Abstract
Emerging plasma biomarkers of Alzheimer's disease might be non-invasive tools to trace early Alzheimer's disease-related abnormalities such as the accumulation of amyloid-beta peptides, ...neurofibrillary tau tangles, glial activation and neurodegeneration. It is, however, unclear which pathological processes in the CNS can be adequately detected by peripheral measurements and whether plasma biomarkers are equally applicable in both clinical and preclinical phases. Here we aimed to explore the timing and performance of plasma biomarkers in mutation carriers compared to non-carriers in autosomal dominant Alzheimer's disease.
Samples (n = 164) from mutation carriers (n = 33) and non-carriers (n = 42) in a Swedish cohort of autosomal dominant Alzheimer's disease (APP p.KM670/671NL, APP p.E693G and PSEN1 p.H163Y) were included in explorative longitudinal analyses. Plasma phosphorylated tau (P-tau181), total tau (T-tau), neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) concentrations were measured with a single-molecule array method as previously described. Plasma biomarkers were additionally correlated to Alzheimer's disease core biomarkers in the CSF.
Results from the longitudinal analyses confirmed that plasma P-tau181, NfL and GFAP concentrations were higher in mutation carriers compared to non-carriers. This change was observed in the presymptomatic phase and detectable first as an increase in GFAP approximately 10 years before estimated symptom onset, followed by increased levels of P-tau181 and NfL closer to expected onset. Plasma P-tau181 levels were correlated to levels of P-tau181 and T-tau in the CSF.
Altogether, plasma P-tau181, GFAP and NfL seem to be feasible biomarkers to detect different Alzheimer's disease-related pathologies already in presymptomatic individuals. Interestingly, changes in plasma GFAP concentrations were detected prior to P-tau181 and NfL. Our results suggest that plasma GFAP might reflect Alzheimer's disease pathology upstream to accumulation of tangles and neurodegeneration. The implications of these findings need additional validation, in particular because of the limited sample size.
Johansson et al. describe plasma biomarkers in a longitudinal Swedish cohort of patients with monogenic Alzheimer’s disease. Plasma GFAP began to increase 10 years before symptom onset, prior to P-tau181 and NfL, suggesting that GFAP is mirroring Alzheimer’s disease pathology upstream of tau phosphorylation and neurodegeneration.
Studying autosomal dominant Alzheimer's disease (ADAD), caused by gene mutations yielding nearly complete penetrance and a distinct age of symptom onset, allows investigation of presymptomatic ...pathological processes that can identify a therapeutic window for disease-modifying therapies. Astrocyte activation may occur in presymptomatic Alzheimer's disease (AD) because reactive astrocytes surround β-amyloid (Aβ) plaques in autopsy brain tissue. Positron emission tomography was performed to investigate fibrillar Aβ, astrocytosis and cerebral glucose metabolism with the radiotracers (11)C-Pittsburgh compound-B (PIB), (11)C-deuterium-L-deprenyl (DED) and (18)F-fluorodeoxyglucose (FDG) respectively in presymptomatic and symptomatic ADAD participants (n = 21), patients with mild cognitive impairment (n = 11) and sporadic AD (n = 7). Multivariate analysis using the combined data from all radiotracers clearly separated the different groups along the first and second principal components according to increased PIB retention/decreased FDG uptake (component 1) and increased DED binding (component 2). Presymptomatic ADAD mutation carriers showed significantly higher PIB retention than non-carriers in all brain regions except the hippocampus. DED binding was highest in presymptomatic ADAD mutation carriers. This suggests that non-fibrillar Aβ or early stage plaque depostion might interact with inflammatory responses indicating astrocytosis as an early contributory driving force in AD pathology. The novelty of this finding will be investigated in longitudinal follow-up studies.
Highlights • We analysed data on fatal poisoning in drug addicts in 2012 from five Nordic countries. • Differences in death rate among fatal poisoned drug addicts diminished between the countries ...compared to earlier studies. • Opioids were the main cause of death among fatal poisoned drug addicts in all countries. • Medicinal opioids had mainly replaced heroin/morphine. • New psychoactive substances emerged.
•Finland had a different drug profile compared to the other countries.•Opioids were the main cause of death among fatal poisoned drug addicts in all countries.•Cocaine and MDMA deaths increased in ...all countries.•Sweden saw a high number of deaths from fentanyl analogues.•New psychoactive substances have emerged in all countries except Iceland.
This study is the seventh report on fatal poisonings among drug addicts in the Nordic countries. In this report, we analyse data from the five Nordic countries: Denmark, Finland, Iceland, Norway and Sweden. Data on gender, number of deaths, places of deaths, age, main intoxicants and substances detected in blood were recorded to obtain national and comparable Nordic data, and to allow comparison with earlier studies conducted in 1984, 1991, 1997, 2002, 2007 and 2012.
