Exploring the potential of fully automated LUMIPULSE G plasma assays for detecting Alzheimer's disease pathology.

BACKGROUND: LUMIPULSE G-automated immunoassays represent a widely used method for the quantification of Alzheimer's disease (AD) biomarkers in the cerebrospinal fluid (CSF). Less invasive blood-based markers confer a promising tool for AD diagnosis at prodromal stages (mild cognitive impairment (MCI)). Highly sensitive assays for the quantification of amyloid-beta (Aß) and phosphorylated Tau-181 (p-Tau181) in the blood are showing promising results. In this study, we evaluated the clinical performance of the recently available fully automated LUMIPULSE plasma marker assays for detecting brain AD pathology and for predicting progression from MCI to AD dementia stage. METHODS: A retrospective exploratory cohort of 138 individuals (22 neurological controls [NC], 72 MCI, and 44 AD dementia patients) was included. Data regarding baseline CSF concentrations of Aß42, Aß40, t-Tau, and p-Tau181 was available and used to establish the presence of AD brain pathology. Baseline Aß42, Aß40, and p-Tau181 concentrations were determined in stored plasma samples using high-throughput fully automated LUMIPULSE assays. Progression from MCI to AD dementia was evaluated during follow-up (mean 6.4 ± 2.5 years). Moreover, a prospective validation cohort of 72 individuals with memory complaints underwent AD biomarker quantification, closely mirroring typical clinical practice. This cohort aimed to confirm the study's main findings. RESULTS: In the exploratory cohort, correlations between CSF and plasma were moderate for p-Tau181 (ρ = 0.61, p < 0.001) and weak for Aß42/Aß40 ratio (ρ = 0.39, p < 0.001). Plasma p-Tau181 and p-Tau181/Aß42 concentrations were significantly increased while Aß42/Aß40 was significantly decreased (p < 0.001) in patients with AD dementia and prodromal AD, as well as in individuals with CSF abnormal amyloid concentrations (A +). Plasma p-Tau181 showed a robust performance in differentiating patients clinically diagnosed as AD (AUC = 0.89; 95% CI 0.83-0.94); A + vs. A - (AUC = 0.84, 95% CI 0.77-0.91) and also in predicting conversion to AD dementia in MCI patients (AUC = 0.89, 95% CI 0.81-0.96). When tested in the validation cohort, plasma p-Tau181 displayed 83.3% of the overall percentage of agreement according to amyloid status. CONCLUSIONS: Our results show that the measurement of p-Tau181 in plasma has great potential as a non-invasive prognostic screening tool for implementation in a clinical setting.

Serum Neurofilament Light Chain in the Diagnostic Evaluation of Patients with Cognitive Symptoms in the Neurological Consultation of a Tertiary Center.

Serum light-chain neurofilaments (sNfL) have been investigated as a potential minimally invasive biomarker that could help in the diagnosis of patients with cognitive symptoms. We assessed the correlation between sNfL and cerebrospinal fluid (CSF) biomarkers (sNfL versus CSF NfL, ρ= 0.70, p < 0.001), the performance of sNfL in distinguishing controls from patients (controls versus frontotemporal dementia, area under curve 0.86), and sNfL differences in mild cognitive impairment according to amyloid-ß (Aß) deposition (Aß versus non-Aß, p = 0.017). Our results support the role of this biomarker in the screening and risk stratification of patients followed in a neurological consultation of a tertiary center.

Blood biomarkers in mild cognitive impairment patients: Relationship between analytes and progression to Alzheimer disease dementia.

