Introduction:We sought to cross-validate our previously published blood test for detecting Dementia with Lewy Bodies (DLB). Method:Plasma samples were analyzed on 428 individuals (DLB n=89, Parkinson's Disease (PD) without dementia n=126, Alzheimer's Disease (AD) n=108, Normal Controls (NC) n=105). Results:The proteomic profile discriminated DLB and PD from NC with an AUC (Area Under the Curve) of 0.96 with demographics of age, sex and education. The proteomic profile also distinguished DLB from the PD group with an AUC of 0.92 with demographics. It further distinguished DLB, PD and AD from NC with an AUC of 0.95 as well as DLB from AD with an AUC of 0.92 with demographics. Discussion:This data provides additional evidence of the potential utility of a multi-tiered blood-based proteomic screening method for detecting DLB and distinguishing DLB from NC, PD and AD that can be implemented in primary care settings to aid in the referral process.
Background: A blood-test that could serve as a potential first step in a multi-tiered neurodiagnostic process for ruling out Parkinson’s disease (PD) in primary care settings would be of tremendous value. This study therefore sought to conduct a large-scale cross-validation of our Parkinson’s disease Blood Test (PDBT) for use in primary care settings. Methods: Serum samples were analyzed from 846 PD and 2291 volunteer controls. Proteomic assays were run on a multiplex biomarker assay platform using Electrochemiluminescence (ECL). Diagnostic accuracy statistics were generated using area under the receiver operating characteristic curve (AUC), Sensitivity (SN), Specificity (SP) and Negative Predictive Value (NPV). Results: In the training set, the PDBT reached an AUC of 0.98 when distinguishing PD cases from controls with a SN of 0.84 and SP of 0.98. When applied to the test set, the PDBT yielded an AUC of 0.96, SN of 0.79 and SP of 0.97. The PDBT obtained a negative predictive value of 99% for a 2% base rate. Conclusion: The PDBT was highly successful in discriminating PD patients from control cases and has great potential for providing primary care providers with a rapid, scalable and cost-effective tool for screening out PD.
Background:There is no any large randomized clinical trial of antihypertensive drug treatment with 18-year passive follow-up to examine the risk of Alzheimer's Disease (AD) or Related Dementias (ADRD).Methods:Post-trial passive follow-up study of Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants in 1994-1998 by linking with their Medicare claims data through 2017 among 17,158 subjects in 567 U.S. centers who were free of ADRD at baseline on January 1, 1999. Main outcome was the occurrence of ADRD over 18 years of follow-up.Results:The 18-year cumulative incidence rates were 30.9% for AD, 59.2% for non-AD dementias, and 60.9% for any ADRD. The 18-year cumulative incidence of AD was almost identical for the 3 drug groups (30.5% for chlorthalidone, 31.1% for amlodipine, and 31.4% for lisinopril). The hazard ratios of AD, non-AD dementias and total ADRD were not statistically significantly different among the 3 drug groups. The adjusted hazard ratio of AD was 1.04 (95% CI: 0.94-1.14) for chlorthalidone versus amlodipine, 1.02 (0.92-1.13) for lisinopril versus amlodipine, and 0.98 (0.89-1.08) for lisinopril versus chlorthalidone, which were not significantly different. The risk of AD and non-AD dementias was significantly higher in older subjects, females, blacks, non-Hispanics, subjects with lower education, and subjects with vascular diseases.Conclusion:The risk of ADRD did not vary significantly by 3 antihypertensive drugs in ALLHAT trial participants with 18-years of follow-up. The risk of ADRD was significantly associated with age, gender, race/ethnicity, education, and history of vascular diseases.
