RESUMO
Autoantibodies directed against the GluA3 subunit (anti-GluA3 hIgGs) of AMPA receptors have been identified in 20%-25% of patients with frontotemporal lobar degeneration (FTLD). Data from patients and in vitro/ex vivo pre-clinical studies indicate that anti-GluA3 hIgGs negatively affect glutamatergic neurotransmission. However, whether and how the chronic presence of anti-GluA3 hIgGs triggers synaptic dysfunctions and the appearance of FTLD-related neuropathological and behavioural signature has not been clarified yet. To address this question, we developed and characterized a pre-clinical mouse model of passive immunization with anti-GluA3 hIgGs purified from patients. In parallel, we clinically compared FTLD patients who were positive for anti-GluA3 hIgGs to negative ones. Clinical data showed that the presence of anti-GluA3 hIgGs defined a subgroup of patients with distinct clinical features. In the preclinical model, anti-GluA3 hIgGs administration led to accumulation of phospho-tau in the postsynaptic fraction and dendritic spine loss in the prefrontal cortex. Remarkably, the preclinical model exhibited behavioural disturbances that mostly reflected the deficits proper of patients positive for anti-GluA3 hIgGs. Of note, anti-GluA3 hIgGs-mediated alterations were rescued in the animal model by enhancing glutamatergic neurotransmission with a positive allosteric modulator of AMPA receptors. Overall, our study clarified the contribution of anti-GluA3 autoantibodies to central nervous system symptoms and pathology and identified a specific subgroup of FTLD patients. Our findings will be instrumental in the development of a therapeutic personalised medicine strategy for patients positive for anti-GluA3 hIgGs.
Assuntos
Autoanticorpos , Degeneração Lobar Frontotemporal , Animais , Humanos , Camundongos , Autoanticorpos/metabolismo , Demência Frontotemporal , Degeneração Lobar Frontotemporal/metabolismo , Degeneração Lobar Frontotemporal/patologia , Receptores de AMPA , Transmissão Sináptica , Proteínas tau/metabolismoRESUMO
BACKGROUND: Frontotemporal lobar degeneration (FTLD) and primary psychiatric disorders (PPD) are characterised by overlapping clinical features but different aetiologies. Here, we assessed for the first time the potential of blood glial fibrillar acidic protein (GFAP), marker of astrogliosis, as a discriminative and prognostic tool in FTLD and PPD. METHODS: The levels of GFAP in serum (sGFAP) of patients with FTLD (N=107) and PPD (N=44) and GFAP in whole blood samples (bGFAP) from FTLD (N=10), PPD (N=10) and healthy controls (N=18) were measured. We evaluated whether the sGFAP levels associate with C9orf72 repeat expansion, survival of FTLD and PPD patients, and brain atrophy assessed cross-sectionally and longitudinally by structural T1W MRI. We also examined the correlation between sGFAP and bGFAP levels in a subset of patients. RESULTS: sGFAP and bGFAP levels were elevated in the FTLD group compared with the PPD or control groups. Receiver operating characteristic analysis indicated an excellent diagnostic performance between FTLD and PPD (the area under the curve (AUC)=0.820, 95% CI 0.745 to 0.896). sGFAP and bGFAP levels showed a strong correlation and elevated sGFAP levels significantly associated with atrophy rate in the temporal cortex and predicted shorter survival time in patients with FTLD. No association with C9orf72 repeat expansion was detected. CONCLUSIONS: sGFAP enabled differentiation of patients with FTLD and PPD and associated with shorter survival and more severe brain atrophy rate in patients with FTLD. These results suggest that blood-based GFAP represents a minimally invasive and useful biomarker in the differential diagnostics between patients with FTLD and PPD and in evaluating disease progression and astrogliosis in FTLD.
