Circulating extracellular vesicles in Systemic Lupus Erythematosus: physicochemical properties and phenotype.

OBJECTIVE: This study aimed to identify the physicochemical and phenotypic characteristics of circulating Extracellular Vesicles (EVs) in the plasma of patients with SLE, with or without Lupus Nephritis (LN), and their potential utility as disease biomarkers. METHODS: Plasma-circulating EVs were concentrated using differential centrifugation from adult female patients (n=38) who met the 'American College of Rheumatology/European Alliance of Associations for Rheumatology 2019' criteria for SLE diagnosis with (LN) or without LN (nLN), confirmed by renal biopsy. Controls (n=18) were healthy volunteers matched by gender and similar age. The structure, size and Energy Dispersion Spectrum (EDS) of EVs were observed by electron microscopy. The surface charge and size distribution were evaluated using dynamic light scattering. The counts and phenotype of EVs from patients (SLE-EVs) and controls (Ctrl-EVs) were obtained using flow cytometry. Non-parametric statistical tests and exploratory analysis of multiple variables were performed. The discriminatory power of some variables as potential biomarkers of the disease was also evaluated. RESULTS: Circulating EVs were heterogeneous in morphology and size, but SLE-EVs reached larger diameters than Ctrl-EVs (p<0.0001). Small SLE-EVs and large SLE-EVs were increased compared with Ctrl-EV (p<0.0001 and p<0.05, respectively). Likewise, patients with SLE (LN or nLN) had higher concentrations of large EVs compared with controls (p<0.001 and p<0.0001, respectively). SLE-EVs showed a different EDS (p<0.001) and were less electronegative (p<0.0001) than Ctrl-EVs. EV-CD45+, EV-CD14+ and EV-IgM+ were more frequent in patients with SLE compared with controls (p<0.001, p<0.05 and p<0.001, respectively). The concentrations of large EVs and EV-IgM+ allowed better discrimination of patients from controls. CONCLUSIONS: Plasma-circulating EVs from patients with SLE with and without nephritis are increased in peripheral blood and have different physicochemical properties than controls. Characteristics of EVs such as larger size and the presence of IgM on the surface could help discriminate patients from controls.

Dengue and Zika virus differential infection of human megakaryoblast MEG-01 reveals unique cellular markers.

Platelet count is widely used for the diagnosis and follow-up of patients with dengue. Despite its close viral structural and symptomatic homology, ZIKV infection does not typically induce significant thrombocytopenia. To determine the effect of DENV-2 and ZIKV infection on human platelet precursors we utilized MEG-01 cell line to evaluate the viral infection, viability, innate gene expression and release of platelet-like particles (PLPs). DENV-2 induced a higher proportion of cell death at 48-72 h post-infection than ZIKV. The median range of intracellular NS1+/E+ cells was 11.2% (3.3%-25%) and 5% (3%-8.1%) for DENV-2 and ZIKV, respectively (p = 0.03). MEG-01 cells infected with DENV-2 quickly expressed higher levels of IFN-ß, indolamine 2,3-dioxygenase and CXCL10 mRNA compared to ZIKV infected cells and DENV-2 but not ZIKV infection reduced the number PLPs from stimulated MEG-01 cells. The results shed light into mechanisms including thrombocytopenia present in patients with DENV but absent in ZIKV infections.

Dengue Virus and Platelets: From the Biology to the Clinic.

Dengue is one of the most important vector-borne viral illnesses found in tropical and subtropical regions. Colombia has one of the highest rates of dengue cases in the Americas. Severe dengue virus (DENV) infection presents with capillary leakage, hemorrhage, and organ compromise, eventually leading to death. Over the years, there have been many efforts to develop a vaccine that guarantees protective immunity, but they have been partially successful, as such immunity would need to guarantee protection against four distinct viral serotypes. Absolute platelet count is a laboratory parameter used to monitor the clinical progression of DENV, as infection is often accompanied by thrombocytopenia. Although this finding is well described with respect to the natural history of the disease, there are various hypotheses as to the cause of this rapid decrease, and several in vivo and ex vivo models have been used to explain the effect of DENV infection on platelets and their precursors. DENV infects and activates platelets, facilitating their elimination through recognition by phagocytic cells and peripheral margination. However, infection also affects the precursors in the bone marrow by modulating megakaryopoiesis. The objective of this article is to explore various proposed mechanisms of DENV-induced thrombocytopenia to better understand the pathophysiology and clinical presentations of this highly relevant viral infection.

