Aportación del cociente ABeta1-42/ABeta1-40 al concepto enfermedad de Alzheimer contribuye al deterioro cognitivo leve / Role of the ABeta1-42/ABeta1-40 ratio in the concept Alzheimers disease contributes to mild cognitive impairment

Introducción: La demostración de amiloidosis cerebral, mediante la alteración de los niveles del péptido Aß1-42 o del cociente Aß1-42/Aß1-40, es condición necesaria para aceptar la presencia de la enfermedad de Alzheimer (EA), según los criterios de 2018 del National Institute on Aging y la Alzheimers Association (NIA-AA 2018). Objetivo: Calcular la ganancia diagnóstica que supone el cálculo del cociente Aß1-42/Aß1-40 respecto al uso exclusivo de los niveles del péptido Aß42 para identificar a los pacientes que pertenecen al grupo EA contribuye al deterioro cognitivo leve (DCL), según los criterios NIA-AA 2018. Pacientes y métodos: Entre abril de 2018 y abril de 2020, incluimos a 62 pacientes con DCL, según los criterios de Petersen de 2006, a los que se les realizó una punción lumbar dentro del proceso diagnóstico. El líquido cefalorraquídeo se analizó mediante la metodología inmunoquimioluminiscente, que permite cuantificar los biomarcadores core de la EA en el líquido cefalorraquídeo y el péptido Aß1-40. Resultados: Cuarenta y dos pacientes (67,7%) presentaron criterios de EA contribuye a DCL. La utilización del cociente Aß1-42/Aß1-40, respecto a la utilización exclusiva de los niveles de Aß1-42, supone una ganancia diagnóstica del 19% (ocho pacientes) para establecer la presencia de amiloidosis en el líquido cefalorraquídeo de estos pacientes. Conclusión: El cálculo del cociente Aß1-42/Aß1-40 supone una ganancia diagnóstica clara para identificar a los pacientes que pertenecen al grupo EA contribuye al DCL’, por lo que aconsejamos su utilización, como se viene recogiendo en la bibliografía más reciente. En nuestro conocimiento, es la primera publicación de estas características en lengua española.(AU)

Introduction: Evidence of cerebral amyloidosis, by altered levels of the peptide Aβ1-42 or the Aβ1-42/Aβ1-40 ratio, is a necessary condition to accept the presence of Alzheimer’s disease (AD), according to the 2018 criteria of the National Institute on Aging and Alzheimer’s Association (NIA-AA 2018). Aim: To calculate the diagnostic gain obtained from calculating the Aβ1-42/Aβ1-40 ratio with respect to the exclusive use of the peptide Aβ42 to identify patients belonging to the ‘Alzheimer’s disease contributes to mild cognitive impairment (MCI)’ group, according to NIA-AA 2018 criteria. Patients and methods: Between April 2018 and April 2020, we included 62 patients with MCI, according to Petersen’s 2006 criteria, who underwent lumbar puncture as part of the diagnostic process. Cerebrospinal fluid was analysed using the immunochemiluminescence methodology, which makes it possible to quantify core AD biomarkers in cerebrospinal fluid and the peptide Aβ1-40. Results: Forty-two patients (67.7%) presented criteria supporting ‘AD contributes to MCI’. The use of the Aβ1-42/Aβ1-40 ratio, compared to the exclusive use of Aβ1-42 levels, represents a diagnostic gain of 19% (eight patients) to establish the presence of amyloidosis in the cerebrospinal fluid of these patients. Conclusion: The calculation of the Aβ1-42/Aβ1-40 ratio is a clear diagnostic gain for identifying patients belonging to the ‘AD contributes to MCI’ group, and we therefore recommend its use, as reported in the most recent literature. To our knowledge, this is the first publication of its kind in Spanish.(AU)

[Role of the Aß1-42/Aß1-40 ratio in the concept 'Alzheimer's disease contributes to mild cognitive impairment']. / Aportación del cociente Aß1-42/Aß1-40 al concepto 'enfermedad de Alzheimer contribuye al deterioro cognitivo leve'.