BACKGROUND AND PURPOSE: Blood-based biomarkers are promising tools for the diagnosis of Alzheimer disease (AD) at prodromal stages (mild cognitive impairment [MCI]) and are hoped to be implemented as screening tools for patients with cognitive complaints. In this work, we evaluated the potential of peripheral neurological biomarkers to predict progression to AD dementia and the relation between blood and cerebrospinal fluid (CSF) AD markers in MCI patients referred from a general neurological department. METHODS: A group of 106 MCI patients followed at the Neurology Department of Coimbra University Hospital was included. Data regarding baseline neuropsychological evaluation, CSF levels of amyloid ß 42 (Aß42), Aß40, total tau (t-Tau), and phosphorylated tau 181 (p-Tau181) were available for all the patients. Aß42, Aß40, t-Tau, p-Tau181, glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) levels were determined in baseline stored serum and plasma samples by commercial SiMoA (Single Molecule Array) assays. Progression from MCI to AD dementia was assessed at follow-up (mean = 5.8 ± 3.4 years). RESULTS: At baseline, blood markers NfL, GFAP, and p-Tau181 were significantly increased in patients who progressed to AD at follow-up (p < 0.001). In contrast, plasma Aß42/40 ratio and t-Tau showed no significant differences between groups. NfL, GFAP, and p-Tau181 demonstrated good diagnostic accuracy to identify progression to AD dementia (area under the curve [AUC] = 0.81, 0.80, and 0.76, respectively), which improved when combined (AUC = 0.89). GFAP and p-Tau181 were correlated with CSF Aß42. Association of p-Tau181 with NfL was mediated by GFAP, with a significant indirect association of 88% of the total effect. CONCLUSIONS: Our findings highlight the potential of combining blood-based GFAP, NfL, and p-Tau181 to be applied as a prognostic tool in MCI.

Alzheimer's Disease Diagnosis Based on the Amyloid, Tau, and Neurodegeneration Scheme (ATN) in a Real-Life Multicenter Cohort of General Neurological Centers.

BACKGROUND: The ATN scheme was proposed as an unbiased biological characterization of the Alzheimer's disease (AD) spectrum, grouping biomarkers into three categories: brain Amyloidosis-A, Tauopathy-T, Neurodegeneration-N. Although this scheme was mainly recommended for research, it is relevant for diagnosis. OBJECTIVE: To evaluate the ATN scheme performance in real-life cohorts reflecting the inflow of patients with cognitive complaints and different underlying disorders in general neurological centers. METHODS: We included patients (n = 1,128) from six centers with their core cerebrospinal fluid-AD biomarkers analyzed centrally. A was assessed through Aß42/Aß40, T through pTau-181, and N through tTau. Association between demographic features, clinical diagnosis at baseline/follow-up and ATN profiles was assessed. RESULTS: The prevalence of ATN categories was: A-T-N-: 28.3%; AD continuum (A + T-/+N-/+): 47.8%; non-AD (A- plus T or/and N+): 23.9%. ATN profiles prevalence was strongly influenced by age, showing differences according to gender, APOE genotype, and cognitive status. At baseline, 74.6% of patients classified as AD fell in the AD continuum, decreasing to 47.4% in mild cognitive impairment and 42.3% in other neurodegenerative conditions. At follow-up, 41% of patients changed diagnosis, and 92% of patients that changed to AD were classified within the AD continuum. A + was the best individual marker for predicting a final AD diagnosis, and the combinations A + T+ (irrespective of N) and A + T+N+ had the highest overall accuracy (83%). CONCLUSION: The ATN scheme is useful to guide AD diagnosis in real-life neurological centers settings. However, it shows a lack of accuracy for patients with other types of dementia. In such cases, the inclusion of other markers specific for non-AD proteinopathies could be an important aid to the differential diagnosis.

Serum neurofilament light chain as a surrogate of cognitive decline in sporadic and familial frontotemporal dementia.

BACKGROUND AND PURPOSE: Neurofilament light chain (NfL) has recently been proposed as a promising biomarker in frontotemporal dementia (FTD). We investigated the correlation of both cerebrospinal fluid (CSF) and serum NfL with detailed neuropsychological data and cognitive decline in a cohort of sporadic and familial FTD. METHODS: CSF and serum NfL, as well as conventional CSF Alzheimer's disease (AD) biomarkers (Aß42, t-Tau, p-Tau181), were determined in 63 FTD patients (30 sporadic-FTD, 20 with progranulin (GRN) mutations [FTD-GRN], 13 with chromosome 9 open reading frame 72 [C9orf72] expansions [C9orf72-FTD]), 37 AD patients, and 31 neurologic controls. Serum NfL was also quantified in 37 healthy individuals. Correlations between baseline CSF and serum NfL levels, standardized neuropsychological tests, and the rate of cognitive decline in FTD patients were assessed. RESULTS: CSF and serum NfL presented with significantly higher levels in FTD than in AD patients and both control groups. Within FTD subtypes, genetic cases, and particularly FTD-GRN, had higher CSF and serum NfL levels. Significant correlations between NfL levels and overall cognitive function, abstract reasoning (CSF and serum), executive functions, memory, and language (serum) were found. A relationship between increased baseline CSF and serum NfL and a decay in cognitive performance over time was also observed. CONCLUSIONS: Our findings highlight the potential of serum NfL as a useful surrogate end point of disease severity in upcoming targeted treatments.

