Diagnostic value of plasma p-tau181, NfL, and GFAP in a clinical setting cohort of prevalent neurodegenerative dementias.

BACKGROUND: Increasing evidence supports the use of plasma biomarkers of neurodegeneration and neuroinflammation to screen and diagnose patients with dementia. However, confirmatory studies are required to demonstrate their usefulness in the clinical setting. METHODS: We evaluated plasma and cerebrospinal fluid (CSF) samples from consecutive patients with frontotemporal dementia (FTD) (n = 59), progressive supranuclear palsy (PSP) (n = 31), corticobasal syndrome (CBS) (n = 29), dementia with Lewy bodies (DLB) (n = 49), Alzheimer disease (AD) (n = 97), and suspected non-AD physiopathology (n = 51), as well as plasma samples from 60 healthy controls (HC). We measured neurofilament light chain (NfL), phospho-tau181 (p-tau181), and glial fibrillary acid protein (GFAP) using Simoa (all plasma biomarkers and CSF GFAP), CLEIA (CSF p-tau181), and ELISA (CSF NfL) assays. Additionally, we stratified patients according to the A/T/N classification scheme and the CSF α-synuclein real-time quaking-induced conversion assay (RT-QuIC) results. RESULTS: We found good correlations between CSF and plasma biomarkers for NfL (rho = 0.668, p < 0.001) and p-tau181 (rho = 0.619, p < 0.001). Plasma NfL was significantly higher in disease groups than in HC and showed a greater increase in FTD than in AD [44.9 (28.1-68.6) vs. 21.9 (17.0-27.9) pg/ml, p < 0.001]. Conversely, plasma p-tau181 and GFAP levels were significantly higher in AD than in FTD [3.2 (2.4-4.3) vs. 1.1 (0.7-1.6) pg/ml, p < 0.001; 404.7 (279.7-503.0) vs. 198.2 (143.9-316.8) pg/ml, p < 0.001]. GFAP also allowed discriminating disease groups from HC. In the distinction between FTD and AD, plasma p-tau181 showed better accuracy (AUC 0.964) than NfL (AUC 0.791) and GFAP (AUC 0.818). In DLB and CBS, CSF amyloid positive (A+) subjects had higher plasma p-tau181 and GFAP levels than A- individuals. CSF RT-QuIC showed positive α-synuclein seeding activity in 96% DLB and 15% AD patients with no differences in plasma biomarker levels in those stratified by RT-QuIC result. CONCLUSIONS: In a single-center clinical cohort, we confirm the high diagnostic value of plasma p-tau181 for distinguishing FTD from AD and plasma NfL for discriminating degenerative dementias from HC. Plasma GFAP alone differentiates AD from FTD and neurodegenerative dementias from HC but with lower accuracy than p-tau181 and NfL. In CBS and DLB, plasma p-tau181 and GFAP levels are significantly influenced by beta-amyloid pathology.

Dementia-related genetic variants in an Italian population of early-onset Alzheimer's disease.

Early-onset Alzheimer's disease (EOAD) is the most common form of early-onset dementia. Although three major genes have been identified as causative, the genetic contribution to the disease remains unsolved in many patients. Recent studies have identified pathogenic variants in genes representing a risk factor for developing Alzheimer's disease (AD) and in causative genes for other degenerative dementias as responsible for EOAD. To study them further, we investigated a panel of candidate genes in 102 Italian EOAD patients, 45.10% of whom had a positive family history and 21.74% with a strong family history of dementia. We found that 10.78% of patients carried pathogenic or likely pathogenic variants, including a novel variant, in PSEN1, PSEN2, or APP, and 7.84% showed homozygosity for the ε4 APOE allele. Additionally, 7.84% of patients had a moderate risk allele in PSEN1, PSEN2, or TREM2 genes. Besides, we observed that 12.75% of our patients carried only a variant in genes associated with other neurodegenerative diseases. The combination of these variants contributes to explain 46% of cases with a definite familiarity and 32% of sporadic forms. Our results confirm the importance of extensive genetic screening in EOAD for clinical purposes, to select patients for future treatments and to contribute to the definition of overlapping pathogenic mechanisms between AD and other forms of dementia.

Risk of SARS-CoV-2 infection, hospitalization and death for COVID-19 in people with Parkinson's disease or parkinsonism over a 15-month period: a cohort study.

