%0 Journal Article %J J Alzheimers Dis %D 2023 %T Diagnostic Performance of Cerebrospinal Fluid Neurofilament Light Chain and Soluble Amyloid-β Protein Precursor β in the Subcortical Small Vessel Type of Dementia. %A Axelsson Andrén, Elin %A Kettunen, Petronella %A Bjerke, Maria %A Rolstad, Sindre %A Zetterberg, Henrik %A Blennow, Kaj %A Wallin, Anders %A Svensson, Johan %X

BACKGROUND: The subcortical small vessel type of dementia (SSVD) is a common subtype of vascular dementia, but there is a lack of disease-specific cerebrospinal fluid (CSF) biomarkers.

OBJECTIVE: We investigated whether CSF concentrations of neurofilament light chain (NFL), soluble amyloid-β protein precursor α (sAβPPα), sAβPPβ, and CSF/serum albumin ratio could separate SSVD from healthy controls, Alzheimer's disease (AD), and mixed dementia (combined AD and SSVD).

METHODS: This was a mono-center study of patients with SSVD (n = 38), AD (n = 121), mixed dementia (n = 62), and controls (n = 96). The CSF biomarkers were measured using immunoassays, and their independent contribution to the separation between groups were evaluated using the Wald test. Then, the area under the receiver operating characteristics curve (AUROC) and 95% confidence intervals (CIs) were calculated.

RESULTS: Elevated neurofilament light chain (NFL) and decreased sAβPPβ independently separated SSVD from controls, and sAβPPβ also distinguished SSVD from AD and mixed dementia. The combination of NFL and sAβPPβ discriminated SSVD from controls with high accuracy (AUROC 0.903, 95% CI: 0.834-0.972). Additionally, sAβPPβ combined with the core AD biomarkers (amyloid-β42, total tau, and phosphorylated tau181) had a high ability to separate SSVD from AD (AUROC 0.886, 95% CI: 0.830-0.942) and mixed dementia (AUROC 0.903, 95% CI: 0.838-0.968).

CONCLUSIONS: The high accuracy of NFL and sAβPPβ to separate SSVD from controls supports that SSVD is a specific diagnostic entity. Moreover, SSVD was distinguished from AD and mixed dementia using sAβPPβ in combination with the core AD biomarkers.

%B J Alzheimers Dis %V 96 %P 1515-1528 %8 2023 Dec 05 %G eng %N 4 %R 10.3233/JAD-230680 %0 Journal Article %J J Alzheimers Dis %D 2021 %T Cerebrospinal Fluid Sulfatide Levels Lack Diagnostic Utility in the Subcortical Small Vessel Type of Dementia. %A Svensson, Johan %A Blomqvist, Maria %A Kettunen, Petronella %A Eckerström, Carl %A Henricsson, Marcus %A Jonsson, Michael %A Bjerke, Maria %A Månsson, Jan-Eric %A Wallin, Anders %X

BACKGROUND: Sulfatides (STs) in cerebrospinal fluid (CSF), as well as magnetic resonance imaging (MRI)-detected white matter hyperintensities (WMHs), may reflect demyelination. Here, we investigated the diagnostic utility of CSF ST levels in the subcortical small vessel type of dementia (SSVD), which is characterized by the presence of brain WMHs.

OBJECTIVE: To study the diagnostic utility of CSF ST levels in SSVD.

METHODS: This was a mono-center, cross-sectional study of SSVD (n = 16), Alzheimer's disease (n = 40), mixed dementia (n = 27), and healthy controls (n = 33). Totally, 20 ST species were measured in CSF by liquid chromatography-mass spectrometry (LC-MS/MS).

RESULTS: CSF total ST levels, as well as CSF levels of hydroxylated and nonhydroxylated ST species, did not differ across the study groups. In contrast, CSF neurofilament light chain (NFL) levels separated the patient groups from the controls. CSF total ST level correlated with CSF/serum albumin ratio in the total study population (r = 0.64, p <  0.001) and in all individual study groups. Furthermore, CSF total ST level correlated positively with MRI-estimated WMH volume in the total study population (r = 0.30, p <  0.05), but it did not correlate with CSF NFL level.

CONCLUSION: Although there was some relation between CSF total ST level and WMH volume, CSF ST levels were unaltered in all dementia groups compared to the controls. This suggests that CSF total ST level is a poor biomarker of demyelination in SSVD. Further studies are needed to investigate the mechanisms underlying the marked correlation between CSF total ST level and CSF/serum albumin ratio.

