Varo, N. (Nerea)
- Publications
- item.page.relationships.isContributorAdvisorOfPublication
- item.page.relationships.isContributorOfPublication
5 results
Search Results
Now showing 1 - 5 of 5
- Evaluation of measured and calculated small dense low-density lipoprotein in capillary blood and association with the metabolic syndrome(Elsevier, 2024) Deza, S. (Sara); Beloqui, O. (Óscar); Colina, I. (Inmaculada); Varo, N. (Nerea); Maroto-García, J. (Julia); Gonzalez-Hernandez, A. (Alvaro); Mugueta, C. (Carmen); Martínez-Chávez, E. (Estéfani); Monreal, J.I. (José Ignacio)Background and aims: Small-dense-low-density-lipoprotein cholesterol (sdLDL-C) is proatherogenic and not commonly measured. The aims were to evaluate capillary blood and its stability for sdLDL-C measurement and measure sdLDL-C in patients with metabolic syndrome (MS). Methods: 182 patients were studied (49 with MS). sdLDL-C was measured by electrophoresis (LipoPrint®), direct measurement (Roche Diagnostics) and Sampson equation. Intima-media thickness (IMT) and presence of atheroma was evaluated. sdLDL-C was compared in paired venous and capillary blood according to CLSI-EP09c (n = 40). sdLDL-C stability was studied after 24 h at room temperature (RT). Results: sdLDL-C in capillary blood and venous blood showed agreement with the direct measurement (bias: 4.17 mg/dL, LOA 95 %:-5.66; 13.99) and estimation (bias:8.12 mg/dL, LOA 95 %:-8.59; 24.82). sdLDL-C is stable in capillary blood for 24 h at RT. The electrophoretic method yielded lower (p < 0.05) sdLDL-C than the equation or direct measurement. Patients with MS had (p < 0.05) higher sdLDL-C (%) than patients without MS. Patients with atheroma plaques had higher sdLDL-C (p < 0.05). Estimated sdLDL-C correlated with IMT (r = 0.259, p < 0.001). Conclusions: Capillary blood is an alternative to venous blood for sdLDL-C measurement and is stable for 24 h after collection. Estimated and directly measured sdLDL-C associate with the MS being accessible tools for cardiovascular risk assessment.
- Espectrometría de masas en los laboratorios clínicos de proteínas(2024) Mugueta, C. (Carmen); González, Á. (Álvaro); Deza, S. (Sara); Sin Autoridad; Puig, N. (Noemí); Varo, N. (Nerea)Joseph John Thomson fue un ingeniero y matemático inglés descubridor del electrón, que recibió el Premio Nobel de Física en 1906, el mismo año en que Santiago Ramón y Cajal recibía el de Medicina. Thomson ya describió en 1899 un instrumento parecido a un espectrómetro de masas. Fueron sus discípulos, Aston y Dempster, de la Universidad de Chicago, quienes construyeron en la década siguiente los primeros espectrómetros de masas tal y como se conocen en la actualidad. Desde entonces, la tecnología ha avanzado de manera extraordinaria, primero con la introducción de instrumentos de tiempo de vuelo o cuadrupolo. El electrospray resolvió después el problema de la ionización de proteínas de gran tamaño y amplió el rango de análisis, previamente restringido a compuestos pequeños. En su conferencia por el Premio Nobel de Química en 2002, Fenn, se refirió a esto como dotar de “alas de electrospray a elefantes moleculares”. Estas mejoras y otras posteriores como el Matrix Assisted Laser Desportion/Ionization (MALDI) y la trampa iónica, han convertido a la espectrometría de masas (EM) en una herramienta analítica potente, versátil, precisa y sensible cuyo uso se ha extendido a ámbitos muy diferentes, hasta finalmente llamar también a las puertas del Laboratorio Clínico. Hasta ahora, su uso en rutina en los laboratorios clínicos se ha restringido al análisis de fármacos, hormonas esteroideas y otros metabolitos. Sin embargo, por sus características, el espectro de potenciales aplicaciones de la EM es muy amplio. De hecho, en los últimos años, su uso se ha extendido al análisis de moléculas más grandes como las proteínas, incluyendo la inmunoglobulina monoclonal empleada como biomarcador para el diagnóstico y seguimiento de las gammapatías monoclonales (GM).
- Impact of ultra-low temperature long-term storage on the preanalytical variability of twentyone common biochemical analytes(2022) Alegre-Martinez, E. (Estibaliz); Varo, N. (Nerea); Fernández-Calle, P. (Pilar); Gonzalez-Hernandez, A. (Alvaro); Calleja-Aznárez, S. (Sofía)Objectives: Retrospective studies frequently assume analytes long-term stability at ultra-low temperatures. However, these storage conditions, common among biobanks and research, may increase the preanalytical variability, adding a potential uncertainty to the measurements. This study is aimed to evaluate long-term storage stability of different analytes at <−70 °C and to assess its impact on the reference change value formula. Methods: Twenty-one analytes commonly measured in clinical laboratories were quantified in 60 serum samples. Samples were immediately aliquoted and frozen at <−70 °C, and reanalyzed after 11 ± 3.9 years of storage. A change in concentration after storage was considered relevant if the percent deviation from the baseline measurement was significant and higher than the analytical performance specifications. Results: Preanalytical variability (CVP) due to storage, determined by the percentage deviation, showed a noticeable dispersion. Changes were relevant for alanine aminotransferase, creatinine, glucose, magnesium, potassium, sodium, total bilirubin and urate. No significant differences were found in aspartate aminotransferase, calcium, carcinoembryonic antigen, cholesterol, C-reactive protein, direct bilirubin, free thryroxine, gammaglutamyltransferase, lactate dehydrogenase, prostatespecific antigen, triglycerides, thyrotropin, and urea. As nonnegligible, CVP must remain included in reference change value formula, which was modified to consider whether one or two samples were frozen. Conclusions: After long-term storage at ultra-low temperatures, there was a significant variation in some analytes that should be considered. We propose that reference change value formula should include the CVP when analyzing samples stored in these conditions.