BACKGROUND: The patterns of long term risk of SARS-CoV-2 infection, hospitalization for COVID-19 and related death are uncertain in people with Parkinson's disease (PD) or parkinsonism (PS). The aim of the study was to quantify these risks compared to a control population cohort, during the period March 2020-May 2021, in Bologna, northern Italy. METHOD: ParkLink Bologna cohort (759 PD; 192 PS) and controls (9,226) anonymously matched (ratio 1:10) for sex, age, district, comorbidity were included. Data were analysed in the whole period and in the two different pandemic waves (March-May 2020 and October 2020-May 2021). RESULTS: Adjusted hazard ratio of SARS-CoV-2 infection was 1.3 (95% CI 1.04-1.7) in PD and 1.9 (1.3-2.8) in PS compared to the controls. The trend was detected in both the pandemic waves. Adjusted hazard ratio of hospitalization for COVID-19 was 1.1 (95% CI 0.8-1.7) in PD and 1.8 (95% CI 0.97-3.1) in PS. A higher risk of hospital admission was detected in PS only in the first wave. The 30-day mortality risk after hospitalization was higher (p=0.048) in PS (58%) than in PD (19%) and controls (26%). CONCLUSIONS: Compared with controls, after adjustment for key covariates, people with PD and PS showed a higher risk of SARS-CoV-2 infection throughout the first 15 months of the pandemic. COVID-19 hospitalization risk was increased only in people with PS and only during the first wave. This group of patients was burdened by a very high risk of death after infection and hospitalization.

The Effect of Curcumin on Idiopathic Parkinson Disease: A Clinical and Skin Biopsy Study.

There are currently no standardized therapies for Parkinson disease (PD). Curcumin shows anti-amyloidogenic properties in vitro and may be a promising treatment for PD. We evaluated the effects of curcumin supplementation on clinical scales and misfolded, phosphorylated α-synuclein (p-syn) accumulation in skin biopsies in 19 PD patients who received curcumin supplementation for 12 months and 14 PD patients to treated with curcumin. The patients underwent autonomic (COMPASS-31), motor (MDS-UPDRS and H&Y) and nonmotor (NMSS) questionnaires and skin biopsies to evaluate clinical involvement and p-syn load in skin nerves at the beginning and the end of study. Curcumin and curcuminoid levels were assayed in plasma and CSF. Supplemented patients showed detectable CSF curcuminoid levels that were lower than those in plasma. They showed a decrease of COMPASS-31 and NMSS scores, and a slight p-syn load decrease versus untreated patients who displayed a worsening of these parameters despite increased levodopa doses. Multiple regression models showed a significant effect of curcumin supplementation in decreasing the worsening of the clinical parameters and p-syn load at after curcumin treatment. These data suggest that curcumin can cross the blood-brain barrier, that it is effective in ameliorating clinical parameters and that it shows a tendency to decrease skin p-syn accumulation in PD patients.

Premotor antidepressants use differs according to Parkinson's disease subtype: A cohort study.

BACKGROUND: Depression is more frequently associated with akinetic-rigid/postural instability gait difficulty subtypes of Parkinson's disease than with tremor-dominant subtype. OBJECTIVES: The aim of the study is to investigate the frequency of exposure to antidepressant drugs, as proxy of depression, before motor onset according to Parkinson's disease subtypes. METHOD: Based on a historical cohort design, the exposure to antidepressant drugs before Parkinson's disease motor onset was obtained from the drug prescription database and assessed in the resident population of the Local Healthcare Trust of Bologna (443,117 subjects older than 35 years). Diagnosis of Parkinson's disease and subtype (tremor dominant, non-tremor dominant) at onset were recorded by neurologists and obtained from the "ParkLink Bologna" record linkage system. Exposure to antidepressants was compared both to the general population and between the two subtypes. RESULTS: From 2006 to 2018, 198 patients had a tremor dominant subtype at onset whereas 450 did not. Comparison with the general population for antidepressant exposure showed an adjusted hazard ratio of 0.86 (95% CI 0.44-1.70) for the tremor dominant subtype and 1.66 (1.16-2.39) for the non-tremor dominant subtype. Comparison of non-tremor dominant with tremor dominant subtypes showed an adjusted odds ratio of 1.86 (1.05-3.95) for antidepressant exposure. CONCLUSIONS: In our study, non-tremor dominant Parkinson's disease at onset was significantly associated with exposure to antidepressants in comparison to the general population and in comparison with the tremor dominant subtype. These results support the hypothesis of different biological substrates for different Parkinson's disease subtypes even before motor onset.

