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Xu L, Ren C, Jing C, Wang G, Wei H, Kong M, Ba M. Predicting amyloid-PET and clinical conversion in apolipoprotein E ε3/ε3 non-demented individuals with multidimensional factors. Eur J Neurosci 2024; 60:3742-3758. [PMID: 38698692 DOI: 10.1111/ejn.16376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/14/2024] [Accepted: 04/16/2024] [Indexed: 05/05/2024]
Abstract
The apolipoprotein E (APOE) ε4 is a well-established risk factor of amyloid-β (Aβ) in Alzheimer's disease (AD). However, because of the high prevalence of APOE ε3, there may be a large number of people with APOE ε3/ε3 who are non-demented and have Aβ pathology. There are limited studies on assessing Aβ status and clinical conversion in the APOE ε3/ε3 non-demented population. Two hundred and ninety-three non-demented individuals with APOE ε3/ε3 from ADNI database were divided into Aβ-positron emission tomography (Aβ-PET) positivity (+) and Aβ-PET negativity (-) groups using cut-off value of >1.11. Stepwise regression searched for a single or multidimensional clinical variables for predicting Aβ-PET (+), and the receiver operating characteristic curve (ROC) assessed the accuracy of the predictive models. The Cox regression model explored the risk factors associated with clinical conversion to mild cognitive impairment (MCI) or AD. The results showed that the combination of sex, education, ventricle and white matter hyperintensity (WMH) volume can accurately predict Aβ-PET status in cognitively normal (CN), and the combination of everyday cognition study partner total (EcogSPTotal) score, age, plasma p-tau 181 and WMH can accurately predict Aβ-PET status in MCI individuals. EcogSPTotal score were independent predictors of clinical conversion to MCI or AD. The findings may provide a non-invasive and effective tool to improve the efficiency of screening Aβ-PET (+), accelerate and reduce costs of AD trial recruitment in future secondary prevention trials or help to select patients at high risk of disease progression in clinical trials.
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Affiliation(s)
- Lijuan Xu
- Department of Neurology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Shandong, China
| | - Chao Ren
- Department of Neurology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Shandong, China
| | - Chenxi Jing
- Department of Neurology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Shandong, China
| | - Gang Wang
- School of Ulsan Ship and Ocean College, Ludong University, Yantai, China
| | - Hongchun Wei
- Department of Neurology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Shandong, China
| | - Min Kong
- Department of Neurology, Yantaishan Hospital, Yantai City, Shandong, China
| | - Maowen Ba
- Department of Neurology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Shandong, China
- Yantai Regional Sub Center of National Center for Clinical Medical Research of Neurological Diseases, Shandong, China
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2
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Barthélemy NR, Li Y, Joseph-Mathurin N, Gordon BA, Hassenstab J, Benzinger TLS, Buckles V, Fagan AM, Perrin RJ, Goate AM, Morris JC, Karch CM, Xiong C, Allegri R, Mendez PC, Berman SB, Ikeuchi T, Mori H, Shimada H, Shoji M, Suzuki K, Noble J, Farlow M, Chhatwal J, Graff-Radford NR, Salloway S, Schofield PR, Masters CL, Martins RN, O'Connor A, Fox NC, Levin J, Jucker M, Gabelle A, Lehmann S, Sato C, Bateman RJ, McDade E. A soluble phosphorylated tau signature links tau, amyloid and the evolution of stages of dominantly inherited Alzheimer's disease. Nat Med 2020; 26:398-407. [PMID: 32161412 PMCID: PMC7309367 DOI: 10.1038/s41591-020-0781-z] [Citation(s) in RCA: 337] [Impact Index Per Article: 84.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 01/30/2020] [Indexed: 12/31/2022]
Abstract
Development of tau-based therapies for Alzheimer's disease requires an understanding of the timing of disease-related changes in tau. We quantified the phosphorylation state at multiple sites of the tau protein in cerebrospinal fluid markers across four decades of disease progression in dominantly inherited Alzheimer's disease. We identified a pattern of tau staging where site-specific phosphorylation changes occur at different periods of disease progression and follow distinct trajectories over time. These tau phosphorylation state changes are uniquely associated with structural, metabolic, neurodegenerative and clinical markers of disease, and some (p-tau217 and p-tau181) begin with the initial increases in aggregate amyloid-β as early as two decades before the development of aggregated tau pathology. Others (p-tau205 and t-tau) increase with atrophy and hypometabolism closer to symptom onset. These findings provide insights into the pathways linking tau, amyloid-β and neurodegeneration, and may facilitate clinical trials of tau-based treatments.
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Affiliation(s)
- Nicolas R Barthélemy
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Yan Li
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA.,Division of Biostatistics, Washington University School of Medicine, Saint Louis, MO, USA
| | - Nelly Joseph-Mathurin
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Brian A Gordon
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Jason Hassenstab
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Tammie L S Benzinger
- Department of Radiology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Virginia Buckles
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Anne M Fagan
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Richard J Perrin
- Department of Pathology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Alison M Goate
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - John C Morris
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Celeste M Karch
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, USA
| | - Chengjie Xiong
- Division of Biostatistics, Washington University School of Medicine, Saint Louis, MO, USA
| | - Ricardo Allegri
- Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia (FLENI) Instituto de Investigaciones Neurológicas Raúl Correa, Buenos Aires, Argentina
| | - Patricio Chrem Mendez
- Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia (FLENI) Instituto de Investigaciones Neurológicas Raúl Correa, Buenos Aires, Argentina
| | - Sarah B Berman
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | | | | | | | | | - James Noble
- Columbia University, College of Physicians and Surgeons, New York, NY, USA
| | - Martin Farlow
- Department of Neurology, Indiana University, Indianapolis, IN, USA
| | - Jasmeer Chhatwal
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Stephen Salloway
- Butler Hospital, Providence, RI, USA.,Brown University, Providence, RI, USA
| | - Peter R Schofield
- Neuroscience Research Australia, Sydney, New South Wales, Australia.,School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Colin L Masters
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia.,University of Melbourne, Melbourne, Victoria, Australia
| | | | - Antoinette O'Connor
- Dementia Research Centre, Institute of Neurology, University College London, London, UK
| | - Nick C Fox
- Dementia Research Centre, Institute of Neurology, University College London, London, UK
| | - Johannes Levin
- German Center for Neurodegenerative Diseases (DZNE) Munich, Munich, Germany.,Department of Neurology, Ludwig-Maximilians Universität München, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Mathias Jucker
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany.,Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Audrey Gabelle
- Laboratoire de Biochimie et Protéomique Clinique and CRB, INSERM-UM, CHU Montpellier, Montpellier, France, Montpellier, France
| | - Sylvain Lehmann
- Laboratoire de Biochimie et Protéomique Clinique and CRB, INSERM-UM, CHU Montpellier, Montpellier, France, Montpellier, France
| | - Chihiro Sato
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Randall J Bateman
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA.
| | - Eric McDade
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO, USA.
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Kreisl WC, Jin P, Lee S, Dayan ER, Vallabhajosula S, Pelton G, Luchsinger JA, Pradhaban G, Devanand DP. Odor Identification Ability Predicts PET Amyloid Status and Memory Decline in Older Adults. J Alzheimers Dis 2019; 62:1759-1766. [PMID: 29614678 DOI: 10.3233/jad-170960] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Odor identification deficits occur in Alzheimer's disease (AD), as measured by the 40-item University of Pennsylvania Smell Identification Test (UPSIT). OBJECTIVE To determine if UPSIT scores predict amyloid-β (Aβ) status, determined by 11C-Pittsburgh Compound B PET. We also compared UPSIT scores to Aβ status in predicting future memory decline. METHODS Subjects were recruited into a longitudinal clinical prediction study. We analyzed data from those who had UPSIT, cognitive testing, PIB PET, and at least 12 months' clinical follow-up. Forty-six amnestic mild cognitive impairment patients and 25 cognitively normal controls were included. Amyloid-positivity was defined as composite PIB standardized uptake value ratio >1.5. Logistic regression and Receiver Operating Characteristic Curve analyses tested the predictive utility of impaired olfaction (defined as UPSIT score <35) and amyloid-positivity for memory decline. RESULTS High UPSIT scores predicted absence of amyloidosis on PET, with negative predictive value of 100%. Positive predictive value of low UPSIT scores on positive Aβ status was only 41%. Both low UPSIT score (OR = 4.301, 95% CI = 1.248, 14.821, p = 0.021) and positive PET scan (OR = 20.898, 95% CI = 2.222, 196.581, p = 0.008) predicted memory decline. CONCLUSION Individuals with high UPSIT scores are less likely to have cerebral amyloidosis or experience memory decline. Therefore, UPSIT has potential as a screening tool to determine utility of Aβ PET in clinical practice or enrollment in clinical trials. Low UPSIT score is a non-specific marker of neurodegeneration that could indicate further workup in patients with memory complaints.