INTRODUCTION: Evidence of cerebral amyloidosis, by altered levels of the peptide Aß1-42 or the Aß1-42/Aß1-40 ratio, is a necessary condition to accept the presence of Alzheimer's disease (AD), according to the 2018 criteria of the National Institute on Aging and Alzheimer's Association (NIA-AA 2018). AIM: To calculate the diagnostic gain obtained from calculating the Aß1-42/Aß1-40 ratio with respect to the exclusive use of the peptide Aß42 to identify patients belonging to the 'Alzheimer's disease contributes to mild cognitive impairment (MCI)' group, according to NIA-AA 2018 criteria. PATIENTS AND METHODS: Between April 2018 and April 2020, we included 62 patients with MCI, according to Petersen's 2006 criteria, who underwent lumbar puncture as part of the diagnostic process. Cerebrospinal fluid was analysed using the immunochemiluminescence methodology, which makes it possible to quantify core AD biomarkers in cerebrospinal fluid and the peptide Aß1-40. RESULTS: Forty-two patients (67.7%) presented criteria supporting 'AD contributes to MCI'. The use of the Aß1-42/Aß1-40 ratio, compared to the exclusive use of Aß1-42 levels, represents a diagnostic gain of 19% (eight patients) to establish the presence of amyloidosis in the cerebrospinal fluid of these patients. CONCLUSION: The calculation of the Aß1-42/Aß1-40 ratio is a clear diagnostic gain for identifying patients belonging to the 'AD contributes to MCI' group, and we therefore recommend its use, as reported in the most recent literature. To our knowledge, this is the first publication of its kind in Spanish.

TITLE: Aportación del cociente Aß1-42/Aß1-40 al concepto 'enfermedad de Alzheimer contribuye al deterioro cognitivo leve'.Introducción. La demostración de amiloidosis cerebral, mediante la alteración de los niveles del péptido Aß1-42 o del cociente Aß1-42/Aß1-40, es condición necesaria para aceptar la presencia de la enfermedad de Alzheimer (EA), según los criterios de 2018 del National Institute on Aging y la Alzheimer's Association (NIA-AA 2018). Objetivo. Calcular la ganancia diagnóstica que supone el cálculo del cociente Aß1-42/Aß1-40 respecto al uso exclusivo de los niveles del péptido Aß42 para identificar a los pacientes que pertenecen al grupo 'EA contribuye al deterioro cognitivo leve (DCL)', según los criterios NIA-AA 2018. Pacientes y métodos. Entre abril de 2018 y abril de 2020, incluimos a 62 pacientes con DCL, según los criterios de Petersen de 2006, a los que se les realizó una punción lumbar dentro del proceso diagnóstico. El líquido cefalorraquídeo se analizó mediante la metodología inmunoquimioluminiscente, que permite cuantificar los biomarcadores core de la EA en el líquido cefalorraquídeo y el péptido Aß1-40. Resultados. Cuarenta y dos pacientes (67,7%) presentaron criterios de 'EA contribuye a DCL'. La utilización del cociente Aß1-42/Aß1-40, respecto a la utilización exclusiva de los niveles de Aß1-42, supone una ganancia diagnóstica del 19% (ocho pacientes) para establecer la presencia de amiloidosis en el líquido cefalorraquídeo de estos pacientes. Conclusión. El cálculo del cociente Aß1-42/Aß1-40 supone una ganancia diagnóstica clara para identificar a los pacientes que pertenecen al grupo 'EA contribuye al DCL', por lo que aconsejamos su utilización, como se viene recogiendo en la bibliografía más reciente. En nuestro conocimiento, es la primera publicación de estas características en lengua española.

[Frequent involvement of the amyloid pathway in prodromal dementia with Lewy bodies]. / Frecuente alteracion de la via amiloide en la demencia con cuerpos de Lewy prodromica.

INTRODUCTION: Lewy body dementia (LBD) is the most frequent of the degenerative dementias, after Alzheimer's disease. AIM: To analyse the core biomarkers of Alzheimer's disease in the cerebrospinal fluid of exclusively Hispanic patients with prodromal LBD, in order to determine whether there is involvement of the amyloid pathway or the tau pathway. PATIENTS AND METHODS: Between 2008 and 2017 we included 430 patients with mild cognitive impairment according to Petersen criteria, from three hospitals in the province of Alicante. They underwent clinical check-ups every 6-12 months to evaluate their clinical stability or their progression to dementia using current clinical criteria. Among other complementary tests, biomarkers for Alzheimer's disease in the cerebrospinal fluid were analysed. RESULTS: Of all the patients included, 26 developed LBD and 29 remained stable for at least five years, and were thus considered as a reference. In this group only five (17%) had Abeta(1-42) protein values below normal, whereas 16 (55%) of the patients with LBD had altered levels. No differences were found in the levels of tau protein. On comparing the LBD groups with and without amyloidosis, differences were only found in the levels of Abeta(1-42) protein. CONCLUSIONS: We highlight the frequent presence of amyloid pathology in prodromal LBD in our population, and the probable involvement of different metabolic pathways in the same clinically defined dementia.