The Combination of Metabolic Posterior Cingulate Cortical Abnormalities and Structural Asymmetries Improves the Differential Diagnosis Between Primary Progressive Aphasia and Alzheimer's Disease.

Differential diagnosis between primary progressive aphasia (PPA) and Alzheimer's disease (AD) could be difficult if based on clinical grounds alone. We evaluated the combination of proton MR spectroscopy of posterior cingulate cortex (PCC) and quantitative structural imaging asymmetries to differentiate PPA from AD patients. A greater left-lateralized temporo-parietal atrophy (higher accuracy for the PCC, 81.4%) and metabolic neurodegenerative changes in PCC (accuracy 76.8%) was demonstrated in PPA versus AD. The combined multiparametric approach increased the accuracy to 94%in the differential diagnosis between these two neurodegenerative diseases.

Long-term persistence of NMDAR antibodies after encephalitis with de novo occurrence of demyelinating disorder.

The issue of persistence of NMDAR antibodies after encephalitis is not fully elucidated and their relationship with demyelinating disorders has been suggested. A female patient showed at the age of 18 an acute neurological disorder (with psychiatric symptoms, focal seizures, orofacial dyskinesias and hypoventilation requiring ventilatory support) clinically mimicking anti-NMDAR encephalitis. At that time specific laboratory tests were not available, CSF revealed oligoclonal bands and MRI was negative. The patient had full recovery after first line immunotherapy (i.v. steroids and immunoglobulins). Fifteen years later, at the age of 33, she was hospitalized with subacute right hemiparesis and MRI disclosed multiple T2 hyperintensities in the white matter, one of them in the left midbrain showing contrast enhancement. Serum and CSF NMDAR antibodies were positive while MOG and AQP4 antibodies were negative. Intravenous methylprednisolone led to complete recovery. This case report provides evidence of a long-term persistence of NMDAR antibodies even 15 years after the encephalitis and raises the suspicion of a possible causal relationship between NMDAR antibodies and demyelinating disorders in the form of multiple sclerosis.

Risk of Hospitalization and Death for COVID-19 in People with Parkinson's Disease or Parkinsonism.

BACKGROUND: The risk of COVID-19 and related death in people with Parkinson's disease or parkinsonism is uncertain. The aim of the study was to assess the risk of hospitalization for COVID-19 and death in a cohort of patients with Parkinson's disease or parkinsonism compared with a control population cohort, during the epidemic bout (March-May 2020) in Bologna, northern Italy. METHODS: Participants of the ParkLink study with the clinical diagnosis of Parkinson's disease or parkinsonism and people anonymously matched (ratio 1:10) for sex, age, district, and Charlson Index were included. The hospital admission rate for COVID-19 (February 26-May 31, 2020) and the death rate for any cause were the outcomes of interest. RESULTS: The ParkLink cohort included 696 subjects with Parkinson's disease and 184 with parkinsonism, and the control cohort had 8590 subjects. The 3-month hospitalization rate for COVID-19 was 0.6% in Parkinson's disease, 3.3% in parkinsonism, and 0.7% in controls. The adjusted hazard ratio (age, sex, district, Charlson Index) was 0.8 (95% CI, 0.3-2.3, P = 0.74) in Parkinson's disease and 3.3 (1.4-7.6, P = 0.006) in parkinsonism compared with controls. Twenty-nine of the infected subjects died; 30-day fatality rate was 35.1%, without difference among the 3 groups. Six of 10 Parkinson's disease/parkinsonism patients had the infection during hospitalization or in a nursing home. CONCLUSIONS: Parkinson's disease per se probably is not a risk factor for COVID-19 hospitalization. Conversely, parkinsonism is an independent risk factor probably because of a more severe health status, entailing higher care dependence and placement in high-infection-risk accommodations. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Identification of rare genetic variants in Italian patients with dementia by targeted gene sequencing.