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Affiliation(s)
| | - Peng Jin
- Division of Biostatistics, Columbia University Medical Center, New York, NY, USA
| | - Seonjoo Lee
- Division of Biostatistics, Columbia University Medical Center, New York, NY, USA
| | - Ezra R Dayan
- Taub Institute, Columbia University Medical, New York, NY, USA
| | | | - Gregory Pelton
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA
| | - José A Luchsinger
- Departments of Medicine and Epidemiology, Columbia University Medical Center, New York, NY, USA
| | | | - D P Devanand
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA
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Pouclet-Courtemanche H, Nguyen TB, Skrobala E, Boutoleau-Bretonnière C, Pasquier F, Bouaziz-Amar E, Bigot-Corbel E, Schraen S, Dumurgier J, Paquet C, Lebouvier T. Frontotemporal dementia is the leading cause of "true" A-/T+ profiles defined with Aβ 42/40 ratio. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2019; 11:161-169. [PMID: 30815533 PMCID: PMC6378630 DOI: 10.1016/j.dadm.2019.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Introduction Patients with positive tauopathy but negative Aβ42 (A−T+) in the cerebrospinal fluid (CSF) represent a diagnostic challenge. The Aβ42/40 ratio supersedes Aβ42 and reintegrates “false” A−T+ patients into the Alzheimer's disease spectrum. However, the biomarker and clinical characteristics of “true” and “false” A−T+ patients remain elusive. Methods Among the 509 T+N+ patients extracted from the databases of three memory clinics, we analyzed T+N+ patients with normal Aβ42 and compared “false” A−T+ with abnormal Aβ42/40 ratio and “true” A−T+ patients with normal Aβ42/40 ratio, before CSF analysis and at follow-up. Results 24.9% of T+N+ patients had normal Aβ42 levels. Among them, 42.7% were “true” A−T+. “True” A−T+ had lower CSF tauP181 than “false” A−T+ patients. 48.0% of “true” A−T+ patients were diagnosed with frontotemporal lobar degeneration before CSF analysis and 64.0% at follow-up, as compared with 6% in the “false” A−T+ group (P < .0001). Discussion Frontotemporal lobar degeneration is probably the main cause of “true” A−T+ profiles. Dementia with normal cerebrospinal fluid Aβ42 yet high cerebrospinal fluid tau181P is a situation referred to as A−T+N+ in the 2018 National Institute of Aging–Alzheimer's Association research framework. The interpretation of A−T+N+ profiles is not consensual and uncomfortable for clinicians. The use of Aβ42/40 ratio as a surrogate amyloid marker halves the number of uninformative A−T+N+ profiles. T+N+ patients with normal Aβ42 yet abnormal Aβ42/40 have an Alzheimer's phenotype. Frontotemporal lobar degeneration is probably the leading cause of A−T+N+ profiles.
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Affiliation(s)
- Hélène Pouclet-Courtemanche
- CHU Nantes, Inserm CIC04, Department of Neurology, Centre Mémoire de Ressources et Recherche, Nantes, France
| | | | | | | | - Florence Pasquier
- University of Lille, Inserm U1171, CHU Lille, DISTALZ, Lille, France
| | - Elodie Bouaziz-Amar
- Département de Biochimie et de biologie moléculaire GH Saint-Louis/Lariboisière/Fernand Widal - Site Lariboisière, AP-HP, Paris, France.,Inserm UMR-S 1144 Universités Paris Descartes - Paris Diderot Variabilité de Réponse aux Psychotropes, Paris, France
| | | | - Susanna Schraen
- University of Lille, Inserm U1172, CHU Lille, DISTALZ, Lille, France
| | - Julien Dumurgier
- Cognitive Neurology Center, Lariboisiere - Fernand Widal Hospital, AP-HP, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Claire Paquet
- Cognitive Neurology Center, Lariboisiere - Fernand Widal Hospital, AP-HP, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Thibaud Lebouvier
- University of Lille, Inserm U1172, CHU Lille, DISTALZ, Lille, France
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5
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Ba M, Ng KP, Gao X, Kong M, Guan L, Yu L. The combination of apolipoprotein E4, age and Alzheimer's Disease Assessment Scale - Cognitive Subscale improves the prediction of amyloid positron emission tomography status in clinically diagnosed mild cognitive impairment. Eur J Neurol 2019; 26:733-e53. [PMID: 30561868 DOI: 10.1111/ene.13881] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 12/06/2018] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE Randomized clinical trials involving anti-amyloid interventions focus on the early stages of Alzheimer's disease (AD) with proven amyloid pathology, using amyloid positron emission tomography (amyloid-PET) imaging or cerebrospinal fluid analysis. However, these investigations are either expensive or invasive and are not readily available in resource-limited centres. Hence, the identification of cost-effective clinical alternatives to amyloid-PET is highly desirable. This study aimed to investigate the accuracy of combined clinical markers in predicting amyloid-PET status in mild cognitive impairment (MCI) individuals. METHODS In all, 406 MCI participants from the Alzheimer's Disease Neuroimaging Initiative database were dichotomized into amyloid-PET(+) and amyloid-PET(-) using a cut-off of >1.11. The accuracies of single clinical markers [apolipoprotein E4 (ApoE4) genotype, demographics, cognitive measures and cerebrospinal fluid analysis] in predicting amyloid-PET status were evaluated using receiver operating characteristic curve analysis. A logistic regression model was then used to determine the optimal model with combined clinical markers to predict amyloid-PET status. RESULTS Cerebrospinal fluid amyloid-β (Aβ) showed the best predictive accuracy of amyloid-PET status [area under the curve (AUC) = 0.927]. Whilst ApoE4 genotype (AUC = 0.737) and Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog) 13 (AUC = 0.724) independently discriminated amyloid-PET(+) and amyloid-PET(-) MCI individuals, the combination of clinical markers (ApoE4 carrier, age >60 years and ADAS-Cog 13 > 13.5) improved the predictive accuracy of amyloid-PET status (AUC = 0.827, P < 0.001). CONCLUSIONS Cerebrospinal fluid Aβ, which is an invasive procedure, is most accurate in predicting amyloid-PET status in MCI individuals. The combination of ApoE4, age and ADAS-Cog 13 also accurately predicts amyloid-PET status. As this combination of clinical markers is cheap, non-invasive and readily available, it offers an attractive surrogate assessment for amyloid status amongst MCI individuals in resource-limited settings.