We report a case of a patient with mixed dementia successfully treated with a personalized multimodal therapy. Monotherapeutics are inadequate for the treatment of Alzheimer's disease (AD) and mixed dementia; therefore, we approach treatment through an adaptive personalized multimodal program. Many multimodal programs are pre-determined, and thus may not address the underlying contributors to cognitive decline in each particular individual. The combination of a targeted, personalized, precision medicine approach using a multimodal program promises advantages over monotherapies and untargeted multimodal therapies for multifactorial dementia. In this case study, we describe successful treatment for a patient diagnosed with AD, using a multimodal, programmatic, precision medicine intervention encompassing therapies targeting multiple dementia diastheses. We describe specific interventions used in this case that are derived from a comprehensive protocol for AD precision medicine. After treatment, our patient demonstrated improvements in quantitative neuropsychological testing, volumetric neuroimaging, PET scans, and serum chemistries, accompanied by symptomatic improvement over a 3.5-year period. This case outcome supports the need for rigorous trials of comprehensive, targeted combination therapies to stabilize, restore, and prevent cognitive decline in individuals with potentially many underlying causes of such decline and dementia. Our multimodal therapy included personalized treatments to address each potential perturbation to neuroplasticity. In particular, neuroinflammation and metabolic subsystems influence cognitive function and hippocampal volume. In this patient with a primary biliary cholangitis (PBC) multimorbidity component, we introduced a personalized diet that helped reduce liver inflammation. Together, all these components of multimodal therapy showed a sustained functional and cognitive benefit. Multimodal therapies may have systemwide benefits on all dementias, particularly in the context of multimorbidity. Furthermore, these therapies provide generalized health benefits, as many of the factors - such as inflammation - that impact cognitive function also impact other systems.
Coronavirus disease of the year 2019 (COVID-19) is categorized as an acute, rapid onset viral pneumonia caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is a member of the Betacoronavirus genus in the family Coronaviridae closely related to the severe acute respiratory syndrome coronavirus (SARS CoV) and the Middle East Respiratory Syndrome coronavirus (MERS-CoV). Of all coronaviruses SARS-CoV-2 has emerged as an exceedingly pathogenic, highly transmissible lethal virus currently causing a serious pandemic of global proportions. The World Health Organization (WHO) reports that there are currently about ~141 million cases of COVID-19 in 219 countries along with about ~3.1 million total deaths as of mid-April 2021 [1-3]. SARS-CoV-2 mainly infects surface epithelial cells of the alveoli located in the lower respiratory tract of humans, causing acute lung injury, severe pneumonia and acute respiratory distress syndrome resulting in high morbidity and mortality. However due to the ubiquity of the ACE2 receptor many other cell and tissue types and physiological systems are also involved in COVID-19 infection, and this may in part explain the extensive variety of the signs and symptoms observed in COVID-19 patients [3]. Interestingly, the zoonotic emergence of SARS-CoV-2 and the role of intermediate hosts such as old world fruit bats (Pteropus scapulatus) are considered one of the major natural mammalian repositories of SARS-CoV-2 and the probable source of interspecies transmission [4-7].
The human gastrointestinal (GI)-tract microbiome is a rich, complex and dynamic source of microorganisms that possess a staggering diversity and complexity. Importantly there is a significant variability in microbial complexity even amongst healthy individuals-this has made it difficult to link specific microbial abundance patterns with age-related neurological disease. GI-tract commensal microorganisms are generally beneficial to human metabolism and immunity, however enterotoxigenic forms of microbes possess significant potential to secrete what are amongst the most neurotoxic and pro-inflammatory biopolymers known. These include toxic glycolipids such as lipopolysaccharide (LPS), enterotoxins, microbial-derived amyloids and small non-coding RNA. One major microbial species of the GI-tract microbiome, about ~100-fold more abundant than Escherichia coli in deep GI-tract regions is Bacteroides fragilis, an anaerobic, rod-shaped Gram-negative bacterium. B. fragilis can secrete: (i) a particularly potent, pro-inflammatory and unique LPS subtype (BF-LPS); and (ii) a zinc-metalloproteinase known as B. fragilis-toxin (BFT) or fragilysin. Ongoing studies indicate that BF-LPS and/or BFT disrupt paracellular-and transcellular-barriers by cleavage of intercellular-proteins resulting in ‘leaky’ barriers. These barriers: (i) become defective and more penetrable with aging and disease; and (ii) permit entry of microbiome-derived neurotoxins into the systemic-circulation from which they next transit the blood-brain barrier and gain access to the CNS. Here LPS accumulates and significantly alters homeostatic patterns of gene expression. The affinity of LPS for neuronal nuclei is significantly enhanced in the presence of amyloid beta 42 (Aβ42) peptides. Recent research on the appearance of the brain thanatomicrobiome at the time of death and the increasing likelihood of a complex brain microbiome are reviewed and discussed. This paper will also highlight some recent advances in this extraordinary research area that links the pro-inflammatory exudates of the GI-tract microbiome with innate-immune disturbances and inflammatory-signaling within the CNS with reference to Alzheimer’s disease (AD) wherever possible.