Assuntos
Encéfalo/diagnóstico por imagem , Demência Frontotemporal/diagnóstico , Proteína Glial Fibrilar Ácida/sangue , Idoso , Atrofia/sangue , Atrofia/diagnóstico por imagem , Biomarcadores/sangue , Progressão da Doença , Feminino , Demência Frontotemporal/sangue , Demência Frontotemporal/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Prognóstico , Sensibilidade e Especificidade , Taxa de SobrevidaRESUMO
INTRODUCTION: Behavioral variant frontotemporal dementia (bvFTD) is the most common clinical subtype of frontotemporal lobar degeneration. bvFTD is often characterized by changes in behavior and personality, frequently leading to psychiatric misdiagnoses. On the other hand, substantial clinical overlap with other neurodegenerative diseases, such as Alzheimer disease (AD), further complicates the diagnostics. OBJECTIVE: Our aim was to identify the main differences in early symptoms of bvFTD and AD in the prodromal stages of the diseases. In addition, patients with bvFTD were analyzed separately according to whether they carry the C9orf72repeat expansion or not. METHODS: Patient records of bvFTD (n = 75) and AD (n = 83) patients were analyzed retrospectively for memory and neuropsychiatric symptoms, sleeping disorders, and somatic complaints before the setting of the accurate diagnosis. RESULTS: A total of 84% of bvFTD patients (n = 63) and 98.8% of AD patients (n = 82) reported subjective memory disturbances in the prodromal phases of the disease. bvFTD patients presented significantly more often with sleeping disorders, headache, inexplicable collapses, transient loss of consciousness, somatization, delusions, and hallucinations, suicidality, changes in oral behaviors, and urinary problems. In addition, poor financial judgement was frequently detected in patients with prodromal bvFTD. Aberrant sensations in the nose and throat without any physical explanation, regarded as somatizations, emerged only in bvFTD patients with the C9orf72 repeat expansion. CONCLUSIONS: Subjective reporting of impaired episodic memory is a poor indicator in differentiating bvFTD from AD. Sleeping disturbances, delusions, hallucinations, and unexplained somatic complaints in a patient with cognitive disturbances should prompt the clinicians to consider bvFTD as a possible diagnostic option behind these symptoms. The spectrum of symptoms in the prodromal stages of bvFTD may be more diverse than the latest criteria suggest.
Assuntos
Doença de Alzheimer , Sintomas Comportamentais , Demência Frontotemporal , Degeneração Lobar Frontotemporal , Idoso , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Sintomas Comportamentais/diagnóstico , Sintomas Comportamentais/etiologia , Proteína C9orf72/análise , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/etiologia , Diagnóstico Diferencial , Erros de Diagnóstico/prevenção & controle , Diagnóstico Precoce , Feminino , Demência Frontotemporal/diagnóstico , Demência Frontotemporal/psicologia , Degeneração Lobar Frontotemporal/metabolismo , Degeneração Lobar Frontotemporal/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Sintomas Prodrômicos , Estudos RetrospectivosRESUMO
OBJECTIVES: Current epidemiologic data of early-onset dementia (EOD), characterized by the onset of the disease before the age of 65, are notably scarce. METHODS: We evaluated the incidence (from January 2010 to December 2021) and prevalence (on December 31, 2021) of EOD and its subtypes in 2 defined areas in Finland. All visits at the dementia outpatient clinics were manually retrospectively reviewed and reassessed (N = 12,490). RESULTS: In the population aged ≤65 years, crude incidence of EOD was 12.3/100,000 persons at risk/year based on 794 new cases from January 1, 2010, to December 31, 2021. Incidence rates for EOD were 20.5 and 33.7 per 100,000 person years in the age group of 30-64 and 45-64 years, respectively. The prevalence of EOD was 110.4 in the age group of 30-64 years and 190.3 in the age group 45-64. Alzheimer disease (AD) (48.2%) and behavioral variant frontotemporal dementia (12.7%) were the most frequent subtypes. The incidence of AD increased during the follow-up, whereas incidence of other forms of EOD remained stable. DISCUSSION: We found higher incidence rates of EOD than previously reported. Unlike other forms of EOD, the incidence of early-onset AD seems to be increasing.