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Affiliation(s)
- M Ba
- Department of Neurology, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - K P Ng
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
| | - X Gao
- Department of Neurology, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - M Kong
- Department of Neurology, Yantaishan Hospital, Yantai City, China
| | - L Guan
- Department of Neurology, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - L Yu
- Department of Neurology, Yantaishan Hospital, Yantai City, China
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Ritchie C, Smailagic N, Noel‐Storr AH, Ukoumunne O, Ladds EC, Martin S. CSF tau and the CSF tau/ABeta ratio for the diagnosis of Alzheimer's disease dementia and other dementias in people with mild cognitive impairment (MCI). Cochrane Database Syst Rev 2017; 3:CD010803. [PMID: 28328043 PMCID: PMC6464349 DOI: 10.1002/14651858.cd010803.pub2] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Research suggests that measurable change in cerebrospinal fluid (CSF) biomarkers occurs years in advance of the onset of clinical symptoms (Beckett 2010). In this review, we aimed to assess the ability of CSF tau biomarkers (t-tau and p-tau) and the CSF tau (t-tau or p-tau)/ABeta ratio to enable the detection of Alzheimer's disease pathology in patients with mild cognitive impairment (MCI). These biomarkers have been proposed as important in new criteria for Alzheimer's disease dementia that incorporate biomarker abnormalities. OBJECTIVES To determine the diagnostic accuracy of 1) CSF t-tau, 2) CSF p-tau, 3) the CSF t-tau/ABeta ratio and 4) the CSF p-tau/ABeta ratio index tests for detecting people with MCI at baseline who would clinically convert to Alzheimer's disease dementia or other forms of dementia at follow-up. SEARCH METHODS The most recent search for this review was performed in January 2013. We searched MEDLINE (OvidSP), Embase (OvidSP), BIOSIS Previews (Thomson Reuters Web of Science), Web of Science Core Collection, including Conference Proceedings Citation Index (Thomson Reuters Web of Science), PsycINFO (OvidSP), and LILACS (BIREME). We searched specialized sources of diagnostic test accuracy studies and reviews. We checked reference lists of relevant studies and reviews for additional studies. We contacted researchers for possible relevant but unpublished data. We did not apply any language or data restriction to the electronic searches. We did not use any methodological filters as a method to restrict the search overall. SELECTION CRITERIA We selected those studies that had prospectively well-defined cohorts with any accepted definition of MCI and with CSF t-tau or p-tau and CSF tau (t-tau or p-tau)/ABeta ratio values, documented at or around the time the MCI diagnosis was made. We also included studies which looked at data from those cohorts retrospectively, and which contained sufficient data to construct two by two tables expressing those biomarker results by disease status. Moreover, studies were only selected if they applied a reference standard for Alzheimer's disease dementia diagnosis, for example, the NINCDS-ADRDA or Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. DATA COLLECTION AND ANALYSIS We screened all titles generated by the electronic database searches. Two review authors independently assessed the abstracts of all potentially relevant studies, and the full papers for eligibility. Two independent assessors performed data extraction and quality assessment. Where data allowed, we derived estimates of sensitivity at fixed values of specificity from the model we fitted to produce the summary receiver operating characteristic (ROC) curve. MAIN RESULTS In total, 1282 participants with MCI at baseline were identified in the 15 included studies of which 1172 had analysable data; 430 participants converted to Alzheimer's disease dementia and 130 participants to other forms of dementia. Follow-up ranged from less than one year to over four years for some participants, but in the majority of studies was in the range one to three years. Conversion to Alzheimer's disease dementia The accuracy of the CSF t-tau was evaluated in seven studies (291 cases and 418 non-cases).The sensitivity values ranged from 51% to 90% while the specificity values ranged from 48% to 88%. At the median specificity of 72%, the estimated sensitivity was 75% (95% CI 67 to 85), the positive likelihood ratio was 2.72 (95% CI 2.43 to 3.04), and the negative likelihood ratio was 0.32 (95% CI 0.22 to 0.47).Six studies (164 cases and 328 non-cases) evaluated the accuracy of the CSF p-tau. The sensitivities were between 40% and 100% while the specificities were between 22% and 86%. At the median specificity of 47.5%, the estimated sensitivity was 81% (95% CI: 64 to 91), the positive likelihood ratio was 1.55 (CI 1.31 to 1.84), and the negative likelihood ratio was 0.39 (CI: 0.19 to 0.82).Five studies (140 cases and 293 non-cases) evaluated the accuracy of the CSF p-tau/ABeta ratio. The sensitivities were between 80% and 96% while the specificities were between 33% and 95%. We did not conduct a meta-analysis because the studies were few and small. Only one study reported the accuracy of CSF t-tau/ABeta ratio.Our findings are based on studies with poor reporting. A significant number of studies had unclear risk of bias for the reference standard, participant selection and flow and timing domains. According to the assessment of index test domain, eight of 15 studies were of poor methodological quality.The accuracy of these CSF biomarkers for 'other dementias' had not been investigated in the included primary studies. Investigation of heterogeneity The main sources of heterogeneity were thought likely to be reference standards used for the target disorders, sources of recruitment, participant sampling, index test methodology and aspects of study quality (particularly, inadequate blinding).We were not able to formally assess the effect of each potential source of heterogeneity as planned, due to the small number of studies available to be included. AUTHORS' CONCLUSIONS The insufficiency and heterogeneity of research to date primarily leads to a state of uncertainty regarding the value of CSF testing of t-tau, p-tau or p-tau/ABeta ratio for the diagnosis of Alzheimer's disease in current clinical practice. Particular attention should be paid to the risk of misdiagnosis and overdiagnosis of dementia (and therefore over-treatment) in clinical practice. These tests, like other biomarker tests which have been subject to Cochrane DTA reviews, appear to have better sensitivity than specificity and therefore might have greater utility in ruling out Alzheimer's disease as the aetiology to the individual's evident cognitive impairment, as opposed to ruling it in. The heterogeneity observed in the few studies awaiting classification suggests our initial summary will remain valid. However, these tests may have limited clinical value until uncertainties have been addressed. Future studies with more uniformed approaches to thresholds, analysis and study conduct may provide a more homogenous estimate than the one that has been available from the included studies we have identified.
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Affiliation(s)
- Craig Ritchie
- University of EdinburghCentre for Clinical Brain SciencesEdinburghUK
| | - Nadja Smailagic
- University of CambridgeInstitute of Public HealthForvie SiteRobinson WayCambridgeUKCB2 0SR
| | - Anna H Noel‐Storr
- University of OxfordRadcliffe Department of MedicineRoom 4401c (4th Floor)John Radcliffe Hospital, HeadingtonOxfordUKOX3 9DU
| | - Obioha Ukoumunne
- University of Exeter Medical School, University of ExeterNIHR CLAHRC South West Peninsula (PenCLAHRC)Veysey BuildingSalmon Pool LaneExeterDevonUKEX2 4SG
| | - Emma C Ladds
- North Bristol NHS TrustSouthmead hospitalBristolUK
| | - Steven Martin
- University of CambridgeInstitute of Public HealthForvie SiteRobinson WayCambridgeUKCB2 0SR
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7
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Toepper M. Dissociating Normal Aging from Alzheimer's Disease: A View from Cognitive Neuroscience. J Alzheimers Dis 2017; 57:331-352. [PMID: 28269778 PMCID: PMC5366251 DOI: 10.3233/jad-161099] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2017] [Indexed: 02/07/2023]
Abstract
Both normal aging and Alzheimer's disease (AD) are associated with changes in cognition, grey and white matter volume, white matter integrity, neural activation, functional connectivity, and neurotransmission. Obviously, all of these changes are more pronounced in AD and proceed faster providing the basis for an AD diagnosis. Since these differences are quantitative, however, it was hypothesized that AD might simply reflect an accelerated aging process. The present article highlights the different neurocognitive changes associated with normal aging and AD and shows that, next to quantitative differences, there are multiple qualitative differences as well. These differences comprise different neurocognitive dissociations as different cognitive deficit profiles, different weights of grey and white matter atrophy, and different gradients of structural decline. These qualitative differences clearly indicate that AD cannot be simply described as accelerated aging process but on the contrary represents a solid entity.
