Diagnostic performance of plasma pTau217, pTau181, Aß1-42 and Aß1-40 in the LUMIPULSE automated platform for the detection of Alzheimer disease.

BACKGROUND: Recently developed blood markers for Alzheimer's disease (AD) detection have high accuracy but usually require ultra-sensitive analytic tools not commonly available in clinical laboratories, and their performance in clinical practice is unknown. METHODS: We analyzed plasma samples from 290 consecutive participants that underwent lumbar puncture in routine clinical practice in a specialized memory clinic (66 cognitively unimpaired, 130 participants with mild cognitive impairment, and 94 with dementia). Participants were classified as amyloid positive (A +) or negative (A-) according to CSF Aß1-42/Aß1-40 ratio. Plasma pTau217, pTau181, Aß1-42 and Aß1-40 were measured in the fully-automated LUMIPULSE platform. We used linear regression to compare plasma biomarkers concentrations between A + and A- groups, evaluated Spearman's correlation between plasma and CSF and performed ROC analyses to assess their diagnostic accuracy to detect brain amyloidosis as determined by CSF Aß1-42/Aß1-40 ratio. We analyzed the concordance of pTau217 with CSF amyloidosis. RESULTS: Plasma pTau217 and pTau181 concentration were higher in A + than A- while the plasma Aß1-42/Aß1-40 ratio was lower in A + compared to A-. pTau181 and the Aß1-42/Aß1-40 ratio showed moderate correlation between plasma and CSF (Rho = 0.66 and 0.69, respectively). The areas under the ROC curve to discriminate A + from A- participants were 0.94 (95% CI 0.92-0.97) for pTau217, and 0.88 (95% CI 0.84-0.92) for both pTau181 and Aß1-42/Aß1-40. Chronic kidney disease (CKD) was related to increased plasma biomarker concentrations, but ratios were less affected. Plasma pTau217 had the highest fold change (× 3.2) and showed high predictive capability in discriminating A + from A-, having 4-7% misclassification rate. The global accuracy of plasma pTau217 using a two-threshold approach was robust in symptomatic groups, exceeding 90%. CONCLUSION: The evaluation of blood biomarkers on an automated platform exhibited high diagnostic accuracy for AD pathophysiology, and pTau217 showed excellent diagnostic accuracy to identify participants with AD in a consecutive sample representing the routine clinical practice in a specialized memory unit.

Effects of storage conditions on the stability of blood-based markers for the diagnosis of Alzheimer's disease.

OBJECTIVES: Alzheimer's disease (AD) is considered the most common cause of dementia in older people. Recently, blood-based markers (BBM) Aß1-42, Aß1-40, and phospho Tau181 (p-Tau181) have demonstrated the potential to transform the diagnosis and prognostic assessment of AD. Our aim was to investigate the effect of different storage conditions on the quantification of these BBM and to evaluate the interchangeability of plasma and serum samples. METHODS: Forty-two individuals with some degree of cognitive impairment were studied. Thirty further patients were retrospectively selected. Aß1-42, Aß1-40, and p-Tau181 were quantified using the LUMIPULSE-G600II automated platform. To assess interchangeability between conditions, correction factors for magnitudes that showed strong correlations were calculated, followed by classification consistency studies. RESULTS: Storing samples at 4 °C for 8-9 days was associated with a decrease in Aß fractions but not when stored for 1-2 days. Using the ratio partially attenuated the pre-analytical effects. For p-Tau181, samples stored at 4 °C presented lower concentrations, whereas frozen samples presented higher ones. Concerning classification consistency in comparisons that revealed strong correlations (p-Tau181), the percentage of total agreement was greater than 90 % in a large number of the tested cut-offs values. CONCLUSIONS: Our findings provide relevant information for the standardization of sample collection and storage in the analysis of AD BBM in an automated platform. This knowledge is crucial to ensure their introduction into clinical settings.