Assuntos
Idade de Início , Demência , Humanos , Finlândia/epidemiologia , Pessoa de Meia-Idade , Incidência , Feminino , Masculino , Prevalência , Adulto , Demência/epidemiologia , Estudos Retrospectivos , Doença de Alzheimer/epidemiologiaRESUMO
BACKGROUND: Due to the significant presence of neuropsychiatric symptoms in patients with frontotemporal dementia (FTD) spectrum disorders, psychiatric misdiagnoses, diagnostic delay, and use of psychiatric treatments are common prior to the FTD diagnosis. Furthermore, treatment of diagnosed FTD patients mainly relies on off-label psychopharmacological approaches. Currently, limited real-world data are available regarding the actual use of psychopharmacological medications in FTD. OBJECTIVE: To evaluate psychopharmacological medication use at the time of FTD diagnosis. METHODS: Psychopharmacological medication use was evaluated in a Finnish FTD cohort containing 222 FTD patients, including the major clinical disease phenotypes (behavioral, language, and motor variants) and genetic patients carrying the C9orf72 repeat expansion. A cohort of 214 Alzheimer's disease (AD) patients was used as a neurodegenerative disease reference group. RESULTS: Active use of psychopharmacological medications at the time of diagnosis was significantly more common in FTD compared to AD, especially in the case of antidepressants (26.1% versus 15.0%, ORâ=â2.01, pâ=â0.008), antipsychotics (23.9% versus 9.3%, ORâ=â3.15, pâ<â0.001), and mood-stabilizers (6.3% versus 1.9%, ORâ=â2.93, pâ=â0.085; not statistically significant), whereas the use of cholinesterase inhibitors or memantine was nearly nonexistent in FTD patients. Female gender and behavioral variant of FTD phenotype alongside with depressive and psychotic symptoms were the most prominent factors associating with the use of these medications among the FTD spectrum patients. CONCLUSION: Use of off-label psychopharmacological medication and polypharmacy is substantially common at the time of FTD diagnosis. This likely reflects the challenges in using symptom-driven treatment approaches, especially prior to the eventual diagnosis.
Assuntos
Doença de Alzheimer , Demência Frontotemporal , Doenças Neurodegenerativas , Humanos , Feminino , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Demência Frontotemporal/diagnóstico , Demência Frontotemporal/tratamento farmacológico , Demência Frontotemporal/genética , Doenças Neurodegenerativas/tratamento farmacológico , Diagnóstico Tardio , Memantina/uso terapêuticoRESUMO
BACKGROUND: Currently, there are few studies considering possible modifiable risk factors of frontotemporal dementia (FTD). OBJECTIVE: In this retrospective case-control study, we evaluated whether a history of traumatic brain injury (TBI) associates with a diagnosis of FTD or modulates the clinical phenotype or onset age in FTD patients. METHODS: We compared the prevalence of prior TBI between individuals with FTD (Nâ=â218) and age and sex-matched AD patients (Nâ=â214) or healthy controls (HC; Nâ=â100). Based on the patient records, an individual was categorized to the TBI+ group if they were reported to have suffered from TBI during lifetime. The possible associations of TBI with age of onset and disease duration were also evaluated in the whole FTD patient group or separately in the sporadic and genetic FTD groups. RESULTS: The prevalence of previous TBI was the highest in the FTD group (19.3%) when compared to the AD group (13.1%, pâ=â0.050) or HC group (12%, pâ=â0.108, not significant). Preceding TBI was more often associated with the sporadic FTD cases than the C9orf72 repeat expansion-carrying FTD cases (pâ=â0.003). Furthermore, comparison of the TBI+ and TBI- FTD groups indicated that previous TBI was associated with an earlier onset age in the FTD patients (Bâ=â3.066, pâ=â0.010). CONCLUSION: A preceding TBI associates especially with sporadic FTD and with earlier onset of symptoms. The results of this study suggest that TBI may be a triggering factor for the neurodegenerative processes in FTD. However, understanding the precise underlying mechanisms still needs further studies.
Assuntos
Lesões Encefálicas Traumáticas , Demência Frontotemporal , Humanos , Demência Frontotemporal/epidemiologia , Demência Frontotemporal/genética , Demência Frontotemporal/diagnóstico , Estudos Retrospectivos , Estudos de Casos e Controles , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/epidemiologia , Proteína C9orf72/genéticaRESUMO
Frontotemporal dementia (FTD) can manifest as diverse clinical phenotypes and is frequently caused by mutations in different genes, complicating differential diagnosis. This underlines the urgent need for valid biomarkers. Altered lysosomal and immune functions proposedly contribute to FTD pathogenesis. Cathepsins, including cathepsin S, are enzymes preferentially expressed in brain in microglia, which influence lysosomal and immune function. Here, we examined whether alterations in serum cathepsin S levels associate with specific clinical, genetic, or neuropathological FTD subgroups, but no such alterations were observed. However, further research on other lysosomal proteins may reveal new biologically relevant biomarkers in FTD.