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Affiliation(s)
- Max Toepper
- Department of Psychiatry and Psychotherapy Bethel, Research Division, Evangelisches Krankenhaus Bielefeld (EvKB), Bielefeld, Germany
- Department of Psychiatry and Psychotherapy Bethel, Department of Geriatric Psychiatry, Evangelisches Krankenhaus Bielefeld (EvKB), Bielefeld, Germany
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8
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McGeer PL, Rogers J, McGeer EG. Inflammation, Antiinflammatory Agents, and Alzheimer’s Disease: The Last 22 Years. J Alzheimers Dis 2016; 54:853-857. [DOI: 10.3233/jad-160488] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Patrick L. McGeer
- Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver BC, Canada
| | - Joseph Rogers
- Biosciences Division SRI International, Menlo Park, CA, USA
| | - Edith G. McGeer
- Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver BC, Canada
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9
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Cognitive variability-A marker for incident MCI and AD: An analysis for the Alzheimer's Disease Neuroimaging Initiative. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2016; 4:47-55. [PMID: 27489880 PMCID: PMC4961828 DOI: 10.1016/j.dadm.2016.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Introduction The potential of intra-individual cognitive variability (IICV) to predict incident mild cognitive impairment (MCI) or Alzheimer's disease (AD) was examined and compared to well-established neuroimaging and genetic predictors. Methods IICV was estimated using four neuropsychological measures for n = 1324 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants who were cognitively healthy or diagnosed with MCI at baseline. IICV was used to predict time to incident MCI or AD, and compared to hippocampal volume loss and APOE ε4 status via survival analysis. Results In survival analyses, controlling for age, education, baseline diagonosis, and APOE ε4 status, likelihood ratio tests indicate that IICV is associated with time to cognitive status change in the full sample (P < .0001), and when the sample was restricted to individuals with MCI at baseline (P < .0001). Discussion These findings suggest IICV may be a low-cost, noninvasive alternative to traditional AD biomarkers.
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10
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Guhra M, Thomas C, Boedeker S, Kreisel S, Driessen M, Beblo T, Ohrmann P, Toepper M. Linking CSF and cognition in Alzheimer's disease: Reanalysis of clinical data. Exp Gerontol 2015; 73:107-13. [PMID: 26585048 DOI: 10.1016/j.exger.2015.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 01/27/2023]
Abstract
OBJECTIVES Memory and executive deficits are important cognitive markers of Alzheimer's disease (AD). Moreover, in the past decade, cerebrospinal fluid (CSF) biomarkers have been increasingly utilized in clinical practice. Both cognitive and CSF markers can be used to differentiate between AD patients and healthy seniors with high diagnostic accuracy. However, the extent to which performance on specific mnemonic or executive tasks enables reliable estimations of the concentrations of different CSF markers and their ratios remains unclear. METHODS To address the above issues, we examined the association between neuropsychological data and CSF biomarkers in 51 AD patients using hierarchical multiple regression analyses. In the first step of these analyses, age, education and sex were entered as predictors to control for possible confounding effects. In the second step, data from a neuropsychological test battery assessing episodic memory, semantic memory and executive functioning were included to determine whether these variables significantly increased (compared to step 1) the explained variance in Aβ42 concentration, p-tau concentration, t-tau concentration, Aβ42/t-tau ratio, and Aβ42/Aβ40 ratio. RESULTS The different models explained 52% of the variance in Aβ42/t-tau ratio, 27% of the variance in Aβ42 concentration, and 28% of the variance in t-tau concentration. In particular, Aβ42/t-tau ratio was associated with verbal recognition and code shifting, with Aβ42 being related to verbal recognition and t-tau being related to code shifting. By contrast, the inclusion of neuropsychological data did not allow reliable estimations of Aβ42/Aβ40 ratio or p-tau concentration. CONCLUSION Our results showed that strong associations exist between the cognitive key symptoms of AD and the concentrations and ratios of specific CSF markers. In addition, we revealed a specific combination of neuropsychological tests that may facilitate reliable estimations of CSF concentrations, thereby providing important diagnostic information for non-invasive early AD detection.
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Affiliation(s)
- Michael Guhra
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany.
| | - Christine Thomas
- Clinical Centre Stuttgart, Clinic for Psychiatry and Psychotherapy for the Elderly, Prießnitzweg 24, D-70374 Stuttgart, Germany
| | - Sebastian Boedeker
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Stefan Kreisel
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Martin Driessen
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Thomas Beblo
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
| | - Patricia Ohrmann
- University of Muenster, Department of Psychiatry, Albert-Schweitzer-Campus 1, A9, D-48149 Muenster, Germany
| | - Max Toepper
- Evangelisches Krankenhaus Bielefeld, Department of Psychiatry and Psychotherapy Bethel, Remterweg 69-71, D-33617 Bielefeld, Germany
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Almeida RP, Schultz SA, Austin BP, Boots EA, Dowling NM, Gleason CE, Bendlin BB, Sager M, Hermann BP, Zetterberg H, Carlsson C, Johnson S, Asthana S, Okonkwo OC. Effect of Cognitive Reserve on Age-Related Changes in Cerebrospinal Fluid Biomarkers of Alzheimer Disease. JAMA Neurol 2015; 72:699-706. [PMID: 25893879 PMCID: PMC4639566 DOI: 10.1001/jamaneurol.2015.0098] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
IMPORTANCE Although advancing age is the strongest risk factor for the development of symptomatic Alzheimer disease (AD), recent studies have shown that there are individual differences in susceptibility to age-related alterations in the biomarkers of AD pathophysiology. OBJECTIVE To investigate whether cognitive reserve (CR) modifies the adverse influence of age on key cerebrospinal fluid (CSF) biomarkers of AD. DESIGN, SETTING, AND PARTICIPANTS A cross-sectional cohort of 268 individuals (211 in a cognitively normal group and 57 in a cognitively impaired group) from the Wisconsin Registry for Alzheimer's Prevention and the Wisconsin Alzheimer's Disease Research Center participated in this study. They underwent lumbar puncture for collection of CSF samples, from which Aβ42, total tau (t-tau), and phosphorylated tau (p-tau) were immunoassayed. In addition, we computed t-tau/Aβ42 and p-tau/Aβ42 ratios. Cognitive reserve was indexed by years of education, with 16 or more years taken to confer high reserve. Covariate-adjusted regression analyses were used to test whether the effect of age on CSF biomarkers was modified by CR. The study dates were March 5, 2010, to February 13, 2013. MAIN OUTCOMES AND MEASURES Cerebrospinal fluid levels of Aβ42, t-tau, p-tau, t-tau/Aβ42, and p-tau/Aβ42. RESULTS There were significant age × CR interactions for CSF t-tau (β [SE] = -6.72 [2.84], P = .02), p-tau (β [SE] = -0.71 [0.27], P = .01), t-tau/Aβ42 (β [SE] = -0.02 [0.01], P = .02), and p-tau/Aβ42 (β [SE] = -0.002 [0.001], P = .004). With advancing age, individuals with high CR exhibited attenuated adverse alterations in these CSF biomarkers compared with individuals with low CR. This attenuation of age effects by CR tended to be more pronounced in the cognitively impaired group compared with the cognitively normal group. There was evidence of a dose-response relationship such that the effect of age on the biomarkers was progressively attenuated given additional years of schooling. CONCLUSIONS AND RELEVANCE In a sample composed of a cognitively normal group and a cognitively impaired group, higher CR was associated with a diminution of age-related alterations in CSF biomarkers of AD. This suggests one pathway through which CR might favorably alter lifetime risk for symptomatic AD.