Podemos falar de segurança do paciente durante uma pandemia? Uma experiência portuguesa / Can we talk about patient safety during a pandemia? A portuguese experience / ¿Podemos hablar sobre seguridad del paciente durante una pandemia? Una experiencia portuguesa

Objetivo: enumerar medidas governativas e de saúde pública implementadas em Portugal decorrentes da pandemia pelo vírus SARS-CoV-2 e descrever a atuação do Gabinete de Segurança do Paciente do Centro Hospitalar Universitário de Lisboa Central (CHULC), referência nacional na resposta à situação de emergência de saúde pública. Métodos: utilizou-se como método a análise normativa, documental, além de relato de caso por pesquisa-ação. Resultados: em Portugal, documentaram-se os primeiros casos de infeção por SARS-CoV-2 a 2 de março de 2020. Os processos assistenciais são geridos pelo Ministério da Saúde e Direção Geral da Saúde, abrangendo o Sistema Nacional de Saúde (universal) e o sector privado. O Gabinete de Segurança do Doente do CHULC, participou na redefinição dos processos, criação de vias alternativas de informação entre as várias estruturas, implementação de inovações no uso de tecnologias e vigilância clínica, gestão dos equipamentos de proteção, motivação e suporte emocional dos profissionais e na consolidação das principais metas de segurança do doente (ex. identificação do doente, medicação e cirurgia segura). A aprendizagem feita com os erros contribui para a melhoria contínua dos processos. Conclusão: em Portugal e no mundo a pandemia por COVID-19 não terminou. Compreendemos que é tempo de refletir e voltar aos princípios básicos da segurança, como a higiene das mãos, a etiqueta respiratória e o controlo ambiental. Na gestão do risco e segurança do paciente em situação de crise, é necessário, mais do que nunca, inovar e aprender com os erros.

Objective: to enumerate governmental and public health measures implemented in Portugal resulting from the SARS-CoV-2 virus pandemic and describe the work of the Patient Safety Office of the Centro Hospitalar Universitário de Lisboa Central (CHULC), a national reference in the response to the situation of public health emergency. Methods: normative, documentary analysis was used as a method, in addition to case reports by action research. Results: in Portugal, the first cases of SARS-CoV-2 infection were documented on March 2, 2020. Assistance processes are managed by the Ministry of Health and the General Directorate of Health, covering the National Health System (universal) and the private sector. The CHULC Patient Safety Office, participated in the redefinition of processes, creation of alternative information routes between the various structures, implementation of innovations in the use of technologies and clinical surveillance, management of protective equipment, motivation and emotional support from professionals and consolidating the main patient safety goals (eg patient identification, medication and safe surgery). Learning from mistakes contributes to the continuous improvement of processes. Conclusion: In Portugal and in the world, the COVID-19 pandemic has not ended. We understand that it is time to reflect and return to the basic principles of safety, such as hand hygiene, respiratory etiquette and environmental control. In the management of risk and safety of patients in crisis situations, it is necessary, more than ever, to innovate and learn from mistakes.