Assuntos
Demência Frontotemporal , Humanos , Demência Frontotemporal/diagnóstico , Proteínas tau/metabolismo , Encéfalo/patologia , Mutação/genética , Biomarcadores , Catepsinas/genética , Catepsinas/metabolismo , Proteína C9orf72/genéticaRESUMO
INTRODUCTION: The biallelic repeat expansion (AAGGG)exp in RFC1 causes cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS). Recently, cognitive impairment has been reported in patients with CANVAS and a broader neurodegenerative process associated with RFC1 has been suggested. Furthermore, rare cases of multiple system atrophy, Parkinson's disease, amyotrophic lateral sclerosis or CANVAS with features of dementia with Lewy bodies have been found. OBJECTIVE: We hypothesized that the biallelic (AAGGG)exp is associated with neurodegeneration manifested as cognitive symptoms and that atypical RFC1 disease may be found among patients with cognitive disorder. METHODS: Clinical data on nine patients with biallelic (AAGGG)exp were reviewed and 564 patients with Alzheimer's disease or frontotemporal dementia (FTD) were investigated for biallelic RFC1 (AAGGG)exp. RESULTS: Five patients with biallelic (AAGGG)exp were found with a cognitive impairment and in four of them the phenotype resembled FTD. However, biallelic (AAGGG)exp was not detected among patients with Alzheimer's disease or FTD. CONCLUSION: Cognitive impairment is a feature in patients with the biallelic (AAGGG)exp, but the pathogenic expansion seems to be rare in patients with dementia. Studies on patients with diverse phenotypes would be useful to further explore the involvement of RFC1 in neuronal degeneration and to identify atypical phenotypes, which should be taken into account in clinical practice.
Assuntos
Doença de Alzheimer , Ataxia Cerebelar , Disfunção Cognitiva , Demência Frontotemporal , Humanos , Demência Frontotemporal/genética , Ataxia Cerebelar/genética , Disfunção Cognitiva/genética , CogniçãoRESUMO
Extrapyramidal (EP) symptoms are a known feature in a subpopulation of patients with behavioral variant frontotemporal dementia (bvFTD). Concomitant EP symptoms with FTD-like neuropsychiatric symptoms are also core features in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). This complicates the early diagnosis of these disorders. Our retrospective register study aimed to discover imaging (MRI and FDG-PET) biomarkers to differentiate PSP, CBD, and bvFTD patients with extrapyramidal symptoms (EP +) from bvFTD patients without EP symptoms (EP-). The records of 2751 patients were screened for the diagnoses and presence of EP symptoms. A total of 222 patients were submitted to imaging analysis and applicable imaging data were recovered from 139 patients. Neuroimaging data were analyzed using Freesurfer software. In the whole cohort, EP + patients showed lower volumes of gray matter compared to EP- patients in the putamen (p = 0.002), bilateral globus pallidum (p = 0.002, p = 0.042), ventral diencephalon (p = 0.002) and brain stem (p < 0.001). In the bvFTD subgroup, there was volumetric difference between EP + and EP- patients in the brain stem. FDG-PET scans in the bvFTD patient subgroup showed that EP + patients had comparative hypometabolism of the superior cerebellar peduncle (SCP) and the frontal lobes. We discovered that EP symptoms are linked to brainstem atrophy in bvFTD patients and the whole cohort. Also, evident hypometabolism in the SCP of bvFTD EP + patients was detected as compared to bvFTD EP- patients. This could indicate that the EP symptoms in these diseases have a more caudal origin in the brainstem than in Parkinson's disease.