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Affiliation(s)
- Rodrigo P. Almeida
- Fluminense Federal University, Niteroi, Brazil
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Stephanie A. Schultz
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Benjamin P. Austin
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Elizabeth A. Boots
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - N. Maritza Dowling
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Carey E. Gleason
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Barbara B. Bendlin
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Mark Sager
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Bruce P. Hermann
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, the Sahlgrenska Academy at University of Gothenburg, Mölndal, Sweden
- University of London Institute of Neurology, Queen Square, London, United Kingdom
| | - Cindy Carlsson
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Sterling Johnson
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Sanjay Asthana
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Ozioma C. Okonkwo
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial VA Hospital, Madison WI
- Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI
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Kang JH, Ryoo NY, Shin DW, Trojanowski JQ, Shaw LM. Role of cerebrospinal fluid biomarkers in clinical trials for Alzheimer's disease modifying therapies. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 18:447-56. [PMID: 25598657 PMCID: PMC4296032 DOI: 10.4196/kjpp.2014.18.6.447] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/02/2014] [Accepted: 10/07/2014] [Indexed: 12/27/2022]
Abstract
Until now, a disease-modifying therapy (DMT) that has an ability to slow or arrest Alzheimer's disease (AD) progression has not been developed, and all clinical trials involving AD patients enrolled by clinical assessment alone also have not been successful. Given the growing consensus that the DMT is likely to require treatment initiation well before full-blown dementia emerges, the early detection of AD will provide opportunities to successfully identify new drugs that slow the course of AD pathology. Recent advances in early detection of AD and prediction of progression of the disease using various biomarkers, including cerebrospinal fluid (CSF) Aβ1-42, total tau and p-tau181 levels, and imagining biomarkers, are now being actively integrated into the designs of AD clinical trials. In terms of therapeutic mechanisms, monitoring these markers may be helpful for go/no-go decision making as well as surrogate markers for disease severity or progression. Furthermore, CSF biomarkers can be used as a tool to enrich patients for clinical trials with prospect of increasing statistical power and reducing costs in drug development. However, the standardization of technical aspects of analysis of these biomarkers is an essential prerequisite to the clinical uses. To accomplish this, global efforts are underway to standardize CSF biomarker measurements and a quality control program supported by the Alzheimer's Association. The current review summarizes therapeutic targets of developing drugs in AD pathophysiology, and provides the most recent advances in the
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Affiliation(s)
- Ju-Hee Kang
- Department of Pharmacology and Clinical Pharmacology, Inha University School of Medicine, Incheon 400-712, Korea. ; Hypoxia-related Disease Research Center, Inha University School of Medicine, Incheon 400-712, Korea. ; Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Na-Young Ryoo
- Hypoxia-related Disease Research Center, Inha University School of Medicine, Incheon 400-712, Korea. ; Department of Anatomy, Inha University School of Medicine, Incheon 400-712, Korea
| | - Dong Wun Shin
- Department of Emergency Medicine, Inje University Ilsan Paik Hospital, Ilsan 411-706, Korea
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA. ; Institute on Aging and Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Leslie M Shaw
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA. ; Institute on Aging and Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
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13
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Ritchie C, Smailagic N, Noel‐Storr AH, Takwoingi Y, Flicker L, Mason SE, McShane R. Plasma and cerebrospinal fluid amyloid beta for the diagnosis of Alzheimer's disease dementia and other dementias in people with mild cognitive impairment (MCI). Cochrane Database Syst Rev 2014; 2014:CD008782. [PMID: 24913723 PMCID: PMC6465069 DOI: 10.1002/14651858.cd008782.pub4] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND According to the latest revised National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (now known as the Alzheimer's Association) (NINCDS-ADRDA) diagnostic criteria for Alzheimer's disease dementia of the National Institute on Aging and Alzheimer Association, the confidence in diagnosing mild cognitive impairment (MCI) due to Alzheimer's disease dementia is raised with the application of biomarkers based on measures in the cerebrospinal fluid (CSF) or imaging. These tests, added to core clinical criteria, might increase the sensitivity or specificity of a testing strategy. However, the accuracy of biomarkers in the diagnosis of Alzheimer's disease dementia and other dementias has not yet been systematically evaluated. A formal systematic evaluation of sensitivity, specificity, and other properties of plasma and CSF amyloid beta (Aß) biomarkers was performed. OBJECTIVES To determine the accuracy of plasma and CSF Aß levels for detecting those patients with MCI who would convert to Alzheimer's disease dementia or other forms of dementia over time. SEARCH METHODS The most recent search for this review was performed on 3 December 2012. We searched MEDLINE (OvidSP), EMBASE (OvidSP), BIOSIS Previews (ISI Web of Knowledge), Web of Science and Conference Proceedings (ISI Web of Knowledge), PsycINFO (OvidSP), and LILACS (BIREME). We also requested a search of the Cochrane Register of Diagnostic Test Accuracy Studies (managed by the Cochrane Renal Group).No language or date restrictions were applied to the electronic searches and methodological filters were not used so as to maximise sensitivity. SELECTION CRITERIA We selected those studies that had prospectively well defined cohorts with any accepted definition of cognitive decline, but no dementia, with baseline CSF or plasma Aß levels, or both, documented at or around the time the above diagnoses were made. We also included studies which looked at data from those cohorts retrospectively, and which contained sufficient data to construct two by two tables expressing plasma and CSF Aß biomarker results by disease status. Moreover, studies were only selected if they applied a reference standard for Alzheimer's dementia diagnosis, for example the NINCDS-ADRDA or Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria. DATA COLLECTION AND ANALYSIS We screened all titles generated by the electronic database searches. Two review authors independently assessed the abstracts of all potentially relevant studies. We assessed the identified full papers for eligibility and extracted data to create standard two by two tables. Two independent assessors performed quality assessment using the QUADAS-2 tool. Where data allowed, we derived estimates of sensitivity at fixed values of specificity from the model we fitted to produce the summary receiver operating characteristic (ROC) curve. MAIN RESULTS Alzheimer's disease dementia was evaluated in 14 studies using CSF Aß42. Of the 1349 participants included in the meta-analysis, 436 developed Alzheimer's dementia. Individual study estimates of sensitivity were between 36% and 100% while the specificities were between 29% and 91%. Because of the variation in assay thresholds, we did not estimate summary sensitivity and specificity. However, we derived estimates of sensitivity at fixed values of specificity from the model we fitted to produce the summary ROC curve. At the median specificity of 64%, the sensitivity was 81% (95% CI 72 to 87). This equated to a positive likelihood ratio (LR+) of 2.22 (95% CI 2.00 to 2.47) and a negative likelihood ratio (LR-) of 0.31 (95% CI 0.21 to 0.48).The accuracy of CSF Aß42 for all forms of dementia was evaluated in four studies. Of the 464 participants examined, 188 developed a form of dementia (Alzheimer's disease and other forms of dementia).The thresholds used were between 209 mg/ml and 512 ng/ml. The sensitivities were between 56% and 75% while the specificities were between 47% and 76%. At the median specificity of 75%, the sensitivity was estimated to be 63% (95% CI 22 to 91) from the meta-analytic model. This equated to a LR+ of 2.51 (95% CI 1.30 to 4.86) and a LR- of 0.50 (95% CI 0.16 to 1.51).The accuracy of CSF Aß42 for non-Alzheimer's disease dementia was evaluated in three studies. Of the 385 participants examined, 61 developed non-Alzheimer's disease dementia. Since there were very few studies and considerable variation between studies, the results were not meta-analysed. The sensitivities were between 8% and 63% while the specificities were between 35% and 67%.Only one study examined the accuracy of plasma Aß42 and the plasma Aß42/Aß40 ratio for Alzheimer's disease dementia. The sensitivity of 86% (95% CI 81 to 90) was the same for both tests while the specificities were 50% (95% CI 44 to 55) and 70% (95% CI 64 to 75) for plasma Aß42 and the plasma Aß42/Aß40 ratio respectively. Of the 565 participants examined, 245 developed Alzheimer's dementia and 87 non-Alzheimer's disease dementia.There was substantial heterogeneity between studies. The accuracy of Aß42 for the diagnosis of Alzheimer's disease dementia did not differ significantly (P = 0.8) between studies that pre-specified the threshold for determining test positivity (n = 6) and those that only determined the threshold at follow-up (n = 8). One study excluded a sample of MCI non-Alzheimer's disease dementia converters from their analysis. In sensitivity analyses, the exclusion of this study had no impact on our findings. The exclusion of eight studies (950 patients) that were considered at high (n = 3) or unclear (n = 5) risk of bias for the patient selection domain also made no difference to our findings. AUTHORS' CONCLUSIONS The proposed diagnostic criteria for prodromal dementia and MCI due to Alzheimer's disease, although still being debated, would be fulfilled where there is both core clinical and cognitive criteria and a single biomarker abnormality. From our review, the measure of abnormally low CSF Aß levels has very little diagnostic benefit with likelihood ratios suggesting only marginal clinical utility. The quality of reports was also poor, and thresholds and length of follow-up were inconsistent. We conclude that when applied to a population of patients with MCI, CSF Aß levels cannot be recommended as an accurate test for Alzheimer's disease.