The death rate (number of deaths per 100,000 inhabitants) was highest in Iceland (6.58) followed closely by Sweden (6.46) and then lowest in Denmark (4.29). The death rate increased in Finland (5.84), Iceland and Sweden and decreased in Denmark compared to earlier studies. The death rate in Norway, which has decreased since 2002, has stabilised around 5.7 as of 2017. Women accounted for 7–23% of the fatal poisonings. The percentage was lowest in Iceland and highest in Finland and Norway. The age range was 14–70 years. The median age (41 years) was highest in Denmark and Norway. The other countries had a median age between 33 and 35 years.
Opioids were the main cause of death. Methadone remained the main intoxicant in Denmark, while heroin/morphine was still the main intoxicant in Norway, as was buprenorphine in Finland. However, the picture has changed in Sweden compared to 2012, where heroin/morphine caused most deaths in 2017. Sweden also experienced the highest number of deaths from fentanyl analogues (67 deaths) and buprenorphine (61 deaths). Deaths from fentanyl analogues also occurred in Denmark, Finland and Norway, but to a smaller extent. Over the years, the proportion of opioid deaths has decreased in all countries except Sweden, which has experienced an increase. This decline has been replaced by deaths from CNS stimulants like cocaine, amphetamine and methylenedioxymethamphetamine (MDMA). Cocaine deaths have occurred in all countries but most frequently in Denmark. MDMA deaths have increased in all countries but mostly in Finland.
Poly-drug use was widespread, as seen in the earlier studies. The median number of detected drugs per case varied from 4–6. Heroin/morphine, methadone, buprenorphine, cocaine, amphetamine, methamphetamine, MDMA, tetrahydrocannabinol (THC) and benzodiazepines were frequently detected. Pregabalin and gabapentin were detected in all countries, especially pregabalin, which was detected in 42% of the Finnish cases. New psychoactive substances (NPS) occurred in all countries except Iceland.
Abstract The frequency of medico-legally examined fatal poisonings in 2007 among drug addicts was investigated in five Nordic countries; Denmark, Finland, Iceland, Norway, and Sweden. The number of ...deaths, age, sex, place of death, main intoxicant, and other drugs present in blood samples were recorded to obtain national and comparable Nordic data, as well as data to compare with earlier studies in 2002, 1997, and 1991. Norway had the highest incidence of drug addict deaths by poisoning followed by Denmark, with 8.24 and 6.92 per 100,000 inhabitants, respectively. The death rates in Finland (4.02), Iceland (4.56), and Sweden (3.53) were about half that of Norway and Denmark. Compared with earlier studies, the death rates were unchanged in Denmark and Norway, but increased in Finland, Iceland, and Sweden. In all countries, fewer deaths (29–35%) were recorded in the capital area compared with earlier studies. Females accounted for 11–19% of the fatal poisonings. Iceland deviates with a more equal distribution between men and women (40%). Deaths from methadone overdoses increased in all Nordic countries, and methadone was the main intoxicant in Denmark in 2007, accounting for 51% of the poisonings. In Norway and Sweden, heroin/morphine was still the main intoxicant with a frequency of 68% and 48%, respectively. In Iceland, 3 deaths each were due to heroin/morphine and methadone, respectively. Finland differs from other Nordic countries in having a high number of poisonings caused by buprenorphine and very few caused by heroin/morphine. The total number of buprenorphine deaths in Finland doubled from 16 in 2002 to 32 in 2007, where it constituted 25% of deaths. The general toxicological screening program showed widespread multi-drug use in all countries. The median number of drugs per case varied from 3 to 5. The most frequently detected substances were heroin/morphine, methadone, buprenorphine, tramadol, amphetamine, cocaine, tetrahydrocannabinol, benzodiazepines and ethanol.
Background
Familial Alzheimer's disease (FAD) resulting from gene mutations in PSEN1, PSEN2 and APP is associated with changes in the brain.
Objective
The aim of this study was to investigate changes ...in grey matter (GM), white matter (WM) and the cerebrospinal fluid (CSF) in FAD.
Subjects
Ten mutation carriers (MCs) with three different mutations in PSEN1 and APP and 20 noncarriers (NCs) were included in the study. Three MCs were symptomatic and seven were presymptomatic (pre‐MCs).
Methods
Whole‐brain GM volume as well as fractional anisotropy (FA) and mean diffusivity (MD) using voxel‐based morphometry and tract‐based spatial statistics analyses, respectively, were compared between MCs and NCs. FA and MD maps were obtained from diffusion tensor imaging.
Results
A significant increase in MD was found in the left inferior longitudinal fasciculus, cingulum and bilateral superior longitudinal fasciculus in pre‐MCs compared with NCs. After inclusion of the three symptomatic MCs in the analysis, the regions became wider. The mean MD of these regions showed significant negative correlation with the CSF level of Aβ42, and positive correlations with P‐tau181p and T‐tau. No differences were observed in GM volume and FA between the groups.