BACKGROUND:Alzheimer's Disease (AD) is a neurodegenerative complex brain disease that represents a public health concern. AD is considered the fifth leading cause of death in Americans who are older than 65 years which prioritizes the importance of understanding the etiology of AD in its early stages before the onset of symptoms. This study attempted to further understand Alzheimer's disease (AD) etiology by investigating the dysregulated genes using gene expression data from multiple brain regions.METHODS:A linear mixed-effects model for differential gene expression analysis was used in a sample of 15 AD and 30 control subjects, each with data from four different brain regions, in order to deal with the hierarchical multilevel data. Post-hoc Gene Ontology and pathway enrichment analyses provided insights on the biological implications in AD progression. Supervised machine learning algorithms were used to assess the discriminative power of the top 10 candidate genes in distinguishing between the two groups.RESULTS:Enrichment analyses revealed biological processes and pathways that are related to structural constituents and organization of the axons and synapses. These biological processes and pathways imply dysfunctional axon and synaptic transmission between neuronal cells in AD. Random Forest classification algorithm gave the best accuracy on the test data with F1-score of 0.88.CONCLUSION:The differentially expressed genes were associated with axon and synaptic transmissions which affect the neuronal connectivity in cognitive systems involved in AD pathophysiology. These genes may open ways to explore new effective treatments and early diagnosis before the onset of clinical symptoms.
Objectives: With an estimated seven to ten million sufferers worldwide, Parkinson’s disease (PD) is the second most common age-related neurodegenerative disorder. Progress in elucidating its causes has been slow, partly due to the lack of human-relevant models. Similarly, while the contribution of iron is increasingly advocated, identifying its role in disease progression remains challenging mainly due to the lack of valid model. In this study, we created Parkinson-like conditions in a human neuron model and conducted preliminary studies on iron-related parameters to assess whether these cells replicated iron accumulation observed in Parkinsonism. Methods: ReNcell VM (human neural progenitor) were differentiated into dopaminergic neurons (dDCNs) and treated with neurotoxin 6-hydroxy dopamine (100 μM) to mimic Parkinsonism. Total intracellular, mitochondrial and cytoplasmic iron was measured by ferrozine assay. Expression of iron-related genes TFRC, SLC40A1, HAMP and SLC25A37 were assessed through real-time PCR. Results: Data showed that the treated dDCNs accumulated iron over time and exceeded levels measured in untreated dDCNs by 2.5-fold at 48 h (p<0.02). Following the treatment, the treated cells showed lower expression of TFRC (p<0.05), but substantially higher mRNA expressions of SLC40A1 (9-fold; p<0.02) and HAMP (5.7-fold; p<0.05), along with higher intracellular iron (p<0.05). Higher iron accumulation in the mitochondria than cytosol (p<0.05), was also observed with increased expression of the mitochondrial iron-importer SLC25A37 (p=0.08). Conclusion: Our Parkinsonian model demonstrates iron accumulation and elevated HAMP expression as previously described in PD phenotype. The observed mitochondrial iron shuttling, which is proposed to be one of the primary contributors of oxidative stress in PD, calls for further investigation. The differences observed in distribution of iron in our human model and with the expression of major iron-related proteins, indicate that our model reproduces the disease state successfully, and suggests that further study could help in advancing our understanding of PD.