Genetics is intricately involved in the etiology of neurodegenerative dementias. The incidence of monogenic dementia among all neurodegenerative forms is unknown due to the lack of systematic studies and of patient/clinician access to extensive diagnostic procedures. In this study, we conducted targeted sequencing in 246 clinically heterogeneous patients, mainly with early-onset and/or familial neurodegenerative dementia, using a custom-designed next-generation sequencing panel covering 27 genes known to harbor mutations that can cause different types of dementia, in addition to the detection of C9orf72 repeat expansions. Forty-nine patients (19.9%) carried known pathogenic or novel, likely pathogenic, variants, involving both common (presenilin 1, presenilin 2, C9orf72, and granulin) and rare (optineurin, serpin family I member 1 and protein kinase cyclic adenosine monophosphate (cAMP)-dependent type I regulatory subunit beta) dementia-associated genes. Our results support the use of an extended next-generation sequencing panels as a quick, accurate, and cost-effective method for diagnosis in clinical practice. This approach could have a significant impact on the proportion of tested patients, especially among those with an early disease onset.

A new potential biomarker for dementia with Lewy bodies: Skin nerve α-synuclein deposits.

OBJECTIVE: To investigate whether (1) phosphorylated α-synuclein (p-syn) deposits in skin nerves could be useful in differentiating dementia with Lewy bodies (DLB) from different forms of dementia and (2) small fiber neuropathy (SFN) is associated with DLB. METHODS: We studied 18 well-characterized patients with DLB (11 with autonomic dysfunction), 23 patients with nonsynucleinopathy dementia (NSD; 13 with young-onset Alzheimer disease dementia, 6 frontotemporal dementia, and 4 vascular dementia), and 25 healthy controls. All participants underwent skin biopsies from proximal (i.e., cervical) and distal (i.e., thigh and distal leg) sites to study small nerve fibers and deposits of p-syn, considered the pathologic form of α-synuclein. RESULTS: No p-syn was detected in any skin sample in patients with NSD and controls but was found in all patients with DLB. SFN was found in patients with DLB and the autonomic denervation of skin was more severe in patients with autonomic dysfunctions. CONCLUSIONS: (1) In autonomic skin nerves, p-syn is a sensitive biomarker for DLB diagnosis, helping to differentiate DLB from other forms of dementia, although this needs to be confirmed in a larger, more representative sample; and (2) skin autonomic neuropathy is part of the DLB pathology and may contribute to autonomic symptoms. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that p-syn in skin nerve fibers on skin biopsy accurately distinguishes DLB from other forms of dementia.

C9ORF72 hexanucleotide repeat number in frontotemporal lobar degeneration: a genotype-phenotype correlation study.

Expansion of a hexanucleotide repeat in the C9ORF72 gene has been identified as the most common pathogenic mutation in families with autosomal dominant frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis. Herein we investigated frequency and penetrance of the C9ORF72 hexanucleotide repeat pathological expansion in a large cohort of familial and sporadic FTLD and related disorders (FTLD and related disorders, n = 388; Controls, n = 201). Moreover, we weighed the impact of C9ORF72 genotype on clinical phenotype taking into account the hexanucleotide repeat units number as a possible disease modifier. In our cohort, the C9ORF72 pathological expansion: (i) showed a prevalence of 7.5%; (ii) showed a full penetrance by the age of 80; (iii) was rarely found in sporadic patients; (iv) was solely associated with FTLD; (v) was mainly associated with bvFTD clinical subtype; and (vi) was associated with earlier age of onset in the youngest generation compared with the previous generation within a pedigree. Interestingly, intermediate C9ORF72 expansion had a risk effect in familial/sporadic FTLD. Eventually, the C9ORF72 repeat units number influenced the disease phenotype in terms of age of onset and associated clinical subtype. Genome-wide studies in well characterized clinical cohorts will be essential in order to decipher pathways of disease expression in C9ORF72-associated neurodegeneration.

A novel PSENEN mutation in a patient with complaints of memory loss and a family history of dementia.

Presenilin enhancer-2 (PSENEN) is a fundamental component of the gamma-secretase protein complex involved in beta-amyloid precursor protein (beta APP) processing, a key event in Alzheimer's disease (AD) etiopathogenesis. In a mild cognitive impairment (MCI)-diagnosed woman, belonging to a family with a positive history for AD, we found that a novel PSENEN mutation (S73F) was the only genetic alteration of relevance. The mutation was absent in 253 age-matched controls. In an attempt to learn the biochemical effects of this mutation, we cultured skin primary fibroblasts from the patient and her daughter, and we assessed A beta(1-40) and Abeta(1-42) production. We did not find any relevant differences in comparison to age-matched, normal subjects. Although our data do not definitively support a pathogenetic role for this mutation, it does not appear to be a common polymorphism. Further follow-up is warranted in this family.