Assuntos
Doenças dos Gânglios da Base , Demência Frontotemporal , Atrofia , Doenças dos Gânglios da Base/diagnóstico por imagem , Tronco Encefálico , Fluordesoxiglucose F18 , Demência Frontotemporal/complicações , Demência Frontotemporal/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Estudos RetrospectivosRESUMO
OBJECTIVE: Only a few studies have evaluated modifiable risk factors for frontotemporal dementia (FTD). Here, we evaluated several modifiable factors and their association with disease phenotype, genotype, and prognosis in a large study population including Finnish and Italian patients with FTD and control groups. METHODS: In this case-control study, we compared the presence of several cardiovascular and other lifestyle-related diseases and education between Finnish and Italian patients with familial (n = 376) and sporadic (n = 654) FTD, between different phenotypes of FTD, and between a subgroup of Finnish FTD patients (n = 221) and matched Finnish patients with Alzheimer's disease (AD) (n = 214) and cognitively healthy controls (HC) (n = 100). RESULTS: Patients with sporadic FTD were less educated (p = 0.042, B = -0.560, 95% CI -1.101 to -0.019) and had more heart diseases (p < 0.001, OR = 2.265, 95% CI 1.502-3.417) compared to patients with familial FTD. Finnish FTD patients were less educated (p = 0.032, B = 0.755, 95% CI 0.064-1.466) compared with AD patients. The Finnish FTD group showed lower prevalence of hypertension than the HC group (p = 0.003, OR = 2.162, 95% CI 1.304-3.583) and lower prevalence of hypercholesterolemia than in the HC group (p < 0.001, OR = 2.648, 95%CI 1.548-4.531) or in the AD group (p < 0.001, OR = 1.995, 95% CI 1.333-2.986). Within the FTD group, clinical phenotypes also differed regarding education and lifestyle-related factors. INTERPRETATION: Our study suggests distinct profiles of several modifiable factors in the FTD group depending on the phenotype and familial inheritance history and that especially sporadic FTD may be associated with modifiable risk factors.
Assuntos
Doença de Alzheimer , Demência Frontotemporal , Doença de Pick , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/genética , Estudos de Casos e Controles , Demência Frontotemporal/epidemiologia , Demência Frontotemporal/genética , Humanos , Fatores de RiscoRESUMO
BACKGROUND: Frontotemporal dementia (FTD) covers a spectrum of neurodegenerative disorders with various clinical and neuropathological subtypes. The two major pathological proteins accumulating in the brains of FTD patients, depending on their genetic background, are TDP-43 and tau. We aimed to evaluate whether total TDP-43 levels measured from the serum associate with the genotype or clinical phenotype of the FTD patients and whether serum TDP-43 provides prognostic or diagnostic value in the FTD spectrum disorders. METHODS: The study cohort included 254 participants with a clinical diagnosis of FTD (including all major genotypes and clinical phenotypes) and 105 cognitively healthy controls. Serum total TDP-43 levels measured with a single-molecule array (Simoa) were compared within the FTD group according to the genotype, clinical phenotype, and predicted neuropathological subtype of the patients. We also evaluated the associations between the TDP-43 levels and disease severity or survival in FTD. RESULTS: Total TDP-43 levels in the serum were significantly lower in the FTD group as compared to the healthy control group (275.3 pg/mL vs. 361.8 pg/mL, B = 0.181, 95%CI = 0.014-0.348, p = 0.034). The lowest TDP-43 levels were observed in the subgroup of FTD patients harboring predicted TDP-43 brain pathology (FTD-TDP, 241.4 pg/mL). The low levels in the FTD-TDP group were especially driven by C9orf72 repeat expansion carriers (169.2 pg/mL) and FTD patients with concomitant motoneuron disease (FTD-MND, 113.3 pg/mL), whereas GRN mutation carriers did not show decreased TDP-43 levels (328.6 pg/mL). Serum TDP-43 levels showed no correlation with disease severity nor progression in FTD. CONCLUSIONS: Our results indicate that the total levels of TDP-43 in the serum are decreased especially in FTD patients with the C9orf72 repeat expansion or FTD-MND phenotype, both subtypes strongly associated with TDP-43 type B brain pathology. Serum-based measurement of TDP-43 could represent a useful tool in indicating C9orf72 repeat expansion and FTD-MND-related TDP-43 neuropathology for future diagnostics and intervention studies.
Assuntos
Proteína C9orf72 , Demência Frontotemporal , Doença dos Neurônios Motores , Proteína C9orf72/genética , Expansão das Repetições de DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Demência Frontotemporal/patologia , Humanos , Doença dos Neurônios Motores/genética , Doença dos Neurônios Motores/metabolismo , Doença dos Neurônios Motores/patologia , Neurônios Motores/metabolismo , Neurônios Motores/patologia , FenótipoRESUMO
Primary progressive aphasia (PPA) forms the spectrum of language variants of frontotemporal lobar degeneration (FTLD), including three subtypes each consisting of distinctive speech and language features. Repeat expansion in C9orf72 gene is the most common genetic cause of FTLD. However, thus far only little is known about the effects of the C9orf72 repeat expansion on the phenotype of PPA. This retrospective study aimed at determining the differences between the PPA phenotypes of the C9orf72 expansion carriers and non-carriers. Our results demonstrated no significant differences between these groups, indicating that the C9orf72 repeat expansion does not substantially affect the phenotype of PPA.