%B J Alzheimers Dis %V 82 %P 781-790 %8 2021 Jul 20 %G eng %N 2 %R 10.3233/JAD-201552 %0 Journal Article %J J Alzheimers Dis %D 2020 %T Dickkopf-1 Overexpression in vitro Nominates Candidate Blood Biomarkers Relating to Alzheimer's Disease Pathology. %A Shi, Liu %A Winchester, Laura M %A Liu, Benjamine Y %A Killick, Richard %A Ribe, Elena M %A Westwood, Sarah %A Baird, Alison L %A Buckley, Noel J %A Hong, Shengjun %A Dobricic, Valerija %A Kilpert, Fabian %A Franke, Andre %A Kiddle, Steven %A Sattlecker, Martina %A Dobson, Richard %A Cuadrado, Antonio %A Hye, Abdul %A Ashton, Nicholas J %A Morgan, Angharad R %A Bos, Isabelle %A Vos, Stephanie J B %A Ten Kate, Mara %A Scheltens, Philip %A Vandenberghe, Rik %A Gabel, Silvy %A Meersmans, Karen %A Engelborghs, Sebastiaan %A De Roeck, Ellen E %A Sleegers, Kristel %A Frisoni, Giovanni B %A Blin, Olivier %A Richardson, Jill C %A Bordet, Régis %A Molinuevo, José L %A Rami, Lorena %A Wallin, Anders %A Kettunen, Petronella %A Tsolaki, Magda %A Verhey, Frans %A Lleo, Alberto %A Alcolea, Daniel %A Popp, Julius %A Peyratout, Gwendoline %A Martínez-Lage, Pablo %A Tainta, Mikel %A Johannsen, Peter %A Teunissen, Charlotte E %A Freund-Levi, Yvonne %A Frölich, Lutz %A Legido-Quigley, Cristina %A Barkhof, Frederik %A Blennow, Kaj %A Rasmussen, Katrine Laura %A Nordestgaard, Børge Grønne %A Frikke-Schmidt, Ruth %A Nielsen, Sune Fallgaard %A Soininen, Hilkka %A Vellas, Bruno %A Kloszewska, Iwona %A Mecocci, Patrizia %A Zetterberg, Henrik %A Morgan, B Paul %A Streffer, Johannes %A Visser, Pieter Jelle %A Bertram, Lars %A Nevado-Holgado, Alejo J %A Lovestone, Simon %X

BACKGROUND: Previous studies suggest that Dickkopf-1 (DKK1), an inhibitor of Wnt signaling, plays a role in amyloid-induced toxicity and hence Alzheimer's disease (AD). However, the effect of DKK1 expression on protein expression, and whether such proteins are altered in disease, is unknown.

OBJECTIVE: We aim to test whether DKK1 induced protein signature obtained in vitro were associated with markers of AD pathology as used in the amyloid/tau/neurodegeneration (ATN) framework as well as with clinical outcomes.

METHODS: We first overexpressed DKK1 in HEK293A cells and quantified 1,128 proteins in cell lysates using aptamer capture arrays (SomaScan) to obtain a protein signature induced by DKK1. We then used the same assay to measure the DKK1-signature proteins in human plasma in two large cohorts, EMIF (n = 785) and ANM (n = 677).

RESULTS: We identified a 100-protein signature induced by DKK1 in vitro. Subsets of proteins, along with age and apolipoprotein E ɛ4 genotype distinguished amyloid pathology (A + T-N-, A+T+N-, A+T-N+, and A+T+N+) from no AD pathology (A-T-N-) with an area under the curve of 0.72, 0.81, 0.88, and 0.85, respectively. Furthermore, we found that some signature proteins (e.g., Complement C3 and albumin) were associated with cognitive score and AD diagnosis in both cohorts.

CONCLUSIONS: Our results add further evidence for a role of DKK regulation of Wnt signaling in AD and suggest that DKK1 induced signature proteins obtained in vitro could reflect theATNframework as well as predict disease severity and progression in vivo.