Alzheimer's Disease (AD) is a chronic neurodegenerative disease that affects over 5 million individuals in the United States alone. Currently, there are only two kinds of pharmacological interventions available for symptomatic relief of AD; Acetyl Cholinesterase Inhibitors (AChEI) and N-methyl-D-aspartic Acid (NMDA) receptor antagonists and these drugs do not slow down or stop the progression of the disease. Several molecular targets have been implicated in the pathophysiology of AD, such as the tau (τ) protein, Amyloid-beta (Aβ), the Amyloid Precursor Protein (APP) and more and several responses have also been observed in the advancement of the disease, such as reduced neurogenesis, neuroinflammation, oxidative stress and iron overload. In this review, we discuss general features of AD and several small molecules across different experimental AD drug classes that have been studied for their effects in the context of the molecular targets and responses associated with the AD progression. These drugs include: Paroxetine, Desferrioxamine (DFO), N-acetylcysteine (NAC), Posiphen/-(-)Phenserine, JTR-009, Carvedilol, LY450139, Intravenous immunoglobulin G 10%, Indomethacin and Lithium Carbonate (Li2CO3).
There is a known relationship between Alzheimer's disease (AD) and Down syndrome (DS), with the latter typically developing AD-like neuropathology in mid-life. In order to further understand this relationship we examined intersectin-1 (ITSN1) and the regulator of calcineurin-1 (RCAN1), proteins involved in endosomal and lysosomal trafficking that are over-expressed in DS. We examined RCAN1 and ITSN1 levels (both long (-L) and short (-S) isoforms) and the level of endogenous metals in White Blood Cells (WBCs) collected from AD patients who were enrolled in the Australian Imaging, Biomarker and Lifestyle Study on Ageing (AIBL). We also examined RCAN1 and ITSN1-S and -L in post-mortem brain tissue in a separate cohort of patients with AD or other types of dementia including Dementia with Lewy Bodies (DLB) and non-Alzheimer's disease dementia. We found that RCAN1 was significantly elevated in AD and DLB brain compared with controls, but there was no difference in the level of RCAN1 in WBCs of AD patients. There were no differences in the levels of ITSN1-L and -S between AD and the control, nor between other types of dementia and the control. We found that there were no differences in the levels of metals between AD and the control WBCs. In conclusion, our data demonstrate that RCAN1 is differentially regulated between the peripheral and central compartments in AD and should be further investigated to understand its potential role in dementia of AD and DLB.
BACKGROUND:Alzheimer's disease (AD) is the most common form of senile dementia. However, its pathological mechanisms are not fully understood. In order to comprehend AD pathological mechanisms, researchers employed AD-related DNA microarray data and diverse computational algorithms. More efficient computational algorithms are needed to process DNA microarray data for identifying AD-related candidate genes.METHODS:In this paper, we propose a specific algorithm that is based on the following observation: When an acrobat walks along a steel-wire, his/her body must have some swing; if the swing can be controlled, then the acrobat can maintain the body balance. Otherwise, the acrobat will fall. Based on this simple idea, we have designed a simple, yet practical, algorithm termed as the Amplitude Deviation Algorithm (ADA). Deviation, overall deviation, deviation amplitude, and 3δ are introduced to characterize ADA.RESULTS:52 candidate genes for AD have been identified via ADA. The implications for some of the AD candidate genes in AD pathogenesis have been discussed.CONCLUSIONS:Through the analysis of these AD candidate genes, we believe that AD pathogenesis may be related to the abnormality of signal transduction (AGTR1 and PTAFR), the decrease in protein transport capacity (COL5A2 (221729_at), COL5A2 (221730_at), COL4A1), the impairment of axon repair (CNR1), and the intracellular calcium dyshomeostasis (CACNB2, CACNA1E). However, their potential implication for AD pathology should be further validated by wet lab experiments as they were only identified by computation using ADA.