Assuntos
Afasia Primária Progressiva/genética , Afasia Primária Progressiva/fisiopatologia , Proteína C9orf72/genética , Fenótipo , Idoso , Idoso de 80 Anos ou mais , Anomia/genética , Anomia/fisiopatologia , Afasia Primária Progressiva/classificação , Expansão das Repetições de DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Afasia Primária Progressiva não Fluente/genética , Afasia Primária Progressiva não Fluente/fisiopatologia , Estudos RetrospectivosRESUMO
OBJECTIVE: The aim of the present study was to compare the levels of serum neurofilament light chain (sNfL) in frontotemporal lobar degeneration (FTLD) patients of different clinical subtypes (bvFTD, PPA, and FTLD-MND) and with or without the C9orf72 repeat expansion, and to correlate sNfL levels to disease progression, assessed by the brain atrophy rate and survival time. METHODS: The sNfL levels were determined from 78 FTLD patients (C9orf72 repeat expansion carriers [n = 26] and non-carriers [n = 52]) with Single Molecule Array (SIMOA). The progression of brain atrophy was evaluated using repeated T1-weighted MRI scans and the survival time from medical records. RESULTS: In the total FTLD cohort, sNfL levels were significantly higher in C9orf72 repeat expansion carriers compared to non-carriers. Considering clinical phenotypes, sNfL levels were higher in the C9orf72 repeat expansion carriers than in the non-carriers in bvFTD and PPA groups. Furthermore, sNfL levels were the highest in the FTLD-MND group (median 105 pg/mL) and the lowest in the bvFTD group (median 27 pg/mL). Higher sNfL levels significantly correlated with frontal cortical atrophy rate and subcortical grey matter atrophy rate. The higher sNfL levels also associated with shorter survival time. INTERPRETATION: Our results indicate that the C9orf72 repeat expansion carriers show elevated sNFL levels compared to non-carriers and that the levels differ among different clinical phenotypes of FTLD. Higher sNfL levels correlated with a shorter survival time and cortical and subcortical atrophy rates. Thus, sNfL could prove as a potential prognostic biomarker in FTLD.
Assuntos
Proteína C9orf72/genética , Córtex Cerebral/patologia , Progressão da Doença , Degeneração Lobar Frontotemporal/sangue , Substância Cinzenta/patologia , Proteínas de Neurofilamentos/sangue , Idoso , Atrofia/patologia , Biomarcadores/sangue , Feminino , Degeneração Lobar Frontotemporal/genética , Degeneração Lobar Frontotemporal/patologia , Degeneração Lobar Frontotemporal/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Expansão das Repetições de TrinucleotídeosRESUMO
Due to the significant clinical overlap between frontotemporal lobar degeneration (FTLD) spectrum disorders and late-onset primary psychiatric disorders (PPD), diagnostic biomarkers reflecting the different underlying pathophysiologies are urgently needed. Thus far, elevated cerebrospinal fluid (CSF) levels of neurofilament light chain (NfL) have been reported in various neurological conditions. Furthermore, recent advancements in ultrasensitive analytical methods (e.g., single molecule array, Simoa) have enabled sensitive and less invasive NfL detection also from blood samples. In this study, we evaluated the potential of serum NfL (sNfL) as a diagnostic tool between FTLD and PPD. We analyzed sNfL levels with Simoa from 125 participants including patients from FTLD (n = 91) and PPD (n = 34) spectra. Our results show that sNfL levels are higher in the FTLD group compared to the PPD group as well as in separate clinical subtypes of FTLD compared to different psychiatric manifestations (i.e., mood or psychotic disorders). At single-subject level, discrimination between FTLD and PPD was possible with 80% sensitivity and 85% specificity (AUC = 0.850, 95% CI 0.776-0.923), and between behavioral variant frontotemporal dementia (bvFTD) and PPD with 79% sensitivity and 85% specificity (AUC = 0.830, 95% CI 0.732-0.908). These findings highlight the potential of sNfL as a discriminating biomarker for FTLD over PPD in patients with wide-ranging behavioral, psychiatric and cognitive symptoms.