%B J Alzheimers Dis %V 77 %P 1353-1368 %8 2020 Sep 29 %G eng %N 3 %R 10.3233/JAD-200208 %0 Journal Article %J J Alzheimers Dis %D 2020 %T Validation of Plasma Proteomic Biomarkers Relating to Brain Amyloid Burden in the EMIF-Alzheimer's Disease Multimodal Biomarker Discovery Cohort. %A Westwood, Sarah %A Baird, Alison L %A Anand, Sneha N %A Nevado-Holgado, Alejo J %A Kormilitzin, Andrey %A Shi, Liu %A Hye, Abdul %A Ashton, Nicholas J %A Morgan, Angharad R %A Bos, Isabelle %A Vos, Stephanie J B %A Baker, Susan %A Buckley, Noel J %A Ten Kate, Mara %A Scheltens, Philip %A Teunissen, Charlotte E %A Vandenberghe, Rik %A Gabel, Silvy %A Meersmans, Karen %A Engelborghs, Sebastiaan %A De Roeck, Ellen E %A Sleegers, Kristel %A Frisoni, Giovanni B %A Blin, Olivier %A Richardson, Jill C %A Bordet, Régis %A Molinuevo, José L %A Rami, Lorena %A Wallin, Anders %A Kettunen, Petronella %A Tsolaki, Magda %A Verhey, Frans %A Lleo, Alberto %A Sala, Isabel %A Popp, Julius %A Peyratout, Gwendoline %A Martínez-Lage, Pablo %A Tainta, Mikel %A Johannsen, Peter %A Freund-Levi, Yvonne %A Frölich, Lutz %A Dobricic, Valerija %A Legido-Quigley, Cristina %A Bertram, Lars %A Barkhof, Frederik %A Zetterberg, Henrik %A Morgan, B Paul %A Streffer, Johannes %A Visser, Pieter Jelle %A Lovestone, Simon %X

We have previously investigated, discovered, and replicated plasma protein biomarkers for use to triage potential trials participants for PET or cerebrospinal fluid measures of Alzheimer's disease (AD) pathology. This study sought to undertake validation of these candidate plasma biomarkers in a large, multi-center sample collection. Targeted plasma analyses of 34 proteins with prior evidence for prediction of in vivo pathology were conducted in up to 1,000 samples from cognitively healthy elderly individuals, people with mild cognitive impairment, and in patients with AD-type dementia, selected from the EMIF-AD catalogue. Proteins were measured using Luminex xMAP, ELISA, and Meso Scale Discovery assays. Seven proteins replicated in their ability to predict in vivo amyloid pathology. These proteins form a biomarker panel that, along with age, could significantly discriminate between individuals with high and low amyloid pathology with an area under the curve of 0.74. The performance of this biomarker panel remained consistent when tested in apolipoprotein E ɛ4 non-carrier individuals only. This blood-based panel is biologically relevant, measurable using practical immunocapture arrays, and could significantly reduce the cost incurred to clinical trials through screen failure.

%B J Alzheimers Dis %V 74 %P 213-225 %8 2020 %G eng %N 1 %1 https://www.ncbi.nlm.nih.gov/pubmed/31985466?dopt=Abstract %R 10.3233/JAD-190434 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Update on Vascular Cognitive Impairment Associated with Subcortical Small-Vessel Disease. %A Wallin, Anders %A Román, Gustavo C %A Esiri, Margaret %A Kettunen, Petronella %A Svensson, Johan %A Paraskevas, George P %A Kapaki, Elisabeth %K Animals %K Cerebrovascular Disorders %K Dementia %K Humans %X

Subcortical small-vessel disease (SSVD) is a disorder well characterized from the clinical, imaging, and neuropathological viewpoints. SSVD is considered the most prevalent ischemic brain disorder, increasing in frequency with age. Vascular risk factors include hypertension, diabetes, hyperlipidemia, elevated homocysteine, and obstructive sleep apnea. Ischemic white matter lesions are the hallmark of SSVD; other pathological lesions include arteriolosclerosis, dilatation of perivascular spaces, venous collagenosis, cerebral amyloid angiopathy, microbleeds, microinfarcts, lacunes, and large infarcts. The pathogenesis of SSVD is incompletely understood but includes endothelial changes and blood-brain barrier alterations involving metalloproteinases, vascular endothelial growth factors, angiotensin II, mindin/spondin, and the mammalian target of rapamycin pathway. Metabolic and genetic conditions may also play a role but hitherto there are few conclusive studies. Clinical diagnosis of SSVD includes early executive dysfunction manifested by impaired capacity to use complex information, to formulate strategies, and to exercise self-control. In comparison with Alzheimer's disease (AD), patients with SSVD show less pronounced episodic memory deficits. Brain imaging has advanced substantially the diagnostic tools for SSVD. With the exception of cortical microinfarcts, all other lesions are well visualized with MRI. Diagnostic biomarkers that separate AD from SSVD include reduction of cerebrospinal fluid amyloid-β (Aβ)42 and of the ratio Aβ42/Aβ40 often with increased total tau levels. However, better markers of small-vessel function of intracerebral blood vessels are needed. The treatment of SSVD remains unsatisfactory other than control of vascular risk factors. There is an urgent need of finding targets to slow down and potentially halt the progression of this prevalent, but often unrecognized, disorder.