Objective: Aging hampers visual function in a multifactorial manner and the underlying perceptual deficits cannot be explained by anatomical alterations of the eye and/or visual cortex alone. The aging process of structures of the Ascending Visual Pathway (AVP) between neuroretina and visual cortex is rarely studied. The age-related increase of Beta-Synuclein (SNCB) was detected in both the neuroretina and the visual cortex (V1) in different species. SNCB acts as a physiological antagonist to neurodegenerative disease -associated alpha-synuclein. The aim of the work was to explore expression patterns of SNCB within different parts of the AVP. Further, the role of SNCB in different targeted neuronal tissues was studied. Methods: The expressions of SNCB were compared in the newborn, juvenile, adult, and aged Optic Chiasm (OC), Tracuts Opticus (TO), Laterale Geniculate Nucleus (LGN), and superior colliculus (LGN) of rats. Western blot (WB), quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and immunohistochemistry (IHC) analyses were employed to determine whether the changes identified by proteomics were verifiable at the cellular and molecular levels. To investigate the properties of SNCB in neuronal and glial cells, rat retinal and cortical samples (P5-7) were prepared and exposed to different SNCB concentrations up to 72 h in-vitro. The suspected influence on the expression on neuronal cells (e.g., beta III tubulin) and glial cell (e.g., glial fibrillary acidic protein) as well as apoptosis markers (e.g., TUNEL) was assessed by IHC, WB, and qRT-PCR. In addition, the p53-MDM2 signalling pathway was studied by IHC. Results: An increase of SNCB expression was detected in all examined regions of the AVP. Main differences of SNCB expression regarding to associated cell types were found in OC and TO in comparison to LGN and SC. The detected protein alterations in OC and TO were analogous to recent reports of the retinal profiles, while the SNCB expression characteristics in LGN and SC were more comparable to the characteristics within cortical tissues. Differences in response to SCNB exposure were found between retinal and cortical cells in-vitro. A loss of neuronal cells together with an increased apoptosis has been found in retinal cultures. In contrast, cortical cells show a beneficial elevation of neuronal response after SNCB exposure. While SNCB-exposed neuroretina show an activation of the p53-MDM-2 signaling, a decreased activation of p53-MDM-2 singanling pathway in cortical cells has been found. Conclusions: This study is the first to provide evidence that SNCB expression is associated with postnatal maturation and aging in the AVP of rats. Moreover, SNCB may exert different effects on several cell subtypes within selected neuronal targets like neuroretina and cortex. The findings may indicate the role of SNCB in key functional pathways and may account for the onset and/or progression of age-related pathologies. Further studies are needed to derive an increased understanding of neurodegenerative diseases of the retina and the cortex.
The hippocampus has been a primary region of study with regards to synaptic and functional changes in Alzheimer’s disease (AD) due to its involvement in early stages, specifically area CA1. However, most work in this area has treated CA1 as a homogeneous structure comprised of uniform neural circuits. Yet, there is a plethora of evidence that CA1 varies in its structure and function across anatomical axes. Here I review the heterogeneity of the functional and circuit architecture of hippocampal area CA1 across three primary anatomical axes. I also summarize evidence that AD differentially affects these subregions, as well as hypotheses as to why this may occur.