Assuntos
Transtornos Psicóticos Afetivos/diagnóstico , Transtorno Bipolar/diagnóstico , Transtorno Depressivo/diagnóstico , Degeneração Lobar Frontotemporal/diagnóstico , Proteínas de Neurofilamentos/sangue , Transtornos Psicóticos/diagnóstico , Esquizofrenia/diagnóstico , Transtornos Psicóticos Afetivos/sangue , Idoso , Biomarcadores/sangue , Transtorno Bipolar/sangue , Transtorno Depressivo/sangue , Diagnóstico Diferencial , Feminino , Degeneração Lobar Frontotemporal/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Psicóticos/sangue , Esquizofrenia/sangue , Sensibilidade e EspecificidadeRESUMO
In this study, our aim was to evaluate potential peripheral inflammatory changes in frontotemporal lobar degeneration (FTLD) patients carrying or not the C9orf72 repeat expansion. To this end, levels of several inflammatory markers (MCP-1, RANTES, IL-10, IL-17A, IL-12p, IFN-γ, IL-1ß, IL-8, and hs-CRP) and blood cells counts in plasma and/or serum of FTLD patients (N = 98) with or without the C9orf72 repeat expansion were analyzed. In addition, we evaluated whether the analyzed peripheral inflammatory markers correlated with disease progression or distinct clinical phenotypes under the heterogenous FTLD spectrum. Elevated levels of pro-inflammatory RANTES or MCP-1 and decreased levels of anti-inflammatory IL-10 were found to associate with Parkinsonism and a more rapid disease progression, indicated by longitudinal measurements of either MMSE or ADCS-ADL decline. These findings were observed in the total cohort in general, whereas the C9orf72 repeat expansion carriers showed only slight differences in IL-10 and hemoglobin levels compared to non-carriers. Furthermore, these C9orf72 repeat expansion-associated differences were observed mostly in male subjects. The females in general showed elevated levels of several pro-inflammatory markers compared to males regardless of the C9orf72 genotype. Our study suggests that pro-inflammatory changes observed in the early symptomatic phase of FTLD are associated with distinct clinical profiles and a more rapid disease progression, and that the C9orf72 repeat expansion and gender may also affect the inflammatory profile in FTLD.
Assuntos
Proteína C9orf72/genética , Progressão da Doença , Degeneração Lobar Frontotemporal/sangue , Degeneração Lobar Frontotemporal/fisiopatologia , Inflamação/sangue , Idoso , Expansão das Repetições de DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores SexuaisRESUMO
Despite the current diagnostic criteria, early diagnostics of behavioral variant of frontotemporal dementia (bvFTD) has remained challenging. Patients with bvFTD often present with misleading psychiatric phenotype, and, on the other hand, impairment in memory functions have increasingly been reported. However, impaired episodic memory is currently considered as an exclusion criterion for bvFTD. Single biofluid-based or imaging biomarkers do not currently provide sufficient sensitivity or specificity for early bvFTD diagnosis at single-subject level, although studies have suggested improved accuracy with different biomarker combinations. In this mini review, we evaluate the core clinical features of early bvFTD and summarize the most potential imaging and fluid biomarkers for bvFTD diagnostics.
RESUMO
Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative diseases with a complex, but often overlapping, genetic and pathobiological background and thus they are considered to form a disease spectrum. Although neurons are the principal cells affected in FTLD and ALS, increasing amount of evidence has recently proposed that other central nervous system-resident cells, including microglia and astrocytes, may also play roles in neurodegeneration in these diseases. Therefore, deciphering the mechanisms underlying the disease pathogenesis in different types of brain cells is fundamental in order to understand the etiology of these disorders. The major genetic cause of FTLD and ALS is a hexanucleotide repeat expansion (HRE) in the intronic region of the C9orf72 gene. In neurons, specific pathological hallmarks, including decreased expression of the C9orf72 RNA and proteins and generation of toxic RNA and protein species, and their downstream effects have been linked to C9orf72 HRE-associated FTLD and ALS. In contrast, it is still poorly known to which extent these pathological changes are presented in other brain cells. Here, we summarize the current literature on the potential role of astrocytes and microglia in C9orf72 HRE-linked FTLD and ALS and discuss their possible phenotypic alterations and neurotoxic mechanisms that may contribute to neurodegeneration in these diseases.