Papel de la interleuquina-17 en procesos inflamatorios y patologías pulmonares / Role of interleukin-17 in inflammatory processes and pulmonary pathologies

Resumen Introducción: Cuatro de las diez principales causas de muerte en el mundo corresponden a patologías pulmonares donde las infecciones respiratorias se ubican en tercer lugar y a su vez son uno de los principales motivos de consulta médica. Por otro lado, la interleuquina IL-17 parece tener un papel importante en la inmunopatogénesis de un gran número de enfermedades, pues se ha descrito que niveles elevados en sangre periférica u otros fluidos corporales se relacionan con metástasis e infecciones. Diferente a patologías cutáneas e intestinales, donde el papel de la IL-17 se conoce con mayor detalle, en procesos pulmonares su rol es aún controversial. Objetivo: Describir conocimientos actuales sobre la función de la IL-17 en procesos inflamatorios y patologías locales pulmonares. Metodología de búsqueda: Se realizó una búsqueda bibliográfica de artículos originales y revisiones de tema en los motores de búsqueda MEDLINE y Science Direct, de los cuales 50 cumplieron con los criterios de inclusión. Conclusiones: Se encontró que la respuesta de IL-17 parece estar relacionada con buen pronóstico en el caso de algunas neumonías bacterianas. Igualmente, el bloqueo de la vía de señalización de la IL-17 en neoplasias pulmonares podría ser beneficioso y se considera como un potencial blanco terapéutico en estas condiciones, por lo que los estudios en este tema continúan siendo fundamentales para conocer mejor el verdadero rol de esta proteína en diversas condiciones patológicas del pulmón. MÉD.UIS.2021;34(1): 55-62.

Abstract Introduction: Four out of ten major causes of death in the world are due to pulmonary pathologies where respiratory infections are in third place and in turn, are one of the main reasons for medical consultation. Interleukin (IL)-17 seems to have an important role in the immunopathogenesis of many diseases. Elevated levels of IL-17 in peripheral blood or other body fluids have been reported to be associated with metastases and infections. Likewise, the role that IL-17 has in the skin and intestinal pathology is clearly known, however; its role within pulmonary pathologies is controversial yet. Objective: To describe the current knowledge on the role of IL-17 in inflammatory processes and pulmonary pathologies. Search Methodology: A bibliographic search of original and review papers was carried out in the MEDLINE and Science Direct database, in which 50 articles matched the inclusion criteria. Conclusions: The response involving IL-17 in the lung seems to be related to a good prognosis in the case of some bacterial pneumonia. Blocking the IL-17 signaling pathway in lung cancer could be beneficial and is considered as a potential therapeutic target under these conditions, so studies on this subject must be continued to better understand the true role of this protein in every pathologic lung condition. MÉD.UIS.2021;34(1): 55-62.

Interleukin-6 as a Biomarker of Early-Onset Neonatal Sepsis.

OBJECTIVE: The aim of this study is to determine the utility of C reactive protein (CRP) and interleukin (IL)-6 in the diagnosis of neonatal sepsis (NS) in a neonatal intensive care unit (NICU) in the south of Colombia. STUDY DESIGN: A nonmatched case-control study was conducted. Convenience sampling was performed. Data were obtained from clinical records. IL-6 levels were determined using enzyme-linked immunosorbent assay. Receiver operator characteristic (ROC) curve analysis and Youden's index were used to determine the optimal cutoffs for CRP and IL-6 levels in diagnosing NS, early-onset NS (EONS), and late-onset NS (LONS). RESULTS: Data from 31 cases and 62 controls were included. History of chorioamnionitis (infinite odds ratio [OR] [3.07-infinity]), and the presence of meconium-stained amniotic fluid during birth (OR: 9.04 [1.35-112]) were identified as risk factors for NS. Differences in CRP (p < 0.0001) and IL-6 (p < 0.0485) levels were also found, more significantly for LONS and EONS patients, respectively. In the diagnosis of LONS using CRP levels, the area under the ROC curve (AUC) was 0.8371 (p < 0.0001). The optimal cutoff was 0.53 mg/dL. For EONS diagnosis using IL-6, the AUC was 0.6869 (p = 0.0315) and the optimal cutoff was 17.75 pg/mL. CONCLUSION: Differences between CRP and IL-6 levels were found between control and NS groups. Furthermore, CRP showed greater potential diagnostic utility in the LONS group, whereas IL-6 showed greater potential utility in the EONS group. KEY POINTS: · NS is a major morbimortality cause worldwide. · CRP and IL-6 levels may be useful NS biomarkers. · No biomarker alone is enough for the diagnosis of NS.