Objetivo: enumerar las medidas gubernamentales y de salud pública implementadas en Portugal como resultado de la pandemia del virus SARS-CoV-2 y describir el trabajo de la Oficina de Seguridad del Paciente del Centro Hospitalar Universitário de Lisboa Central (CHULC), una referencia nacional en la respuesta a la situación de emergencia de salud pública. Métodos: se utilizó como método el análisis documental, normativo, además de los reportes de casos por investigación-acción. Resultados: en Portugal se documentaron los primeros casos de infección por SARS-CoV-2 el 2 de marzo de 2020. Los procesos de atención son gestionados por el Ministerio de Salud y la Dirección General de Salud, abarcando el Sistema Nacional de Salud (universal) y el privado. sector. La Oficina de Seguridad del Paciente del CHULC, participó en la redefinición de procesos, creación de rutas alternativas de información entre las distintas estructuras, implementación de innovaciones en el uso de tecnologías y vigilancia clínica, manejo de equipos de protección, motivación y apoyo emocional de los profesionales y consolidando las principales objetivos de seguridad del paciente (por ejemplo, identificación del paciente, medicación y cirugía segura). Aprender de los errores contribuye a la mejora continua de los procesos. Conclusión: En Portugal y en el mundo, la pandemia de COVID-19 no ha terminado. Entendemos que es hora de reflexionar y volver a los principios básicos de seguridad, como la higiene de manos, la etiqueta respiratoria y el control ambiental. En la gestión del riesgo y la seguridad de los pacientes en situaciones de crisis, es necesario, más que nunca, innovar y aprender de los errores.

C-reactive protein as a predictor of mild cognitive impairment conversion into Alzheimer's disease dementia.

BACKGROUND AND AIMS: Increasing evidence suggests that inflammation plays an important role in brain aging and neurodegeneration. Pathological studies demonstrate the presence of C-reactive protein (CRP) in the senile plaques and neurofibrillary tangles in Alzheimer's disease (AD) brain tissue suggesting that CRP may play a role in its neuropathological processes. Some findings suggest that midlife elevations of serum CRP are a risk factor for AD. However, others found lower CRP levels in mild or moderate AD than in controls, suggesting that CRP levels could be different in different stages of disease. We aimed to assess the role of CRP as a predictor of Mild cognitive impairment (MCI) conversion into AD dementia. METHODS: We retrospectively reviewed the cohort of MCI patients followed at the Dementia Clinic, Neurology Department of University Hospital of Coimbra. We collected demographical, neuropsychological, genetic and laboratorial variables (including serum CRP measurements at the time of baseline laboratory tests). A Cox regression model was performed adjusted for the collected variables preconsidered to be predictors of dementia and the variable being studied (CRP) to assess for independent predictors of conversion. RESULTS: We included 130 patients, 58.5% female, with a mean age of onset of 65.5 ± 9.1 years and age at first assessment of 69.3 ± 8.5 years. The mean CRP was 0.33 ± 0.58 mg/dl. At follow-up (mean, 36.9 ± 27.0 months) 42.3% of MCI patients converted to dementia. Lower CSF Aß42 (HR = 0.999, 95%CI = [0.997, 1.000], p = 0.015), lower MMSE score (HR = 0.864, 95%CI = [0.510, 1.595], p = 0.008) and lower CRP quartile (HR = 0.597, 95%CI = [0.435, 0.819], p = 0.001) were independent predictors of conversion. CONCLUSION: CRP may add information of risk of conversion in MCI patients. Patients with lower CRP levels appear to have a more rapid conversion to AD dementia.

Lower CSF Amyloid-Beta1-42 Predicts a Higher Mortality Rate in Frontotemporal Dementia.

Frontotemporal lobar degeneration, the neuropathological substrate of frontotemporal dementia (FTD), is characterized by the deposition of protein aggregates, including tau. Evidence has shown concomitant amyloid pathology in some of these patients, which seems to contribute to a more aggressive disease. Our aim was to evaluate cerebrospinal fluid (CSF) amyloid-beta as a predictor of the mortality of FTD patients. We included 99 patients diagnosed with FTD-both behavioral and language variants-with no associated motor neuron disease, from whom a CSF sample was collected. These patients were followed prospectively in our center, and demographic and clinical data were obtained. The survival analysis was carried through a Cox regression model. Patients who died during follow up had a significantly lower CSF amyloid-beta1-42 than those who did not. The survival analysis demonstrated that an increased death rate was associated with a lower CSF amyloid-beta1-42 (HR = 0.999, 95% CI = [0.997, 1.000], p = 0.049). Neither demographic nor clinical variables, nor CSF total tau or p-tau were significantly associated with this endpoint. These results suggest that amyloid deposition in FTD patients may be associated with a higher mortality.

Clinical validation of the Lumipulse G cerebrospinal fluid assays for routine diagnosis of Alzheimer's disease.