TITLE: Frecuente alteracion de la via amiloide en la demencia con cuerpos de Lewy prodromica.Introduccion. La demencia con cuerpos de Lewy (DCLW) es la mas frecuente de las degenerativas, despues de la enfermedad de Alzheimer. Objetivo. Analizar los biomarcadores core de la enfermedad de Alzheimer en el liquido cefalorraquideo de pacientes exclusivamente hispanos con DCLW prodromica, para conocer si existe alteracion de la via amiloide o de la via tau. Pacientes y metodos. Entre 2008-2017 incluimos a 430 pacientes con deterioro cognitivo leve segun los criterios de Petersen, procedentes de tres hospitales de la provincia de Alicante. Se les realizaron revisiones clinicas cada 6-12 meses para evaluar su estabilidad clinica o la progresion a demencia utilizando los criterios clinicos vigentes. Entre otras pruebas complementarias se analizaron los biomarcadores de enfermedad de Alzheimer en el liquido cefalorraquideo. Resultados. Entre todos los pacientes incluidos, 26 desarrollaron DCLW y 29 se mantuvieron estables durante al menos cinco años, por lo que los consideramos como referencia. En este grupo solamente cinco (17%) tenian valores de proteina Abeta(1-42) inferiores a la normalidad, mientras que 16 (55%) de los pacientes con DCLW tenian niveles alterados. No se encontraron diferencias en los niveles de las proteinas tau. Al comparar los grupos con DCLW con y sin amiloidosis solamente encontramos diferencias en los niveles de proteina Abeta(1-42). Conclusiones. Destacamos la frecuente presencia de patologia amiloidea en la DCLW prodromica en nuestra poblacion y la probable alteracion de diferentes vias metabolicas en una misma demencia clinicamente definida.

Diagnostic Validity Comparison Between Criteria Based on CSF Alzheimer's Disease Biomarkers.

AIM: To compare the diagnostic validity of NIA-AA criteria, for AD CSF biomarkers, with our own new criteria. MATERIALS AND METHODS: Between 2008 and 2011, 170 patients with Mild Cognitive Impairment (MCI) were included. CSF levels of Aß1-42, T-tau, P-tau181, and ratios of T-tau/Aß1-42 and P-tau181/Aß1-42 were analyzed. In our criteria, we considered 3 or more abnormal variables indicative of a high likelihood of MCI due to AD. RESULTS: After a clinical follow-up of 4.5 ± 1.2 years, 44 patients remained stable, 95 developed AD, 15 other forms of dementia, 7 died and 9 received other diagnoses. Using the NIA-AA criteria and our own criteria, the diagnostic validity of the CSF biomarkers was 58% versus 85%, specificity 84% versus 72%, PPV 82% versus 79% and NPV 61% versus 79%. CONCLUSION: The inclusion of the ratios in diagnostic criteria increases sensitivity and NPV for the diagnosis of MCI due to AD.

Influence of APOE Genotype on Alzheimer's Disease CSF Biomarkers in a Spanish Population.

OBJECTIVES: To evaluate the association between apolipoprotein E (APOE) genotype and cerebrospinal fluid (CSF) levels of Alzheimer's disease (AD) biomarkers and to study the influence of APOE genotype on the development of AD in a Spanish population. MATERIAL AND METHODS: The study comprised 29 amnestic mild cognitive impairment (MCI) patients and 27 control subjects. Using ELISA methodology, CSF biomarkers and tau/Aß ratios were obtained. ANOVA and adjusted odds ratios were calculated. RESULTS: We observed the effect of APOE genotype and age on CSF AD variables. The progression to AD was more clearly influenced by CSF AD variables than by age or APOE status. CONCLUSIONS: APOE status influences CSF AD variables. However, the presence of APOE ε4 does not appear to be a deterministic factor for the development of AD, because CSF variables have a greater influence on progression to the disease. These results confirm previous observations and, to our knowledge, are the first published in a Spanish population.