Diagnostic performance of plasma pTau 217, pTau 181, Aß 1-42 and Aß 1-40 in the LUMIPULSE automated platform for the detection of Alzheimer disease.

BACKGROUND: Recently developed blood markers for Alzheimer's disease (AD) detection have high accuracy but usually require ultra-sensitive analytic tools not commonly available in clinical laboratories, and their performance in clinical practice is unknown. METHODS: We analyzed plasma samples from 290 consecutive participants that underwent lumbar puncture in routine clinical practice in a specialized memory clinic (66 cognitively unimpaired, 130 participants with mild cognitive impairment, and 94 with dementia). Participants were classified as amyloid positive (A+) or negative (A-) according to CSF Aß1-42/Aß1-40 ratio. Plasma pTau217, pTau181, Aß1-42 and Aß1-40 were measured in the fully-automated LUMIPULSE platform. We used linear regression to compare plasma biomarkers concentrations between A + and A- groups, evaluated Spearman's correlation between plasma and CSF and performed ROC analyses to assess their diagnostic accuracy to detect brain amyloidosis as determined by CSF Aß1-42/Aß1-40 ratio. We analyzed the potential of pTau217 to predict amyloidosis in CSF. RESULTS: Plasma pTau217 and pTau181 concentration were higher in A + than A- while the plasma Aß1-42/Aß1-40 ratio was lower in A + compared to A-. pTau181 and the Aß1-42/Aß1-40 ratio showed moderate correlation between plasma and CSF (Rho = 0.66 and 0.69, respectively). The areas under the ROC curve to discriminate A + from A- participants were 0.94 (95% CI 0.92-0.97) for pTau217, and 0.88 (95% CI 0.84-0.92) for both pTau181 and Aß1-42/Aß1-40. Chronic kidney disease (CKD) was related to increased plasma biomarker concentrations, but ratios were less affected. Plasma pTau217 had the highest fold change (x4.2) and showed high predictive capability in discriminating A + from A-, having 4-7% misclassification rate. The global accuracy of plasma pTau217 using a two-threshold approach was robust in symptomatic groups, exceeding 90%. CONCLUSION: The evaluation of blood biomarkers on an automated platform exhibited high diagnostic accuracy for AD pathophysiology, and pTau217 showed excellent diagnostic accuracy to identify participants with AD in a consecutive sample representing the routine clinical practice in a specialized memory unit.

Factores asociados al pronóstico funcional de pacientes con ictus isquémico agudo sometidos a trombectomía / Associated factors with functional prognosis of patients with acute ischemic stroke undergoing thrombectomy

Introducción: La trombectomía mecánica (TM) ha supuesto un cambio en la historia natural del ictus isquémico. Nos planteamos conocer factores asociados al pronóstico de los pacientes con ictus agudo tratados mediante TM en un hospital de tercer nivel de España.MétodosEstudio trasversal en 198 pacientes sometidos a TM por ictus isquémico agudo entre 2012 y 2020. Analizamos datos demográficos, factores de riesgo cerebrovascular, factores clínicos y radiológicos. Resultado valorado a los 90 días según la escala Rankin modificada (mRS), siendo favorable un mRS≤2 y desfavorable mRS≥3.ResultadosEdad media de 67,7±13,5 años, siendo el 50,5% mujeres. La hipertensión fue el factor de riesgo cerebrovascular más prevalente (65,7%). El valor National Institute of Health Stroke Scale (NIHSS) promedio basal fue 17,0(8,0;22,0). El 40,9% de los casos también recibió tratamiento fibrinolítico intravenoso. El 66,7% fueron realizados bajo sedación consciente. En promedio se realizaron 2 pases de TM, con una mediana de duración de 41 minutos. En el 79,9% la recanalización fue exitosa y el 59,5% presentaron un mRS≤2 a los 90 días. La edad, la DT2, el número de pases y la duración del procedimiento se asociaron con mRS≥3. La recanalización exitosa se asoció a un mRS≤2. Los modelos de regresión logística confirmaron la tendencia para edad (OR:1,56; IC%:1,11;2,20), DT2 (OR:3,51; IC%:1,38;8,97) y recanalización exitosa (OR:0,07; IC%:0,02;0,28).ConclusiónLa edad, la DT2 y el fracaso en la recanalización aumentan el riesgo de un resultado desfavorable a los 90 días en pacientes con ictus isquémico sometidos a TM. La duración de la intervención debería ser considerado como un posible factor pronóstico. (AU)