BACKGROUND: Ongoing efforts within the Alzheimer's disease (AD) field have focused on improving the intra- and inter-laboratory variability for cerebrospinal fluid (CSF) biomarkers. Fully automated assays offer the possibility to eliminate sample manipulation steps and are expected to contribute to this improvement. Recently, fully automated chemiluminescence enzyme immunoassays for the quantification of all four AD biomarkers in CSF became available. The aims of this study were to (i) evaluate the analytical performance of the Lumipulse G ß-Amyloid 1-42 (restandardized to Certified Reference Materials), ß-Amyloid 1-40, total Tau, and pTau 181 assays on the fully automated LUMIPULSE G600II; (ii) compare CSF biomarker results of the Lumipulse G assays with the established manual ELISA assays (INNOTEST®) from the same company (Fujirebio); and (iii) establish cut-off values and the clinical performance of the Lumipulse G assays for AD diagnosis. METHODS: Intra- and inter-assay variation was assessed in CSF samples with low, medium, and high concentrations of each parameter. Method comparison and clinical evaluation were performed on 40 neurological controls (NC) and 80 patients with a diagnosis of probable AD supported by a follow-up ≥ 3 years and/or positive amyloid PET imaging. A small validation cohort of 10 NC and 20 AD patients was also included to validate the cut-off values obtained on the training cohort. RESULTS: The maximal observed intra-assay and inter-assay coefficients of variation (CVs) were 3.25% and 5.50%, respectively. Method comparisons revealed correlation coefficients ranging from 0.89 (for Aß40) to 0.98 (for t-Tau), with those for Aß42 (0.93) and p-Tau (0.94) in-between. ROC curve analysis showed area under the curve values consistently above 0.85 for individual biomarkers other than Aß40, and with the Aß42/40, Aß42/t-Tau, and Aß42/p-Tau ratios outperforming Aß42. Validation of the cut-off values in the independent cohort showed a sensitivity ranging from 75 to 95% and a specificity of 100%. The overall percentage of agreement between Lumipulse and INNOTEST was very high (> 87.5%). CONCLUSIONS: The Lumipulse G assays show a very good analytical performance that makes them well-suited for CSF clinical routine measurements. The good clinical concordance between the Lumipulse G and INNOTEST assays facilitates the implementation of the new method in routine practice.

Increased CSF tau is associated with a higher risk of seizures in patients with Alzheimer's disease.

INTRODUCTION: Neurofibrillary tangles and tau protein, the neuropathological hallmarks of Alzheimer's disease (AD), have been identified in patients with epilepsy. Tau protein was also associated with the modulation of neuronal excitability in animal models of AD. MATERIALS AND METHODS: We evaluated in 292 patients with AD the association between the risk of seizure development and AD cerebrospinal fluid (CSF) biomarkers, demographic characteristics, baseline Mini-Mental State Examination (MMSE) score, comorbidities, and apolipoprotein E status. RESULTS: The development of seizures was associated with younger age at dementia's onset, lower baseline MMSE, and higher CSF total tau protein levels, but only MMSE (hazard ratio [HR] = 0.935; 95% confidence interval [CI] = [0.903, 0.968]; p < 0.001) and CSF tau (HR = 1.001; 95%CI = [1.001, 1.002]; p = 0.001) were independent predictors on multivariate analysis. DISCUSSION: While CSF tau and lower baseline MMSE association with seizure development could in part be explained by a greater degree of cortical damage, the role of tau in the modulation of neuronal excitability may also play a role and should be further investigated.

Erlangen Score as a tool to predict progression from mild cognitive impairment to dementia in Alzheimer's disease.

