title: A targeted proteomic multiplex CSF assay identifies increased malate dehydrogenase and other neurodegenerative biomarkers in individuals with Alzheimer's disease pathology.
abstract: Alzheimer's disease (AD) is the most common cause of dementia. Biomarkers are required to identify individuals in the preclinical phase, explain phenotypic diversity, measure progression and estimate prognosis. The development of assays to validate candidate biomarkers is costly and time-consuming. Targeted proteomics is an attractive means of quantifying novel proteins in cerebrospinal and other fluids, and has potential to help overcome this bottleneck in biomarker development. We used a previously validated multiplexed 10-min, targeted proteomic assay to assess 54 candidate cerebrospinal fluid (CSF) biomarkers in two independent cohorts comprising individuals with neurodegenerative dementias and healthy controls. Individuals were classified as 'AD' or 'non-AD' on the basis of their CSF T-tau and amyloid Aβ1-42 profile measured using enzyme-linked immunosorbent assay; biomarkers of interest were compared using univariate and multivariate analyses. In all, 35/31 individuals in Cohort 1 and 46/36 in Cohort 2 fulfilled criteria for AD/non-AD profile CSF, respectively. After adjustment for multiple comparisons, five proteins were elevated significantly in AD CSF compared with non-AD CSF in both cohorts: malate dehydrogenase; total APOE; chitinase-3-like protein 1 (YKL-40); osteopontin and cystatin C. In an independent multivariate orthogonal projection to latent structures discriminant analysis (OPLS-DA), these proteins were also identified as major contributors to the separation between AD and non-AD in both cohorts. Independent of CSF Aβ1-42 and tau, a combination of these biomarkers differentiated AD and non-AD with an area under curve (AUC)=0.88. This targeted proteomic multiple reaction monitoring (MRM)-based assay can simultaneously and rapidly measure multiple candidate CSF biomarkers. Applying this technique to AD we demonstrate differences in proteins involved in glucose metabolism and neuroinflammation that collectively have potential clinical diagnostic utility.
authors.affiliation: Dementia Research Centre, Institute of Neurology, University College London, London, UK.
authors.forename: R W
authors.initials: RW
authors.lastname: Paterson
authors.affiliation: Centre for Translational Omics, Genetics and Genomic Medicine Programme, Institute of Child Health, University College London, London, UK.
authors.forename: W E
authors.initials: WE
authors.lastname: Heywood
authors.affiliation: Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Heslegrave
authors.affiliation: Lila Weston Institute, University College London Institute of Neurology, London, UK.
authors.forename: N K
authors.initials: NK
authors.lastname: Magdalinou
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden.
authors.forename: U
authors.initials: U
authors.lastname: Andreasson
authors.affiliation: Centre for Translational Omics, Genetics and Genomic Medicine Programme, Institute of Child Health, University College London, London, UK.
authors.forename: E
authors.initials: E
authors.lastname: Sirka
authors.affiliation: Centre for Translational Omics, Genetics and Genomic Medicine Programme, Institute of Child Health, University College London, London, UK.
authors.forename: E
authors.initials: E
authors.lastname: Bliss
authors.affiliation: Dementia Research Centre, Institute of Neurology, University College London, London, UK.
authors.forename: C F
authors.initials: CF
authors.lastname: Slattery
authors.affiliation: Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Toombs
authors.affiliation: Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|Department of Endocrinology, Skaraborg Central Hospital, Skövde, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Svensson
authors.affiliation: Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|Department of Neuropsychiatry, Skaraborg Central Hospital, Falköping, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Johansson
authors.affiliation: Dementia Research Centre, Institute of Neurology, University College London, London, UK.
authors.forename: N C
authors.initials: NC
authors.lastname: Fox
authors.affiliation: Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK.|Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital, Mölndal, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Zetterberg
authors.affiliation: Dementia Research Centre, Institute of Neurology, University College London, London, UK.|Centre for Translational Omics, Genetics and Genomic Medicine Programme, Institute of Child Health, University College London, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Mills
authors.affiliation: Dementia Research Centre, Institute of Neurology, University College London, London, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Schott
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D001057:Apolipoproteins E / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000134:cerebrospinal fluid*; D000071451:Chitinase-3-Like Protein 1 / Q000134:cerebrospinal fluid; D015331:Cohort Studies; D055316:Cystatin C / Q000134:cerebrospinal fluid; D005260:Female; D006801:Humans; D008291:Malate Dehydrogenase / Q000134:cerebrospinal fluid*; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D019636:Neurodegenerative Diseases / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D053495:Osteopontin / Q000134:cerebrospinal fluid; D011237:Predictive Value of Tests; D040901:Proteomics; D013223:Statistics as Topic; D013548:Sweden
chemical_list: D001057:Apolipoproteins E; D015415:Biomarkers; C084533:CHI3L1 protein, human; C525030:CST3 protein, human; D000071451:Chitinase-3-Like Protein 1; D055316:Cystatin C; C506895:SPP1 protein, human; D053495:Osteopontin; D008291:Malate Dehydrogenase