Comparación de la capacidad diagnóstica precoz de los biomarcadores de la enfermedad de Alzheimer en resonancia magnética cerebral y líquido cefalorraquídeo / A comparison of early diagnostic utility of Alzheimer disease biomarkers in brain magnetic resonance and cerebrospinal fluid

Introducción: Nuestros objetivos fueron comparar la capacidad de diagnóstico precoz de los biomarcadores (BMC) de enfermedad de Alzheimer (EA) en LCR y RM cerebral, en condiciones posibles de nuestra práctica clínica y, además, conocer la precisión diagnóstica de la combinación de ambas técnicas. Métodos: Entre 2008 y 2009, estudiamos a 30 pacientes con deterioro cognitivo leve (DCL) mediante RM cerebral de 1,5 teslas y análisis de BMC de EA en el LCR. Las RM fueron valoradas por 2 neurorradiólogos, atendiendo a la escala visual de Korf (2004). Los BMC de EA en LCR se analizaron mediante reactivos INNOTEST para proteínas A 1-42, total-tau y fosfo-tau. Se evaluó la evolución clínica (según criterios NINCDS-ADRDA) a los 2 a˜nos tras la inclusión. Resultados: Entre los 30 pacientes iniciales, 15 evolucionaron a EA (criterios NINCDS-ADRDA) a los 2 a˜nos de la inclusión. La capacidad predictiva de los BMC en LCR (RR 2,7; IC del 95%, 1,1-6,7; p < 0,01) es superior a los de RM (RR 1,5; IC del 95%, 0,7-3,4; p < 0,2), y la combinación de ambas técnicas alcanza una sensibilidad y valor predictivo negativo del 100%. La normalidad de ambas pruebas complementarias descartó al 100% el desarrollo de EA, en los 2 a˜nos siguientes a la realización de las mismas. Conclusiones: Siguiendo nuestra metodología, la precisión diagnóstica de los BMC en LCR es superior a los de la RM para el diagnóstico precoz de EA. La combinación de ambas técnicasconsigue una precisión diagnóstica muy alta, tanto para diagnosticar como para excluir precozmente EA, en pacientes con DCL

Introduction: The goals of this study were to compare the early diagnostic utility of Alzheimer disease biomarkers in the CSF with those in brain MRI in conditions found in our clinical practice, and to ascertain the diagnostic accuracy of both techniques used together. Methods: Between 2008 and 2009, we included 30 patients with mild cognitive impairment (MCI) who were examined using 1.5 Tesla brain MRI and AD biomarker analysis in CSF. MRI studies were evaluated by 2 radiologists according to the Korf s visual scale. CSF biomarkers were analysed using INNOTEST reagents for A 1-42, total-tau and phospho-tau181p. We evaluated clinical changes 2 years after inclusion. Results: By 2 years after inclusion, 15 of the original 30 patients (50%) had developed AD (NINCDS-ADRA criteria). The predictive utility of AD biomarkers in CSF (RR 2.7; 95% CI, 1.1-6.7; P < .01) was greater than that of MRI (RR 1.5; 95% CI 95%, 0.7-3.4; P < .2); using both techniques together yielded a sensitivity and a negative predictive value of 100%. Normal results on both complementary tests ruled out progression to AD (100%) within 2 years of inclusion. Conclusions: Our results show that the diagnostic accuracy of biomarkers in CSF is higher than that of biomarkers in MRI. Combined use of both techniques is highly accurate for either early diagnosis or exclusion of AD in patients with MCI

A comparison of early diagnostic utility of Alzheimer disease biomarkers in brain magnetic resonance and cerebrospinal fluid.

INTRODUCTION: The goals of this study were to compare the early diagnostic utility of Alzheimer disease biomarkers in the CSF with those in brain MRI in conditions found in our clinical practice, and to ascertain the diagnostic accuracy of both techniques used together. METHODS: Between 2008 and 2009, we included 30 patients with mild cognitive impairment (MCI) who were examined using 1.5 Tesla brain MRI and AD biomarker analysis in CSF. MRI studies were evaluated by 2 radiologists according to the Korf́s visual scale. CSF biomarkers were analysed using INNOTEST reagents for Aß1-42, total-tau and phospho-tau181p. We evaluated clinical changes 2 years after inclusion. RESULTS: By 2 years after inclusion, 15 of the original 30 patients (50%) had developed AD (NINCDS-ADRA criteria). The predictive utility of AD biomarkers in CSF (RR 2.7; 95% CI, 1.1-6.7; P<.01) was greater than that of MRI (RR 1.5; 95% CI 95%, 0.7-3.4; P<.2); using both techniques together yielded a sensitivity and a negative predictive value of 100%. Normal results on both complementary tests ruled out progression to AD (100%) within 2 years of inclusion. CONCLUSIONS: Our results show that the diagnostic accuracy of biomarkers in CSF is higher than that of biomarkers in MRI. Combined use of both techniques is highly accurate for either early diagnosis or exclusion of AD in patients with MCI.