RESUMO
Decreased levels of serum high-density lipoprotein (HDL) cholesterol have previously been linked to systemic inflammation and neurodegenerative diseases, such as Alzheimer's disease. Here, we aimed to analyze the lipoprotein profile and inflammatory indicators, the high-sensitivity C-reactive peptide (hs-CRP) and glycoprotein acetyls (GlycA), in sporadic and C9orf72 repeat expansion-associated frontotemporal lobar degeneration (FTLD) patients. The C9orf72 hexanucleotide repeat expansion is the most frequent genetic etiology underlying FTLD. The concentrations of different lipid measures in the sera of 67 FTLD patients (15 C9orf72 repeat expansion carriers), including GlycA, were analyzed by nuclear magnetic resonance spectroscopy. To verify the state of systemic inflammation, hs-CRP was also quantified from patient sera. We found that the total serum HDL concentration was decreased in C9orf72 repeat expansion carriers when compared to non-carriers. Moreover, decreased concentrations of HDL particles of different sizes and subclass were consistently observed. No differences were detected in the very low- and low-density lipoprotein subclasses between the C9orf72 repeat expansion carriers and non-carriers. Furthermore, hs-CRP and GlycA levels did not differ between the C9orf72 repeat expansion carriers and non-carriers. In conclusion, the HDL-related changes were linked with C9orf72 repeat expansion associated FTLD but were not seen to associate with systemic inflammation. The underlying reason for the HDL changes remains unclear.
Assuntos
Proteína C9orf72/genética , HDL-Colesterol/sangue , Expansão das Repetições de DNA/genética , Degeneração Lobar Frontotemporal/sangue , Degeneração Lobar Frontotemporal/genética , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Recent studies have suggested a role for immune dysregulation behind the etiology of frontotemporal lobar degeneration (FTLD). Here, we have investigated the prevalence of immunological diseases in FTLD (Nâ¯=â¯196) with and without the C9orf72 repeat expansion, Alzheimer's disease (AD) (Nâ¯=â¯193) and not cognitively impaired (NCI) subjects (Nâ¯=â¯92). The prevalence was 16.3% in FTLD, 13.5% in AD and 15.2% in NCI. Although differences between the groups did not reach statistical significance, the frequency of immunological diseases was the highest in FTLD without the C9orf72 expansion (22/117, 18.8%) and the lowest in FTLD with the expansion (6/56, 10.7%), suggesting that the C9orf72 expansion possibly influences immunological pathways in FTLD.
Assuntos
Proteína C9orf72/genética , Degeneração Lobar Frontotemporal/epidemiologia , Degeneração Lobar Frontotemporal/genética , Heterozigoto , Doenças do Sistema Imunitário/epidemiologia , Doenças do Sistema Imunitário/genética , Idoso , Estudos de Coortes , Feminino , Finlândia/epidemiologia , Degeneração Lobar Frontotemporal/imunologia , Humanos , Doenças do Sistema Imunitário/imunologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos RetrospectivosRESUMO
Several studies have reported reduced risk of cancer in patients with Alzheimer's disease (AD) or Parkinson's disease. The relationship between cancer and frontotemporal lobar degeneration (FTLD) has not been previously reported. Here, our aim was to evaluate the occurrence of cancer in Finnish FTLD patients with a high proportion of C9ORF72 repeat expansion carriers in comparison to age- and sex-matched group of AD patients and control subjects classified as not cognitively impaired (NCI). The prevalence of cancer was 9.7% in FTLD, 18.7% in AD, and 17.4% in NCI (FTLD versus AD pâ=â0.012, FTLD versus NCI pâ=â0.029) groups. No differences were observed between C9ORF72 repeat expansion carriers and non-carriers inside the FTLD group. To our knowledge, this is the first study showing significantly lower prevalence of cancer in FTLD patients compared to patients with AD or NCI subjects. Our data suggest an inverse association between neurodegeneration and cancer and that FTLD-specific mechanisms may underlie the especially strong inverse association observed in this study.