Introduction: Mechanical thrombectomy (MT) has meant a change in natural history of acute ischemic stroke. Our aim is to assess the possible association between different factors and prognosis in patients treated with MT in a third degree Spanish hospital.MethodsCross-sectional study including 198 patients underwent MT because of acute ischemic stroke between 2012 and 2020. Sociodemographic, vascular risk factors (VRF) and clinical-radiologic factors were recorded. Functional outcome was evaluated based on modified Rankin Scale (mRS) at 90 days, being mRS≤2 favorable and mRS≥3 unfavorable outcome.ResultsMean age 67.7±13.5 years, 50.5% women. Arterial hypertension was the most prevalent VRF (65.7%). National Institute of Health Stroke Scale (NIHSS) median value at admission was 17.0 (8.0; 22.0). 40.9% of cases also received fibrinolytic treatment. Conscious sedation was performed in 66.7% patients. Median passes of MT were 2, and median duration 41min. Successful recanalization was achieved in 79.9% and mRS≤2 at 90 days was registered at 59.5% cases. Age, type 2 diabetes (T2D), number of MT passes and procedure duration were associated with mRS≥3. Successful recanalization was associated with mRS≤2. Regression model confirmed these associations in age (OR: 1.56CI%: 1.11; 2.20); T2D (OR: 3.51CI%: 1.38; 8.97) and successful recanalization (OR: 0.07CI%: 0.02; 0.28).ConclusionAge, T2D and failed recanalization increase risk for unfavorable outcome at 90 days in patients with AIS treated with MT. Procedure time duration should be considered as a possible determinant factor in functional outcome. (AU)

Associated factors with functional prognosis of patients with acute ischemic stroke undergoing thrombectomy. / Factores asociados al pronóstico funcional de pacientes con ictus isquémico agudo sometidos a trombectomía.

INTRODUCTION: Mechanical thrombectomy (MT) has meant a change in natural history of acute ischemic stroke. Our aim is to assess the possible association between different factors and prognosis in patients treated with MT in a third degree Spanish hospital. METHODS: Cross-sectional study including 198 patients underwent MT because of acute ischemic stroke between 2012 and 2020. Sociodemographic, vascular risk factors (VRF) and clinical-radiologic factors were recorded. Functional outcome was evaluated based on modified Rankin Scale (mRS) at 90 days, being mRS≤2 favorable and mRS≥3 unfavorable outcome. RESULTS: Mean age 67.7±13.5 years, 50.5% women. Arterial hypertension was the most prevalent VRF (65.7%). National Institute of Health Stroke Scale (NIHSS) median value at admission was 17.0 (8.0; 22.0). 40.9% of cases also received fibrinolytic treatment. Conscious sedation was performed in 66.7% patients. Median passes of MT were 2, and median duration 41min. Successful recanalization was achieved in 79.9% and mRS≤2 at 90 days was registered at 59.5% cases. Age, type 2 diabetes (T2D), number of MT passes and procedure duration were associated with mRS≥3. Successful recanalization was associated with mRS≤2. Regression model confirmed these associations in age (OR: 1.56CI%: 1.11; 2.20); T2D (OR: 3.51CI%: 1.38; 8.97) and successful recanalization (OR: 0.07CI%: 0.02; 0.28). CONCLUSION: Age, T2D and failed recanalization increase risk for unfavorable outcome at 90 days in patients with AIS treated with MT. Procedure time duration should be considered as a possible determinant factor in functional outcome.