Multiple sclerosis (MS) is the most frequent demyelinating disease of the central nervous system. Although there is currently no definite cure for MS, new therapies have recently been developed based on a continuous search for new biomarkers. MS diagnosis relies on the integration of clinical, imaging and laboratory findings as there is still no singlepathognomonicclinical feature or diagnostic laboratory biomarker. The most commonly laboratory test used is the presence of immunoglobulin G oligoclonal bands (OCB) in cerebrospinal fluid of MS patients. This test is now included in the 2017 McDonald criteria as a biomarker of dissemination in time. Nevertheless, there are other biomarkers currently in use such as kappa free light chain, which has shown higher sensitivity and specificity for MS diagnosis than OCB. In addition, other potential laboratory tests involved in neuronal damage, demyelination and/or inflammation could be used for detecting MS. CSF and serum biomarkers have been reviewed for their use in MS diagnosis and prognosis to stablish an accurate and prompt MS diagnosis, crucial to implement an adequate treatment and to optimize clinical outcomes over time.

Objectives: Remote self-collected capillary blood samples have been proposed as alternative to venous blood samples as an aid in telemedicine. The aim of this work is to compare the preanalytical and analytical performance of these two types of samples and to study the stability of common measurands in capillary blood. Methods: Capillary and venous blood samples were collected in parallel from 296 patients in serum tubes to analyze 22 common biochemistry magnitudes after centrifugation and in EDTA tubes to analyze 15 hematologic magnitudes. Quality of the preanalytical process was assessed applying the model of quality indicator. 24 h stability at room temperature was studied by obtaining paired capillary samples. A questionnaire of assessment was conducted. Results: Mean hemolysis index was higher in capillary samples compared to venous blood samples (p<0.001). Regression analysis and difference analysis showed no bias for all studied biochemistry parameters and hematologic parameters, except mean corpuscular volume (MCV), between capillary and venous blood samples. Regarding sample stability, percentage deviation was higher than the corresponding minimum analytical performance specification for ferritin, vitamin D, hematocrit, MCV, mean corpuscular hemoglobin concentration, platelets distribution wide, mean platelet volume and basophils. Finger pricking was perceived as less painful (p<0.05) than venipuncture in participants who undergo more than one blood test per year. Conclusions: Capillary blood can be used as an alternative to venous blood for the studied parameters in automated common clinical analyzers. Cautious should be taken if samples are not analyzed within 24 h from the collection.

Liver fibrosis is the result of chronic liver injury of different etiologies produced by an imbalance between the synthesis and degeneration of the extracellular matrix and dysregulation of physiological mechanisms. Liver has a high regenerative capacity in the early stage of chronic diseases so a prompt liver fibrosis detection is important. Consequently, an easy and economic tool that could identify patients with liver fibrosis at the initial stages is needed. To achieve this, many non-invasive serum direct, such as hyaluronic acid or metalloproteases, and indirect biomarkers have been proposed to evaluate liver fibrosis. Also, there have been developed formulas that combine these biomarkers, some of them also introduce clinical and/or demographic parameters, like FIB-4, non-alcoholic fatty liver disease fibrosis score (NFS), enhance liver fibrosis (ELF) or Hepamet fibrosis score (HFS). In this manuscript we critically reviewed different serum biomarkers and formulas for their utility in the diagnosis and progression of liver fibrosis.

Multiple sclerosis (MS) diagnosis includes the presence of restricted oligoclonal bands (OCB) in cerebrospinal fluid (CSF), but it has several limitations, as it is an observer‐dependent time‐consuming technique and offers a dichotomous result. Thus kappa free light chains (KFLC) have emerged as a quantitative alternative. However, the cut‐off values for KFLC have not been well established yet and it is not clear if differences between sexes exist. We aim to evaluate these and to compare the diagnostic accuracy of KFLC concentrations and their related indexes versus OCB. For that purpose, paired CSF and serum samples were collected and immediately processed for albumin, total protein, immunoglobulins and OCB, then frozen at −20°C. KFLC was measured in a BN II (Siemens Healthineers, Germany). KFLC‐derived indexes were calculated. Diagnostic accuracy was evaluated by the area under the curve (AUC), Youden's index and odds ratio. From the 193 patients included, 56 were classified as MS according to the 2017 McDonald criteria. K‐index, Q KFLC and Reiber's diagram showed good accuracy in MS diagnosis when studied distinguishing between sexes, similar to OCB. Cut‐offs for K‐index and Q KFLC change substantially between sex having the highest AUC similar than OCB. A sex‐dependent algorithm combining the use of K‐index, Q KFLC and OCB yields the highest diagnostic accuracy. In conclusion, CSF KFLC measurement is a rapid, quantitative and easy‐to‐standardize tool that used through the proposed sex‐dependent algorithm may reduce the number of manual OCB tests performed.

Resumen: La fibrosis hepática se desarrolla como respuesta a la presencia de daño hepático crónico de diferentes etiologías, provocando un desequilibrio entre la síntesis y degeneración de la matriz extracelular y la desregulación de diversos mecanismos fisiológicos. En los estadios iniciales de las patologías crónicas, el hígado posee una elevada capacidad de regeneración, por lo que la detección temprana de la fibrosis hepática resulta esencial. En este contexto, es preciso contar con herramientas sencillas y económicas que permitan detectar la fibrosis hepática en sus fases iniciales. Para evaluar la fibrosis hepática, se han propuesto multitud de biomarcadores séricos no invasivos, tanto directos, como el ácido hialurónico o las metaloproteasas, como indirectos. Así mismo, se han desarrollado diversas fórmulas que combinan dichos biomarcadores junto con parámetros demográficos, como el índice FIB-4, el índice de fibrosis en la enfermedad de hígado graso no alcohólico (NFS, por sus siglas en inglés), la prueba ELF o el score de fibrosis Hepamet (HFS, por sus siglas en inglés). En el presente manuscrito, realizamos una revisión crítica del valor diagnóstico y pronóstico de los diferentes biomarcadores séricos y fórmulas actualmente existentes.