IRRs being 1.34 and 1.47. After adjustment for the comorbidities, patients with OSA were 1.37 times more likely to have PD than patients without (95% CI = 1.12-1.68, P < 0.05). Subgroup analysis showed that older patients and patients with coronary artery disease, stroke, or chronic kidney disease had a higher risk for PD than their counter parts. Log-rank analysis revealed that patients with OSA had significantly higher cumulative incidence rates of PD than the comparison group (P = 0.0048). Patients with OSA are at an increased risk for subsequent PD, especially elderly male patients.