Despite a wealth of knowledge gained in the past three decades concerning the molecular underpinnings of Alzheimer's disease (AD), progress towards obtaining effective, disease modifying therapies has proven to be challenging. In this manner, numerous clinical trials targeting the production, aggregation, and toxicity of beta-amyloid, have failed to meet efficacy standards. This puts into question the beta-amyloid hypothesis and suggests that additional treatment strategies should be explored. The recent emergence of CRISPR/Cas9 gene editing as a relatively straightforward, inexpensive, and precise system has led to an increased interest of applying this technique in AD. CRISPR/Cas9 gene editing can be used as a direct treatment approach or to help establish better animal models that more faithfully mimic human neurodegenerative diseases. In this manner, this technique has already shown promise in other neurological disorders, such as Huntington's disease. The purpose of this review is to examine the potential utility of CRISPR/Cas9 as a treatment option for AD by targeting specific genes including those that cause early-onset AD, as well as those that are significant risk factors for late-onset AD such as the apolipoprotein E4 (APOE4) gene.
Objective To determine whether occipital and cingulate hypometabolism is being under-reported or missed on 18-fluorodeoxyglucose positron emission tomography (FDG-PET) CT scans in patients with Dementia with Lewy Bodies (DLB). Background Recent studies have reported higher sensitivity and specificity for occipital and cingulate hypometabolism on FDG-PET of DLB patients. Methods This retrospective chart review looked at regions of interest (ROI’s) in FDG-PET CT scan reports in 35 consecutive patients with a clinical diagnosis of probable, possible, or definite DLB as defined by the latest DLB Consortium Report. ROI’s consisting of glucose hypometabolism in frontal, parietal, temporal, occipital, and cingulate areas were tabulated and charted separately by the authors from the reports. A blinded Nuclear medicine physician read the images independently and marked ROI’s separately. A Cohen’s Kappa coefficient statistic was calculated to determine agreement between the reports and the blinded reads. Results On the radiology reports, 25.71% and 17.14% of patients reported occipital and cingulate hypometabolism respectively. Independent reads demonstrated significant disagreement with the proportion of occipital and cingulate hypometabolism being reported on initial reads: 91.43% and 85.71% respectively. Cohen’s Kappa statistic determinations demonstrated significant agreement only with parietal hypometabolism (p<0.05). Conclusion Occipital and cingulate hypometabolism is under-reported and missed frequently on clinical interpretations of FDG-PET scans of patients with DLB, but the frequency of hypometabolism is even higher than previously reported. Further studies with more statistical power and receiver operating characteristic analyses are needed to delineate the sensitivity and specificity of these in vivo biomarkers.
Aluminum is a ubiquitous neurotoxin highly enriched in our biosphere, and has been implicated in the etiology and pathology of multiple neurological diseases that involve inflammatory neural degeneration, behavioral impairment and cognitive decline. Over the last 36 years our group has analyzed the aluminum content of the temporal lobe neocortex of 511 high quality coded human brain samples from 18 diverse neurological and neurodegenerative disorders, including 2 groups of age-matched controls. Brodmann anatomical areas including the inferior, medial and superior temporal gyrus (A20-A22) were selected for analysis: (i) because of their essential functions in massive neural information processing operations including cognition and memory formation; and (ii) because subareas of these anatomical regions are unique to humans and are amongst the earliest areas affected by progressive neurodegenerative disorders such as Alzheimer's disease (AD). Coded brain tissue samples were analyzed using the analytical technique of: (i) Zeeman-type electrothermal atomic absorption spectrophotometry (ETAAS) combined with (ii) an experimental multi-elemental analysis using the advanced photon source (APS) ultra-bright storage ring-generated hard X-ray beam (7 GeV) and fluorescence raster scanning (XRFR) spectroscopy device at the Argonne National Laboratory, US Department of Energy, University of Chicago IL, USA. These data represent the largest study of aluminum concentration in the brains of human neurological and neurodegenerative disease ever undertaken. Neurological diseases examined were AD (N=186), ataxia Friedreich's type (AFT; N=6), amyotrophic lateral sclerosis (ALS; N=16), autism spectrum disorder (ASD; N=26), dialysis dementia syndrome (DDS; N=27), Down's syndrome (DS; trisomy21; N=24), Huntington's chorea (HC; N=15), multiple infarct dementia (MID; N=19), multiple sclerosis (MS; N=23), Parkinson's disease (PD; N=27), prion disease (PrD; N=11) including bovine spongiform encephalopathy (BSE; 'mad cow disease'), Creutzfeldt-Jakob disease (CJD) and Gerstmann-Straussler-Sheinker syndrome (GSS), progressive multifocal leukoencephalopathy (PML; N=11), progressive supranuclear palsy (PSP; N=24), schizophrenia (SCZ; N=21), a young control group (YCG; N=22) and an aged control group (ACG; N=53). Amongst these 18 common neurological conditions and controls we report a statistically significant trend for aluminum to be increased only in AD, DS and DDS compared to age- and gender-matched brains from the same anatomical region. The results continue to suggest that aluminum's association with AD, DDS and DS brain tissues may contribute to the neuropathology of these neurological diseases but appear not to be a significant factor in other common disorders of the human central nervous system (CNS).