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Affiliation(s)
| | - Nadja Smailagic
- University of CambridgeInstitute of Public HealthForvie SiteRobinson WayCambridgeUKCB2 0SR
| | - Anna H Noel‐Storr
- University of OxfordRadcliffe Department of MedicineRoom 4401c (4th Floor)John Radcliffe Hospital, HeadingtonOxfordUKOX3 9DU
| | - Yemisi Takwoingi
- University of BirminghamPublic Health, Epidemiology and BiostatisticsEdgbastonBirminghamUKB15 2TT
| | - Leon Flicker
- University of Western AustraliaWestern Australian Centre for Health & Ageing ‐ WACHACrawleyPerthWestern AustraliaAustralia6014
| | | | - Rupert McShane
- University of OxfordRadcliffe Department of MedicineRoom 4401c (4th Floor)John Radcliffe Hospital, HeadingtonOxfordUKOX3 9DU
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Efavirenz promotes β-secretase expression and increased Aβ1-40,42 via oxidative stress and reduced microglial phagocytosis: implications for HIV associated neurocognitive disorders (HAND). PLoS One 2014; 9:e95500. [PMID: 24759994 PMCID: PMC3997351 DOI: 10.1371/journal.pone.0095500] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/27/2014] [Indexed: 11/19/2022] Open
Abstract
Efavirenz (EFV) is among the most commonly used antiretroviral drugs globally, causes neurological symptoms that interfere with adherence and reduce tolerability, and may have central nervous system (CNS) effects that contribute in part to HIV associated neurocognitive disorders (HAND) in patients on combination antiretroviral therapy (cART). Thus we evaluated a commonly used EFV containing regimen: EFV/zidovudine (AZT)/lamivudine (3TC) in murine N2a cells transfected with the human “Swedish” mutant form of amyloid precursor protein (SweAPP N2a cells) to assess for promotion of amyloid-beta (Aβ) production. Treatment with EFV or the EFV containing regimen generated significantly increased soluble amyloid beta (Aβ), and promoted increased β-secretase-1 (BACE-1) expression while 3TC, AZT, or, vehicle control did not significantly alter these endpoints. Further, EFV or the EFV containing regimen promoted significantly more mitochondrial stress in SweAPP N2a cells as compared to 3TC, AZT, or vehicle control. We next tested the EFV containing regimen in Aβ - producing Tg2576 mice combined or singly using clinically relevant doses. EFV or the EFV containing regimen promoted significantly more BACE-1 expression and soluble Aβ generation while 3TC, AZT, or vehicle control did not. Finally, microglial Aβ phagocytosis was significantly reduced by EFV or the EFV containing regimen but not by AZT, 3TC, or vehicle control alone. These data suggest the majority of Aβ promoting effects of this cART regimen are dependent upon EFV as it promotes both increased production, and decreased clearance of Aβ peptide.
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Nikolcheva T, Jäger S, Bush TA, Vargas G. Challenges in the development of companion diagnostics for neuropsychiatric disorders. Expert Rev Mol Diagn 2014; 11:829-37. [DOI: 10.1586/erm.11.67] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Tania Nikolcheva
- Pharma Research and Early Development CNS Biomarkers Section, F. Hoffmann-La Roche, CH-4070 Basel, Switzerland
| | - Stephan Jäger
- Roche Diagnostics GmbH, DBB-L, Nonnenwald 2, 82377 Penzberg, Germany
| | - Theresa Ambrose Bush
- Roche Diagnostics, 9115 Hague Road, PO Box 50457, Indianapolis, IN 46250-0457, USA
| | - Gabriel Vargas
- Pharma Research and Early Development CNS Biomarkers Section, F. Hoffmann-La Roche, CH-4070 Basel, Switzerland
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Swaminathan S, Risacher SL, Yoder KK, West JD, Shen L, Kim S, Inlow M, Foroud T, Jagust WJ, Koeppe RA, Mathis CA, Shaw LM, Trojanowski JQ, Soares H, Aisen PS, Petersen RC, Weiner MW, Saykin AJ. Association of plasma and cortical amyloid beta is modulated by APOE ε4 status. Alzheimers Dement 2014; 10:e9-e18. [PMID: 23541187 PMCID: PMC3750076 DOI: 10.1016/j.jalz.2013.01.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 01/10/2013] [Accepted: 01/16/2013] [Indexed: 10/27/2022]
Abstract
BACKGROUND Apolipoprotein E (APOE) ε4 allele's role as a modulator of the relationship between soluble plasma amyloid beta (Aβ) and fibrillar brain Aβ measured by Pittsburgh compound B positron emission tomography ([(11)C]PiB PET) has not been assessed. METHODS Ninety-six Alzheimer's Disease Neuroimaging Initiative participants with [(11)C]PiB scans and plasma Aβ1-40 and Aβ1-42 measurements at the time of PET scanning were included. Regional and voxelwise analyses of [(11)C]PiB data were used to determine the influence of APOE ε4 allele on association of plasma Aβ1-40, Aβ1-42, and Aβ1-40/Aβ1-42 with [(11)C]PiB uptake. RESULTS In APOE ε4- but not ε4+ participants, positive relationships between plasma Aβ1-40/Aβ1-42 and [(11)C]PiB uptake were observed. Modeling the interaction of APOE and plasma Aβ1-40/Aβ1-42 improved the explained variance in [(11)C]PiB binding compared with using APOE and plasma Aβ1-40/Aβ1-42 as separate terms. CONCLUSIONS The results suggest that plasma Aβ is a potential Alzheimer's disease biomarker and highlight the importance of genetic variation in interpretation of plasma Aβ levels.
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Affiliation(s)
- Shanker Swaminathan
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Shannon L Risacher
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Karmen K Yoder
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - John D West
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Li Shen
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sungeun Kim
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Mark Inlow
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Mathematics, Rose-Hulman Institute of Technology, Terre Haute, IN, USA
| | - Tatiana Foroud
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William J Jagust
- Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, CA, USA
| | - Robert A Koeppe
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leslie M Shaw
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | | | - Paul S Aisen
- Department of Neurosciences, University of California at San Diego, San Diego, CA, USA
| | - Ronald C Petersen
- Department of Neurology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Michael W Weiner
- Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA
| | - Andrew J Saykin
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA.
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McGeer PL, McGeer EG. The amyloid cascade-inflammatory hypothesis of Alzheimer disease: implications for therapy. Acta Neuropathol 2013; 126:479-97. [PMID: 24052108 DOI: 10.1007/s00401-013-1177-7] [Citation(s) in RCA: 302] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 09/03/2013] [Accepted: 09/05/2013] [Indexed: 12/14/2022]
Abstract
The amyloid cascade hypothesis is widely accepted as the centerpiece of Alzheimer disease (AD) pathogenesis. It proposes that abnormal production of beta amyloid protein (Abeta) is the cause of AD and that the neurotoxicity is due to Abeta itself or its oligomeric forms. We suggest that this, in itself, cannot be the cause of AD because demonstrating such toxicity requires micromolar concentrations of these Abeta forms, while their levels in brain are a million times lower in the picomolar range. AD probably results from the inflammatory response induced by extracellular Abeta deposits, which later become enhanced by aggregates of tau. The inflammatory response, which is driven by activated microglia, increases over time as the disease progresses. Disease-modifying therapeutic attempts to date have failed and may continue to do so as long as the central role of inflammation is not taken into account. Multiple epidemiological and animal model studies show that NSAIDs, the most widely used antiinflammatory agents, have a substantial sparing effect on AD. These studies provide a proof of concept regarding the anti-inflammatory approach to disease modification. Biomarker studies have indicated that early intervention may be necessary. They have established that disease onset occurs more than a decade before it becomes clinically evident. By combining biomarker and pathological data, it is possible to define six phases of disease development, each separated by about 5 years. Phase one can be identified by decreases in Abeta in the CSF, phase 2 by increases of tau in the CSF plus clear evidence of Abeta brain deposits by PET scanning, phase 3 by slight decreases in brain metabolic rate by PET-FDG scanning, phase 4 by slight decreases in brain volume by MRI scanning plus minimal cognitive impairment, phase 5 by increased scanning abnormalities plus clinical diagnosis of AD, and phase 6 by advanced AD requiring institutional care. Utilization of antiinflammatory agents early in the disease process remains an overlooked therapeutic opportunity. Such agents, while not preventative, have the advantage of being able to inhibit the consequences of both Abeta and tau aggregation. Since there is more than a decade between disease onset and cognitive decline, a window of opportunity exists to introduce truly effective disease-modifying regimens. Taking advantage of this opportunity is the challenge for the future.