BACKGROUND: The previously described and validated Erlangen Score (ES) algorithm enables interpretation of the cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD), ordering them on an ordinal scale: from neurochemically normal (ES = 0) through improbable AD (ES = 1), possible AD (ES = 2 or 3), to probable AD (ES = 4). Here we assess the accuracy of the ES in predicting hazards of progression from the mild cognitive impairment (MCI) stage of AD to the dementia stage of the disease (Alzheimer's disease dementia (ADD)) in a novel, single-center cohort. METHODS: Baseline CSF biomarkers (amyloid beta (Aß) 1-42, Aß42/40, Tau, and pTau181), interpreted according to the ES, were used to estimate time to progression from the MCI stage of AD to ADD, conditional on age, gender, APOE ε4 genotype, and Mini Mental State Examination score in 144 MCI subjects, using the Extended Cox Model; the subjects were followed-up until they developed dementia or until they had been cognitively stable for at least 2 years. In addition, ES distributions were studied in 168 ADD cases and 66 neurologic controls. Further, we stratified MCI patients into those who progressed to ADD faster (within 3 years, n = 47) and those who progressed slower (n = 74). RESULTS: The distributions of the ES categories across the four diagnostic groups (Controls, MCI-Stable, MCI-AD, and ADD) were highly significantly different (Kruskal-Wallis χ2(df = 3) = 151.4, p < 0.001), with significant contrasts between each pair (p < 0.005), except between the ADD and the MCI-AD groups (p = 1.0). MCI patients with ES = 2 or 3 had 6-8 times higher hazards to progress to ADD compared to patients with ES = 0 or 1 in the first 3 follow-up years, and then their hazards decreased to those of the group with ES = 0 or 1. Patients with ES = 4 had hazards 8-12 times higher compared to the ES = 0 or 1 group. Faster progressors with ES = 2 or 3 had, in comparison to slower progressors, significantly lower Aß1-42, Aß1-40, and Aß42/40, but comparable Tau and pTau181. A highly significant difference of the ES distributions between these two groups was observed (p < 0.001). CONCLUSIONS: Our current results reconfirm and extend the conclusions of the previously published report that the Erlangen Score is a useful tool facilitating interpretation of a complex pattern of the CSF AD biomarkers.

Addition of the Aß42/40 ratio to the cerebrospinal fluid biomarker profile increases the predictive value for underlying Alzheimer's disease dementia in mild cognitive impairment.

BACKGROUND: Cerebrospinal fluid (CSF) biomarkers have been used to increase the evidence of underlying Alzheimer's disease (AD) pathology in mild cognitive impairment (MCI). However, CSF biomarker-based classification often results in conflicting profiles with controversial prognostic value. Normalization of the CSF Aß42 concentration to the level of total amyloid beta (Aß), using the Aß42/40 ratio, has been shown to improve the distinction between AD and non-AD dementia. Therefore, we evaluated whether the Aß42/40 ratio would improve MCI categorization and more accurately predict progression to AD. METHODS: Our baseline population consisted of 197 MCI patients, of which 144 had a follow-up ≥ 2 years, and comprised the longitudinal study group. To establish our own CSF Aß42/40 ratio reference value, a group of 168 AD-dementia patients and 66 neurological controls was also included. CSF biomarker-based classification was operationalized according to the framework of the National Institute of Aging-Alzheimer Association criteria for MCI. RESULTS: When using the core CSF biomarkers (Aß42, total Tau and phosphorylated Tau), 30% of the patients fell into the high-AD-likelihood (HL) group (both amyloid and neurodegeneration markers positive), 30% into the low-AD-likelihood group (all biomarkers negative), 28% into the suspected non-Alzheimer pathophysiology (SNAP) group (only neurodegeneration markers positive) and 12% into the isolated amyloid pathology group (only amyloid-positive). Replacing Aß42 by the Aß42/40 ratio resulted in a significant increase in the percentage of patients with amyloidosis (42-59%) and in the proportion of interpretable biological profiles (61-75%), due to a reduction by half in the number of SNAP cases and an increase in the proportion of the HL subgroup. Survival analysis showed that risk of progression to AD was highest in the HL group, and increased when the Aß42/40 ratio, instead of Aß42, combined with total Tau and phosphorylated Tau was used for biomarker-based categorization. CONCLUSIONS: Our results confirm the usefulness of the CSF Aß42/40 ratio in the interpretation of CSF biomarker profiles in MCI patients, by increasing the proportion of conclusive profiles and enhancing their predictive value for underlying AD.

Multiple sclerosis: Association of gelatinase B/matrix metalloproteinase-9 with risk and clinical course the disease.