The first examples of reversal of cognitive decline in Alzheimer’s disease and the pre-Alzheimer’s disease conditions MCI (Mild Cognitive Impairment) and SCI (Subjective Cognitive Impairment) have recently been published. These two publications described a total of 19 patients showing sustained subjective and objective improvement in cognition, using a comprehensive, precision medicine approach that involves determining the potential contributors to the cognitive decline (e.g., activation of the innate immune system by pathogens or intestinal permeability, reduction in trophic or hormonal support, specific toxin exposure, or other contributors), using a computer-based algorithm to determine subtype and then addressing each contributor using a personalized, targeted, multi-factorial approach dubbed ReCODE for reversal of cognitive decline. An obvious criticism of the initial studies is the small number of patients reported. Therefore, we report here 100 patients, treated by several different physicians, with documented improvement in cognition, in some cases with documentation of improvement in electrophysiology or imaging, as well. This additional report provides further support for a randomized, controlled clinical trial of the protocol and the overall approach. Citation: Bredesen DE, Sharlin K, Jenkins D, Okuno M, Youngberg W, et al. (2018) Reversal of Cognitive Decline: 100 Patients. J Alzheimers Dis Parkinsonism 8: 450. doi: 10.4172/2161-0460.1000450
Objective: In this pilot study hypothesizing that blood-CSF barrier (BCSFB) function is altered in mild cognitive impairment (MCI), we evaluated small-sized biomarker distribution between serum (SER) and cerebrospinal fluid (CSF). For both MCI and Alzheimer (AD) patients we quantified CSF neurochemistry; and compared CSF/SER ratios for urea and creatinine, as well as albumin, to those of healthy controls. Methods: A compromised BCSFB in neurodegenerative states alters CSF-to-serum (CSF/SER) concentrations. We analyzed urea, creatinine and albumin, for transbarrier (across choroid plexus) distribution between CSF and serum, from patients with MCI (n=8) or AD (n=13). Lumbar CSF and arterial blood were frozen/analyzed by multiplex technology. Results: In healthy controls, the CSF creatinine was significantly concentrated ~50% above the serum level. In both MCI and AD, the CSF creatinine concentration decreased while the urea level increased; CSF albumin was also elevated in AD. CSF/SER ratios for controls, MCI and AD were: urea 0.80, 0.98, 0.86; creatinine 1.52, 1.13, 1.14; and albumin 0.0045, 0.0051, 0.0065. Thus, CSF/SER ratios for creatinine and urea in MCI were similar to those in AD patients. Conclusion: Blood-CSF barrier compromise in MCI resembled that in AD. In cognitively-impaired patients, the dissipating ratios toward equilibrium suggest disease-altered BCSFB permeability (urea and albumin) and transporter activity (creatinine/creatine). We propose that redistribution of urea and creatinine, between serum and CSF, are useful biomarkers for evaluating disease-induced alterations in CSF biochemistry and BCSFB functional status.