%B J Alzheimers Dis %V 62 %P 1417-1441 %8 2018 %G eng %U https://content.iospress.com/download/journal-of-alzheimers-disease/jad170803?id=journal-of-alzheimers-disease%2Fjad170803 %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/29562536?dopt=Abstract %R 10.3233/JAD-170803 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Reduced Cerebrospinal Fluid Concentration of Apolipoprotein A-I in Patients with Alzheimer's Disease. %A Johansson, Per %A Almqvist, Erik G %A Bjerke, Maria %A Wallin, Anders %A Johansson, Jan-Ove %A Andreasson, Ulf %A Blennow, Kaj %A Zetterberg, Henrik %A Svensson, Johan %X

BACKGROUND: Apolipoprotein E (ApoE) has been extensively studied in Alzheimer's disease (AD), but little is known of apolipoprotein A-I (ApoA-I) in cerebrospinal fluid (CSF).

OBJECTIVE: Plasma lipids as well as ApoA-I and ApoE in plasma and CSF were determined and related to Mini-Mental State Examination (MMSE) score, APOE genotype, and CSF AD biomarkers.

METHODS: Consecutive patients with AD (n = 29), stable mild cognitive impairment (n = 13), other dementias (n = 14), and healthy controls (n = 18) were included at a single center.

RESULTS: AD patients had higher plasma triglycerides and lower CSF ApoA-I concentration than controls (both p < 0.05). CSF ApoE concentration was reduced in other dementias (p < 0.01). In AD as well as other dementias, the ratios between CSF and plasma concentrations of both ApoA-I and ApoE were lower than those in the controls. ApoA-I and ApoE in plasma and CSF were not influenced by APOEɛ4 allele distribution. In the total study population (n = 74), CSF ApoA-I correlated positively with MMSE score (r = 0.26, p < 0.05) and negatively with CSF P-tau (r = -0.25, p < 0.05). CSF ApoE correlated positively with CSF concentrations of T-tau and P-tau in the total study population and in AD patients.

CONCLUSION: CSF ApoA-I was reduced in AD patients and associated with measures of cognitive function and AD disease status. The mechanisms underlying the decreased CSF:plasma ratios of ApoA-I and ApoE in AD and other dementias need to be explored in further studies.

%B J Alzheimers Dis %V 59 %P 1017-1026 %8 2017 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/28697566?dopt=Abstract %R 10.3233/JAD-170226 %0 Journal Article %J J Alzheimers Dis %D 2016 %T A Genetic Variant of the Sortilin 1 Gene is Associated with Reduced Risk of Alzheimer's Disease. %A Andersson, Carl-Henrik %A Hansson, Oskar %A Minthon, Lennart %A Andreasen, Niels %A Blennow, Kaj %A Zetterberg, Henrik %A Skoog, Ingmar %A Wallin, Anders %A Nilsson, Staffan %A Kettunen, Petronella %X

Alzheimer's disease (AD) is a neurodegenerative disorder represented by the accumulation of intracellular tau protein and extracellular deposits of amyloid-β (Aβ) in the brain. The gene sortilin 1 (SORT1) has previously been associated with cardiovascular disease in gene association studies. It has also been proposed to be involved in AD pathogenesis through facilitating Aβ clearance by binding apoE/Aβ complexes prior to cellular uptake. However, the neuropathological role of SORT1 in AD is not fully understood. To evaluate the associations between gene variants of SORT1 and risk of AD, we performed genetic analyses in a Swedish case-control cohort. Ten single nucleotide polymorphisms (SNPs), covering the whole SORT1 gene, were selected and genotyped in 620 AD patients and 1107 controls. The SNP rs17646665, located in a non-coding region of the SORT1 gene, remained significantly associated with decreased risk of AD after multiple testing (pc = 0.0061). In addition, other SNPs were found to be nominally associated with risk of AD, as well as altered cognitive function and the CSF biomarker Aβ42, but these associations did not survive correction for multiple testing. The fact that SORT1 has been strongly associated with risk of cardiovascular disease is intriguing as cardiovascular disease is also regarded as a risk factor for AD. Finally, increased knowledge about SORT1 function has a potential to increase our understanding of APOE, the strongest risk factor for AD.

%B J Alzheimers Dis %V 53 %P 1353-63 %8 2016 Jul 01 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/27392867?dopt=Abstract %R 10.3233/JAD-160319