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Affiliation(s)
- Patrick L McGeer
- Kinsmen Laboratory of Neurological Research, University of British Columbia, 2255 Wesbrook Mall, Vancouver, BC, V6T1Z3, Canada,
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Randall C, Mosconi L, de Leon M, Glodzik L. Cerebrospinal fluid biomarkers of Alzheimer's disease in healthy elderly. FRONT BIOSCI-LANDMRK 2013; 18:1150-73. [PMID: 23747874 PMCID: PMC3904672 DOI: 10.2741/4170] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Numerous studies have shown that Alzheimer's Disease (AD) pathology begins before the onset of clinical symptoms. Because therapies are likely to be more effective if they are implemented early in the disease progression, it is necessary to identify reliable biomarkers to detect AD pathology in the early stages of the disease, ideally in presymptomatic individuals. Recent research has identified three candidate cerebrospinal fluid (CSF) biomarkers that reflect AD pathology: amyloid beta, total tau protein (t-tau), and tau protein phosphorylated at AD-specific epitopes (p-tau). They are useful in supporting the AD diagnosis and have predictive value for AD when patients are in the stage of mild cognitive impairment (MCI). However, their predictive utility in cognitively healthy subjects is still being evaluated. We conducted a review of studies published between 1993 and 2011 and summarized their findings on the role of CSF biomarkers for AD in healthy elderly.
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Affiliation(s)
- Catherine Randall
- Center for Brain Health, 145 East 32nd Street, 5th floor. New York, NY 10016
| | - Lisa Mosconi
- Center for Brain Health, 145 East 32nd Street, 5th floor. New York, NY 10016
| | - Mony de Leon
- Center for Brain Health, 145 East 32nd Street, 5th floor. New York, NY 10016
| | - Lidia Glodzik
- Center for Brain Health, 145 East 32nd Street, 5th floor. New York, NY 10016
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Cardenas VA, Tosun D, Chao LL, Fletcher PT, Joshi S, Weiner MW, Schuff N. Voxel-wise co-analysis of macro- and microstructural brain alteration in mild cognitive impairment and Alzheimer's disease using anatomical and diffusion MRI. J Neuroimaging 2013; 24:435-43. [PMID: 23421601 DOI: 10.1111/jon.12002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 10/01/2012] [Accepted: 10/28/2012] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE To determine if a voxel-wise "co-analysis" of structural and diffusion tensor magnetic resonance imaging (MRI) together reveals additional brain regions affected in mild cognitive impairment (MCI) and Alzheimer's disease (AD) than voxel-wise analysis of the individual MRI modalities alone. METHODS Twenty-one patients with MCI, 21 patients with AD, and 21 cognitively normal healthy elderly were studied with MRI. Maps of deformation and fractional anisotropy (FA) were computed and used as dependent variables in univariate and multivariate statistical models. RESULTS Univariate voxel-wise analysis of macrostructural changes in MCI showed atrophy in the right anterior temporal lobe, left posterior parietal/precuneus region, WM adjacent to the cingulate gyrus, and dorsolateral prefrontal regions, consistent with prior research. Univariate voxel-wise analysis of microstructural changes in MCI showed reduced FA in the left posterior parietal region extending into the corpus callosum, consistent with previous work. The multivariate analysis, which provides more information than univariate tests when structural and FA measures are correlated, revealed additional MCI-related changes in corpus callosum and temporal lobe. CONCLUSION These results suggest that in corpus callosum and temporal regions macro- and microstructural variations in MCI can be congruent, providing potentially new insight into the mechanisms of brain tissue degeneration.
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Affiliation(s)
- Valerie A Cardenas
- University of California, San Francisco, CA; Veterans Affairs Medical Center, San Francisco, CA
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20
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Grill JD, Johnson DK, Burns JM. Should we disclose amyloid imaging results to cognitively normal individuals? Neurodegener Dis Manag 2013; 3:43-51. [PMID: 25285157 PMCID: PMC4184474 DOI: 10.2217/nmt.12.75] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Demonstration of brain accumulation of fibrillar amyloid beta protein via positron emission tomography (PET) with amyloid specific ligands may support the diagnosis of Alzheimer's disease (AD). There is increasing recognition of the potential use of amyloid imaging to detect in vivo the pathology of AD in individuals with no ostensible cognitive impairment. Research use of amyloid PET in cognitively normal patients will be key to pursuit of therapies able to delay cognitive impairment and dementia due to AD. We review the pros and cons of disclosing amyloid imaging results to cognitively normal individuals in clinical and research settings and provide draft recommendations.
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Affiliation(s)
- Joshua D. Grill
- Mary S. Easton Center for Alzheimer's Disease Research, Department of Neurology, UCLA David Geffen School of Medicine
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21
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The diagnosis and evaluation of dementia and mild cognitive impairment with emphasis on SPECT perfusion neuroimaging. CNS Spectr 2012; 17:176-206. [PMID: 22929226 DOI: 10.1017/s1092852912000636] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
As the world population ages, the incidence of dementing illnesses will dramatically increase. The number of people afflicted with dementia is expected to quadruple in the next 50 years. Since the neuropathology of the dementias precedes clinical symptoms often by several years, earlier detection and intervention could be key steps to mitigating the progression and burden of these diseases. This review will explore methods of evaluating, differentiating, and diagnosing the multiple forms of dementia. Particular emphasis will be placed on the diagnosis of mild cognitive impairment-the precursor to dementia. Anatomical imaging; cerebrospinal fluid markers; functional neuroimaging, such as positron emission tomography and single photon emission tomography; and molecular imaging, such as amyloid marker imaging, will be assessed in terms of sensitivity and specificity. Cost will also be a consideration, as the growing population afflicted with dementia represents an increasingly large financial encumbrance to the healthcare systems of every nation. In the face of expensive new markers and limited availability of cyclotrons, single photon emission computer tomography (SPECT) provides relatively high sensitivity and specificity at a comparatively low overall cost.
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Kuller LH, Lopez OL. Dementia and Alzheimer's disease: a new direction.The 2010 Jay L. Foster Memorial Lecture. Alzheimers Dement 2012; 7:540-50. [PMID: 21889117 DOI: 10.1016/j.jalz.2011.05.901] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 05/03/2011] [Indexed: 01/18/2023]
Abstract
BACKGROUND The modern era of Alzheimer's disease (AD) research began in the early 1980s with the establishment of AD research centers and expanded research programs at the National Institute on Aging. METHODS Over the past 30 years, there has been success in defining criteria for AD and dementia, association of important genetic disorders related to premature dementia in families, the association of apolipoprotein-E(4), and measurement of incidence and prevalence and selected risk factors. However, prevention and treatment have been elusive. RESULTS The development of new technologies, especially magnetic resonance imaging, positron emission tomography to measure amyloid in vivo in the brain and glucose metabolism, cerebrospinal fluid examination, better genetic markers, large-scale longitudinal epidemiology studies, and preventive clinical trials has rapidly begun a new era of research that offers opportunities to better understand etiology, that is, determinants of amyloid biology in the brain, neurofibrillary tangles, synaptic loss, and dementia. CONCLUSIONS There are three major hypotheses related to dementia: amyloid deposition and secondary synaptic loss as a unique disease, vascular injury, and "aging." New research must be hypothesis-driven and lead to testable approaches for treatment and prevention.
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Affiliation(s)
- Lewis H Kuller
- Department of Epidemiology, University of Pittsburgh, PA, USA.