BACKGROUND: Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation and axonal degeneration of the central nervous system and a leading cause of disability in young adults. The matrix metalloproteinases in general and specially gelatinase B/metalloproteinase-9 (MMP-9) plays a role in the pathogenesis of multiple sclerosis. OBJECTIVE: To investigate the presence of the MMP-9 -1562C/T polymorphism in a Portuguese population of MS patients and assess its impact in susceptibility and course of the disease. The relation of MMP-9 serum levels with the polymorphism and with clinical and therapeutic factors will also be assessed. METHODS: Our study included 355 Caucasian individuals distributed as MS patients (n=169) and controls (n=186). Samples were genotyped for -1562C/T polymorphism by PCR-RFLP analysis. MMP-9 concentration in serum was analyzed using a commercially available enzyme-linked immunosorbent assay. RESULTS: A significant increase in T-allele frequency was found in female MS patients, but not in the total patient population. No association between the presence of the polymorphism and disease progression was found. MMP-9 serum concentrations were increased in patients, and although not influenced by the -1562C/T polymorphism, were modified by INF-beta therapy. CONCLUSION: Although we did not find an association of this polymorphism with disease susceptibility or prognosis, MMP-9 appears to be a good therapeutic response marker for multiple sclerosis.

Prognosis of Early-Onset vs. Late-Onset Mild Cognitive Impairment: Comparison of Conversion Rates and Its Predictors.

BACKGROUND: Despite having the same histopathological characteristics, early-onset and late-onset Alzheimer's disease (AD) patients show some distinct clinical and neuropsychological profiles. Early Onset Mild Cognitive Impairment (EOMCI) is a less characterized group. The aim of this study is to characterize MCI probably due to AD in terms of the clinical, genetic, Cerebrospinal fluid (CSF) biomarkers profile and conversion rate of EOMCI, compared to the late-onset form (LOMCI). METHODS: 159 MCI patients were divided in two groups: 52 EOMCI (onset < 65 years) and 107 LOMCI (onset ≥ 65 years). We investigated differences in neuropsychological scores, clinical variables, ApoE genotype, CSF biomarkers (Aß42, t-Tau and p-Tau) in both groups. Conversion was ascertained during follow-up. RESULTS: EOMCI showed a longer duration of symptoms prior to the first evaluation (EOMCI = 4.57 vs. LOMCI = 3.31, p = 0.008) and scored higher on the subjective memory complaints scale (9.91 vs. 7.85, p = 0.008), but performed better in brief cognitive tests (27.81 vs. 26.51, p < 0.001 in Mini-Mental State Examination; 19.84 vs. 18.67, p = 0.005 in Montreal Cognitive Assessment) than LOMCI. ApoE genotype distribution and CSF biomarker profile were similar in both groups, as was the conversion risk. Lower Aß42 (Hazard ratio (HR): 0.998, 95% Confidence Interval (CI) = [0.996⁻1.000], p = 0.042), higher t-Tau levels (HR: 1.003, 95%CI = [1.000⁻1.005], p = 0.039) and higher scores in the Alzheimer Disease Assessment Scale-Cognitive (HR: 1.186, 95%CI = [1.083⁻1.299], p = 0.002) increased the risk of conversion. DISCUSSION: Despite differences in memory performance and memory complaints, EOMCI and LOMCI seem to represent indistinct biological groups that do not have a higher risk of conversion to AD or differ in risk factors for conversion.

Cerebrospinal fluid Aß40 is similarly reduced in patients with Frontotemporal Lobar Degeneration and Alzheimer's Disease.

Cerebrospinal fluid (CSF) biomarkers have been increasingly studied for dementia diagnosis, however the accuracy to distinguish between different forms of dementia is still unsatisfactory. In this study, the added value of another CSF Aß-peptide (Aß40), along with the core CSF markers t-Tau, p-Tau, and Aß42, in the discrimination between two large dementia groups of Frontotemporal Lobar Degeneration (FTLD; n=107), Alzheimer's Disease (AD; n=107) and non-demented subjects (n=33) was evaluated. In FTLD, t-Tau and p-Tau were significantly increased in relation to controls, but lower than in AD, while Aß42 was similar in FTLD and controls, but higher than in AD. Equally reduced Aß40 levels were seen in both dementia groups, and therefore the combination of Aß40 with core CSF biomarkers optimally discriminated FTLD and AD patients from controls. Aß42 and t-Tau were selected as the best biomarker subset to differentiate FTLD from AD, with no added value of Aß40 to the model. Diagnostic accuracy between FTLD and AD was still sub-optimal, with a significant percentage (23%) of FTLD patients, in particularly women, carrying an ApoE-ε4 allele, showing a CSF-AD biomarkers profile. Although CSF Aß40 does not appear to have an additional value in the distinction between FTLD and AD, it increases the discrimination between subjects with dementia from controls. A CSF-AD biomarker profile can be seen in patients with a clinical phenotype of FTLD, reinforcing the need for autopsy confirmation.