- Comparison of six commercial serum exosome isolation methods suitable for clinical laboratories. Effect in cytokine analysis(2019) Alegre-Martinez, E. (Estibaliz); Rebmann, V. (Vera); Varo, N. (Nerea); Gonzalez-Hernandez, A. (Alvaro); Mateos, B. (Beatriz); Macías, M. (Mónica); Perez-García, J. (José)Background: Exosomes are nanovesicles released by cells that can be detected in blood. Exosomes contain several molecules, such as cytokines that have potential utility as disease biomarkers. The aim of the present work is to compare six different commercial kits suitable for the clinical laboratory in relation to the efficiency and purity of exosome isolation, and their effect in subsequent cytokines analysis. Methods: Serum exosomes were obtained from 10 volunteers using six commercial kits: exoEasy, ExoQuick, Exo-spin, ME kit, ExoQuick Plus and Exo-Flow. Exosome concentrations and size distributions were quantified by nanoparticle tracking analysis. Exosome markers CD63, CD9 and TSG101 were determined by Western blot. ApoB and albumin were measured using nephelometry. S100A9, CXCL5 and CXCL12 were measured using a Luminex assay. Results: The concentration of particles obtained between different kits varied by a factor of 100. There was no correlation in particle concentrations extracted between different kits, except between ExoQuick and Exo-Flow. The highest exosome purity was achieved with ExoQuick Plus and exoEasy, while the lowest were achieved with ME and ExoQuick. Albumin was present in all exosome extracts analyzed and ApoB in all except those extracted with Exo-Flow and ME. Cytokine detection varied depending on the purification kit used and there was no correlation in cytokine concentrations between samples obtained with different kits. Conclusions: Both the sample and the type of commercial kit used affect the efficiency and purity of exosome isolation. In addition, the exosome purification method deeply affects the capability to detect and quantify cytokines.
- Prenatal exposure to perfluoroalkyl substances associated with increased susceptibility to liver injury in children(Wiley, 2020) Papadopoulou, E. (Eleni); García, E. (Erika); Wright, J. (John); Haug, L.S. (Line Smastuen); Chatzi, L. (Lida); Vos, M.B. (Miriam B.); Robinson, O. (Oliver); Roumeliotaki, T. (Theano); Varo, N. (Nerea); Conti, D.V. (David V.); Uppal, K. (Karan); Vafeiadi, M. (Marina); Maitre, L. (Léa); Heude, B. (Barbara); Fernández-Barrés, S. (Silvia); Gómez-Urquiza, J. (José); Jin, R. (Ran); McEachan, R.R.C. (Rosemary R. C.); McConnell, R. (Rob); Casas, M. (Maribel); Fossati, S. (Serena); Grazuleviciene, R. (Regina); Valvi, D. (Damaskini); Keun, H.C. (Hector C.); Basagana, X. (Xavier); Margetaki, K. (Katerina); Vrijheid, M. (Martine); Berhane, K.T. (Kiros T.); Stratakis, N. (Nikos); Andrusaityte, S. (Sandra); Zhao, Y. (Yinqi); Siskos, A.P. (Alexandros P.)BACKGROUND AND AIMS: Per- and polyfluoroalkyl substances (PFAS) are widespread and persistent pollutants that have been shown to have hepatotoxic effects in animal models. However, human evidence is scarce. We evaluated how prenatal exposure to PFAS associates with established serum biomarkers of liver injury and alterations in serum metabolome in children. APPROACH AND RESULTS: We used data from 1,105 mothers and their children (median age, 8.2 years; interquartile range, 6.6-9.1) from the European Human Early-Life Exposome cohort (consisting of six existing population-based birth cohorts in France, Greece, Lithuania, Norway, Spain, and the United Kingdom). We measured concentrations of perfluorooctane sulfonate, perfluorooctanoate, perfluorononanoate, perfluorohexane sulfonate, and perfluoroundecanoate in maternal blood. We assessed concentrations of alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase in child serum. Using Bayesian kernel machine regression, we found that higher exposure to PFAS during pregnancy was associated with higher liver enzyme levels in children. We also measured child serum metabolomics through a targeted assay and found significant perturbations in amino acid and glycerophospholipid metabolism associated with prenatal PFAS. A latent variable analysis identified a profile of children at high risk of liver injury (odds ratio, 1.56; 95% confidence interval, 1.21-1.92) that was characterized by high prenatal exposure to PFAS and increased serum levels of branched-chain amino acids (valine, leucine, and isoleucine), aromatic amino acids (tryptophan and phenylalanine), and glycerophospholipids (phosphatidylcholine [PC] aa C36:1 and Lyso-PC a C18:1). CONCLUSIONS: Developmental exposure to PFAS can contribute to pediatric liver injury. (Hepatology 2020;72:1758-1770).