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23
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Gross AL, Inouye SK, Rebok GW, Brandt J, Crane PK, Parisi JM, Tommet D, Bandeen-Roche K, Carlson MC, Jones RN. Parallel but not equivalent: challenges and solutions for repeated assessment of cognition over time. J Clin Exp Neuropsychol 2012; 34:758-72. [PMID: 22540849 PMCID: PMC3574868 DOI: 10.1080/13803395.2012.681628] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Analyses of individual differences in change may be unintentionally biased when versions of a neuropsychological test used at different follow-ups are not of equivalent difficulty. This study's objective was to compare mean, linear, and equipercentile equating methods and demonstrate their utility in longitudinal research. STUDY DESIGN AND SETTING The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE, N = 1,401) study is a longitudinal randomized trial of cognitive training. The Alzheimer's Disease Neuroimaging Initiative (ADNI, n = 819) is an observational cohort study. Nonequivalent alternate versions of the Auditory Verbal Learning Test (AVLT) were administered in both studies. RESULTS Using visual displays, raw and mean-equated AVLT scores in both studies showed obvious nonlinear trajectories in reference groups that should show minimal change and poor equivalence over time (ps ≤ .001), and raw scores demonstrated poor fits in models of within-person change (root mean square errors of approximation, RMSEAs > 0.12). Linear and equipercentile equating produced more similar means in reference groups (ps ≥ .09) and performed better in growth models (RMSEAs < 0.05). CONCLUSION Equipercentile equating is the preferred equating method because it accommodates tests more difficult than a reference test at different percentiles of performance and performs well in models of within-person trajectory. The method has broad applications in both clinical and research settings to enhance the ability to use nonequivalent test forms.
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Affiliation(s)
- Alden L Gross
- Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
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Moghekar A, Goh J, Li M, Albert M, O'Brien RJ. Cerebrospinal fluid Aβ and tau level fluctuation in an older clinical cohort. ACTA ACUST UNITED AC 2012; 69:246-50. [PMID: 22332192 DOI: 10.1001/archneurol.2011.732] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To determine whether cerebrospinal fluid (CSF) biomarkers for Alzheimer disease fluctuate significantly over time in a cohort of older, mildly symptomatic individuals. DESIGN Biomarker validation in a clinical cohort. SETTING University hospital inpatient unit. PARTICIPANTS Ten patients admitted for CSF drainage for diagnostic purposes. MAIN OUTCOME MEASURES The CSF levels of Aβ1-40, Aβ1-42, tau, and phosphorylated tau on threonine 181 (p-tau(181)) were measured every 6 hours for 24 or 36 hours. RESULTS The mean coefficient of variation values for each biomarker assessed in our 10 patients were 5.5% (95% CI, 3.8%-10.0%) for Aβ1-42, 12.2% (9.0%-24.2%) for Aβ1-40, 8.2% (5.7%-15.1%) for total tau, and 11.9% (8.5%-23.0%) for p-tau(181). These values are only slightly higher than the variability in the assay. In addition, no significant circadian fluctuation in any Alzheimer disease biomarker was observed given the limitations of our sampling frequency. CONCLUSION In a cohort of elderly patients, little fluctuation in the levels of important Alzheimer disease biomarkers in lumbar CSF is seen as a function of time.
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Affiliation(s)
- Abhay Moghekar
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
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Ances BM, Benzinger TL, Christensen JJ, Thomas J, Venkat R, Teshome M, Aldea P, Fagan AM, Holtzman DM, Morris JC, Clifford DB. 11C-PiB imaging of human immunodeficiency virus-associated neurocognitive disorder. ACTA ACUST UNITED AC 2012; 69:72-7. [PMID: 22232345 DOI: 10.1001/archneurol.2011.761] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To evaluate whether the amyloid-binding agent carbon 11-labeled Pittsburgh Compound B ((11)C-PiB) could differentiate Alzheimer disease (AD) from human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) in middle-aged HIV-positive participants. DESIGN (11)C-PiB scanning, clinical assessment, and cerebrospinal fluid (CSF) analysis were performed. Both χ(2) and t tests assessed differences in clinical and demographic variables between HIV-positive participants and community-living individuals observed at the Knight Alzheimer's Disease Research Center (ADRC). Analysis of variance assessed for regional differences in amyloid-β protein 1-42 (Aβ42) using (11)C-PiB. SETTING An ADRC and HIV clinic. PARTICIPANTS Sixteen HIV-positive participants (11 cognitively normal and 5 with HAND) and 19 ADRC participants (8 cognitively normal and 11 with symptomatic AD). MAIN OUTCOME MEASURES Mean and regional (11)C-PiB binding potentials. RESULTS Participants with symptomatic AD were older (P < .001), had lower CSF Aβ42 levels (P < .001), and had higher CSF tau levels (P < .001) than other groups. Regardless of degree of impairment, HIV-positive participants did not have increased (11)C-PiB levels. Mean and regional binding potentials were elevated for symptomatic AD participants (P < .001). CONCLUSIONS Middle-aged HIV-positive participants, even with HAND, do not exhibit increased (11)C-PiB levels, whereas symptomatic AD individuals have increased fibrillar Aβ42 deposition in cortical and subcortical regions. Observed dissimilarities between HAND and AD may reflect differences in Aβ42 metabolism. (11)C-PiB may provide a diagnostic biomarker for distinguishing symptomatic AD from HAND in middle-aged HIV-positive participants. Future cross-sectional and longitudinal studies are required to assess the utility of (11)C-PiB in older individuals with HAND.
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Affiliation(s)
- Beau M Ances
- Department of Neurology, Washington University in St. Louis, Campus Box 8111, 660 S Euclid Ave, St Louis, MO 63110, USA.
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Mild cognitive impairment in Parkinson disease: heterogenous mechanisms. J Neural Transm (Vienna) 2012; 120:157-67. [DOI: 10.1007/s00702-012-0771-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 01/29/2012] [Indexed: 10/28/2022]
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Ringman JM, Coppola G, Elashoff D, Rodriguez-Agudelo Y, Medina LD, Gylys K, Cummings JL, Cole GM. Cerebrospinal fluid biomarkers and proximity to diagnosis in preclinical familial Alzheimer's disease. Dement Geriatr Cogn Disord 2012; 33:1-5. [PMID: 22343824 PMCID: PMC3696356 DOI: 10.1159/000335729] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/09/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Biological markers of utility in tracking Alzheimer's disease (AD) during the presymptomatic prodromal phase are important for prevention studies. Changes in cerebrospinal fluid (CSF) levels of 42-amino-acid β-amyloid (Aβ(42)), total tau protein (t-tau) and phosphorylated tau at residue 181 (p-tau(181)) during this state are incompletely characterized. METHODS We measured CSF markers in 13 carriers of familial AD (FAD) mutations that are fully penetrant for causing AD (PSEN1 and APP) and in 5 non-mutation-carrying family members. RESULTS Even among the entirely presymptomatic mutation carriers (n = 9), Aβ(42) was diminished (388.7 vs. 618.4 pg/ml, p = 0.004), and t-tau (138.5 vs. 50.5 pg/ml, p = 0.002) and p-tau(181) (71.7 vs. 24.6 pg/ml, p = 0.003) were elevated. There was a negative correlation between Aβ(42) levels and age relative to the family-specific age of dementia diagnosis. CONCLUSIONS Our data are consistent with a decline in CSF Aβ(42) levels occurring at least 20 years prior to clinical dementia in FAD.
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Affiliation(s)
- John M. Ringman
- Mary S. Easton Center for Alzheimer's Disease Research at UCLA, Los Angeles, Calif., USA
| | - Giovanni Coppola
- Laboratory of Experimental Psychology, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | - David Elashoff
- Mary S. Easton Center for Alzheimer's Disease Research at UCLA, Los Angeles, Calif., USA
| | - Yaneth Rodriguez-Agudelo
- Laboratory of Experimental Psychology, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | - Luis D. Medina
- Mary S. Easton Center for Alzheimer's Disease Research at UCLA, Los Angeles, Calif., USA
| | - Karen Gylys
- Mary S. Easton Center for Alzheimer's Disease Research at UCLA, Los Angeles, Calif., USA
| | - Jeffrey L. Cummings
- Mary S. Easton Center for Alzheimer's Disease Research at UCLA, Los Angeles, Calif., USA
| | - Greg M. Cole
- Mary S. Easton Center for Alzheimer's Disease Research at UCLA, Los Angeles, Calif., USA
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CSF Biomarkers for Amyloid and Tau Pathology in Alzheimer's Disease. J Mol Neurosci 2011; 47:1-14. [DOI: 10.1007/s12031-011-9665-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 10/13/2011] [Indexed: 12/16/2022]
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