Chasing the Effects of Pre-Analytical Confounders - A Multicenter Study on CSF-AD Biomarkers.

INTRODUCTION: Core cerebrospinal fluid (CSF) biomarkers - Aß42, Tau, and phosphorylated Tau (pTau) - have been recently incorporated in the revised criteria for Alzheimer's disease (AD). However, their widespread clinical application lacks standardization. Pre-analytical sample handling and storage play an important role in the reliable measurement of these biomarkers across laboratories. AIM: In this study, we aim to surpass the efforts from previous studies, by employing a multicenter approach to assess the impact of less studied CSF pre-analytical confounders in AD-biomarkers quantification. METHODS: Four different centers participated in this study and followed the same established protocol. CSF samples were analyzed for three biomarkers (Aß42, Tau, and pTau) and tested for different spinning conditions [temperature: room temperature (RT) vs. 4°C; speed: 500 vs. 2000 vs. 3000 g], storage volume variations (25, 50, and 75% of tube total volume), as well as freezing-thaw cycles (up to five cycles). The influence of sample routine parameters, inter-center variability, and relative value of each biomarker (reported as normal/abnormal) was analyzed. RESULTS: Centrifugation conditions did not influence biomarkers levels, except for samples with a high CSF total protein content, where either non-centrifugation or centrifugation at RT, compared to 4°C, led to higher Aß42 levels. Reducing CSF storage volume from 75 to 50% of total tube capacity decreased Aß42 concentration (within analytical CV of the assay), whereas no change in Tau or pTau was observed. Moreover, the concentration of Tau and pTau appears to be stable up to five freeze-thaw cycles, whereas Aß42 levels decrease if CSF is freeze-thawed more than three times. CONCLUSION: This systematic study reinforces the need for CSF centrifugation at 4°C prior to storage and highlights the influence of storage conditions in Aß42 levels. This study contributes to the establishment of harmonized standard operating procedures that will help reducing inter-lab variability of CSF-AD biomarkers evaluation.

[Surgical management of Takayasu's arteritis with extensive vascular involvement and bilateral renal artery stenosis]. / Tratamento cirúrgico da arterite de takayasu com envolvimento vascular extenso e estenose bilateral das artérias renals.

Proximal renal artery stenosis, in association with stenoses and/or aneurysms of aorta and its branches, suggests a Takayasu's disease and is an important, treatable cause of hypertension in young people. A 29-year-old black woman presents with systodiastolic hypertension and suprasternal and abdominal bruits. An aortography disclosed multiple aneurysms and stenosis of the aorta and its main branches, and bilateral stenosis of renal arteries. The patient underwent an unusual and well-succeeded surgical procedure consisting in the creation of a "ventral aorta", a bypass from the ascending aorta down to the aortic bifurcation, and revascularization of both kidneys. Takayasu's disease frequently courses with extensive involvement of vasculature and bilateral renal stenosis. Renovascular hypertension is a major complication, contributing to the high mortality of this disease. Renal revascularization plays an important role in the modification of the natural history of Takayasu's disease and is essential for long-term survival and prevention of ischaemic renal failure.

[Lemierre's syndrome]. / Síndrome de Lemierre.

Lemierre's syndrome (LS) is an uncommon but potentially life-threatening complication of an anaerobic oropharyngeal infection, affecting young adults and adolescents. The disease is characterised by a septic thrombophlebitis of the internal jugular vein and "metastatic" infections, which can be followed by fulminant sepsis and rapid death. More recently, it has been reported a recrudescence of this condition, which could be attributable to alterations in antibiotic usage patterns. The authors report the case of a LS secondary to a bout of intense cough, a cause not yet described in the literature, highlighting the importance of a quick diagnosis and the institution of an appropriate therapy.