Conclusions
The results of this study suggest that FAD gene mutations affect WM diffusivity before changes in GM volume can be detected. The WM changes observed were related to changes in the CSF, with similar patterns previously observed in sporadic Alzheimer's disease.
Activation of Complement Following Total Hip Replacement Thordardottir, S.; Vikingsdottir, T.; Bjarnadottir, H. ...
Scandinavian journal of immunology,
March 2016, 2016-Mar, 2016-03-00, 20160301, Letnik:
83, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The aim of this study was to investigate whether complement activation, via the classical and alternative pathways, occurs following a cemented total hip replacement (THR) surgery due to ...osteoarthritis. Blood samples were collected systematically from 12 patients – six male and six women, with a median age of 75 (range: 59–90 years) – preoperatively, 6 h post‐operatively and on the first, second and third post‐operative day. Total function of classical (CH50) and alternative pathways (AH50) was evaluated, along with the determination of serum concentrations of the complement proteins C3, C4, C3d, the soluble terminal complement complex (sTCC) sC5b‐9, as well as C‐reactive protein (CRP) and albumin. Measurements of CRP and albumin levels elucidated a marked inflammatory response following the operation. The CH50, AH50 and C3 and C4 levels were significantly lower 6 h after the surgery compared with the preoperative levels, but elevated above the preoperative levels during the following 3 days. The complement activation product C3d levels increased continually during the whole observation period, from 13.5 AU/ml (range: 8–19 AU/ml) preoperative to 20 AU/ml (range: 12–34 AU/ml) on the third post‐operative day. Furthermore, we observed an increase in the sC5b‐9 levels between the preoperative and the third post‐operative day. These results demonstrate a significant activation of the complement system following cemented THR. Further studies are needed to elucidate the time frame and the pathogenic role of this observed complement activation.
Alzheimer disease (AD) is a progressive neurodegenerative disorder and the most common form of dementia. The majority of AD cases are sporadic, while up to 5% are families with an early onset AD ...(EOAD). Mutations in one of the three genes: amyloid beta precursor protein (APP), presenilin 1 (PSEN1) or presenilin 2 (PSEN2) can be disease causing. However, most EOAD families do not carry mutations in any of these three genes, and candidate genes, such as the sortilin-related receptor 1 (SORL1), have been suggested to be potentially causative. To identify AD causative variants, we performed whole-exome sequencing on five individuals from a family with EOAD and a missense variant, p.Arg1303Cys (c.3907C > T) was identified in SORL1 which segregated with disease and was further characterized with immunohistochemistry on two post mortem autopsy cases from the same family. In a targeted re-sequencing effort on independent index patients from 35 EOAD-families, a second SORL1 variant, c.3050-2A > G, was found which segregated with the disease in 3 affected and was absent in one unaffected family member. The c.3050-2A > G variant is located two nucleotides upstream of exon 22 and was shown to cause exon 22 skipping, resulting in a deletion of amino acids Gly1017- Glu1074 of SORL1. Furthermore, a third SORL1 variant, c.5195G > C, recently identified in a Swedish case control cohort included in the European Early-Onset Dementia (EU EOD) consortium study, was detected in two affected siblings in a third family with familial EOAD. The finding of three SORL1-variants that segregate with disease in three separate families with EOAD supports the involvement of SORL1 in AD pathology. The cause of these rare monogenic forms of EOAD has proven difficult to find and the use of exome and genome sequencing may be a successful route to target them.
Disturbed amyloid precursor protein (APP) processing is considered to be central to the pathogenesis of Alzheimer's disease (AD). The autosomal dominant form of the disease, familial AD (FAD), may ...serve as a model for the sporadic form of AD. In FAD the diagnosis of AD is reliable and presymptomatic individuals carrying FAD mutations can give valuable insights into the earliest stages of the disease where therapeutic interventions are thought to be the most effective.
In the current cross-sectional study, products of APP processing (e.g., sAPPα, sAPPβ, Aβ
, Aβ
and Aβ
) were measured in the cerebrospinal fluid (CSF) of individuals carrying one of three FAD mutations, APPswe (p.KM670/671NL), APParc (p.E693G) and PSEN1 (p.H163Y), as well as in non-mutation carriers from the same families.
We observed pathological APP processing in presymptomatic carriers of FAD mutations, with different profiles of APP and Aβ isoforms in the three mutation carrier groups, APPswe (p.KM670/671NL), APParc (p.E693G) and PSEN1 (p.H163Y), except for the well-established decrease in CSF Aβ
that was found with all mutations.
These findings add to the current evidence that AD pathophysiology differs between disease-causing mutations and can be monitored in the presymptomatic disease stage by CSF analyses. This may also be important from a therapeutic standpoint, by opening a window to monitor effects of disease-modifying drugs on AD pathophysiology.
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