Neutrophil extracellular traps in autoimmune diseases / Trampas extracelulares de neutrófilos en enfermedades autoinmunes

ABSTRACT Neutrophils play an important role in immune defence against several pathogens. These cells actively participate in the innate immune response through different functions, such as chemotaxis, phagocytosis, oxidative burst and degranulation, which have been widely studied. However, in the last few years, a new function has been described; activated neutrophils are able to release web-like chromatin structures known as neutrophil extracellular traps (NETs). These structures formed by DNA, histones, and proteins, immobilize and kill microorganisms. Disruption in NET formation is associated with the pathophysiology of several disorders, including the autoimmune diseases. NETs are an important source of the autoantigens involved in the production of autoantibodies and maintenance of the inflammatory milieu. This review provides a summary of the contribution of NETs to the pathogenesis of anti-neutrophil cytoplasmic antibodies-associated vasculitis, systemic lupus erythematosus, and rheumatoid arthritis. The preliminary findings on NETs components in Sjögren.'s syndrome will also be described.

RESUMEN Los neutrófilos juegan un papel muy importante en la defensa inmune contra diferentes patógenos. Estas células participan activamente en la respuesta inmune innata a través de diferentes funciones como quimiotaxis, fagocitosis, estallido oxidativo y degranulación, las cuales han sido estudiadas ampliamente. Sin embargo, en los últimos años se ha descrito una nueva función; los neutrófilos activados son capaces de liberar redes de cromatina llamadas trampas extracelulares de neutrófilos (NETs). Estas estructuras están formadas por ADN, histonas y proteínas capaces de inmovilizar y matar microorganismos. Alteraciones en la formación de estas NETs están asociadas con la fisiopatología de varios trastornos, incluyendo las enfermedades autoinmunes (EAI). Las NETs son consideradas una fuente de autoantígenos que ayudan a la producción de autoanticuerpos y al mantenimiento de un ambiente inflamatorio. Esta revisión resume la contribución de las NETs a la patogénesis de vasculitis asociada a anticuerpos contra el citoplasma de los neutrófilos, lupus eritematoso sistémico y artritis reumatoide. Adicionalmente, se describirán los resultados preliminares de la detección de componentes de las NETs en pacientes con síndrome de Sjögren.

Autoimmune (auto-inflammatory) syndrome induced by adjuvants (ASIA)--animal models as a proof of concept.

ASIA syndrome, "Autoimmune (Auto-inflammatory) Syndromes Induced by Adjuvants" includes at least four conditions which share a similar complex of signs and symptoms and have been defined by hyperactive immune responses: siliconosis, macrophagic myofasciitis syndrome, Gulf war syndrome and post-vaccination phenomena. Exposure to adjuvants has been documented in these four medical conditions, suggesting that the common denominator to these syndromes is a trigger entailing adjuvant activity. An important role of animal models in proving the ASIA concept has been established. Experimentally animal models of autoimmune diseases induced by adjuvants are currently widely used to understand the mechanisms and etiology and pathogenesis of these diseases and might thus promote the development of new diagnostic, predictive and therapeutic methods. In the current review we wish to unveil the variety of ASIA animal models associated with systemic and organ specific autoimmune diseases induced by adjuvants. We included in this review animal models for rheumatoid arthritis-like disease, for systemic lupus erythematosus-like disease, autoimmune thyroid disease-like disease, antiphospholipid syndrome, myocarditis and others. All these models support the concept of ASIA, as the Autoimmune (Auto-inflammatory) Syndrome Induced by Adjuvants.

Passive transfer of narcolepsy: anti-TRIB2 autoantibody positive patient IgG causes hypothalamic orexin neuron loss and sleep attacks in mice.

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and cataplexy (a sudden weakening of posture muscle tone usually triggered by emotion) caused by the loss of orexin neurons in the hypothalamus. Autoimmune mechanisms are implicated in narcolepsy by increased frequency of specific HLA alleles and the presence of specific autoantibody (anti-Tribbles homolog 2 (TRIB2) antibodies) in the sera of patients with narcolepsy. Presently, we passively transferred narcolepsy to naïve mice by injecting intra-cerebra-ventricularly (ICV) pooled IgG positive for anti-TRIB2 antibodies. Narcolepsy-IgG-injected mice had a loss of the NeuN (neuronal marker), synaptophysin (synaptic marker) and orexin-positive neurons in the lateral hypothalamus area in narcolepsy compared to control-IgG-injected mice and these changes were associated with narcolepsy-like immobility attacks at four weeks post injection and with hyperactivity and long term memory deficits in the staircase and novel object recognition tests. Similar behavioral and cognitive deficits are observed in narcoleptic patients. This is the first report of passive transfer of experimental narcolepsy to naïve mice induced by autoantibodies and supports the autoimmune pathogenesis in narcolepsy.

Similar biotherapeutic products: overview and reflections.

Biotherapeutic products (BPs) have revolutionized medicine, changing the way we treat several pathologies such as autoimmune diseases and cancer, among others. Herein, we present an overview of similar BPs (SBPs), also called biosimilars, including the manufacturing process and regulatory aspects involved. The objective of developing an SBP is to manufacture a molecule that is highly similar to a reference BP by conducting a comparability exercise (CE) that can demonstrate similar safety and efficacy. This CE consists of quality, as well as nonclinical and clinical evaluation. A case-by-case analysis approach guided by scientific and objective standards must be the foundation for the SBP approval process. The establishment of a balance between a comprehensive CE for SBPs and their reference BPs, and the design of costeffective strategies to provide better access to BPs, should be the key goal for national regulatory authorities.

The impact of disease activity on the quality of life, mental health status, and family dysfunction in colombian patients with rheumatoid arthritis.

This study investigated the relationship between activity of disease, mental health status, quality of life, and family dysfunction in northwestern Colombian patients with rheumatoid arthritis (RA). Seventy-nine patients completed a 2-phase study that included physical examination (objective measurement of disease activity according to adapted American College of Rheumatology criteria) and a pretested questionnaire that sought information on helplessness, disability, depression, anxiety, quality of life, arthritis self-efficacy for pain, and other symptoms, as well as family dysfunction and socioeconomic status. Nineteen patients (24%) had active RA, 48 (61%) had moderately active RA, and 12 (15%) were in remission. Symptoms of depression, helplessness, disability, pain, anxiety, lower quality of life, and self-efficacy were associated with RA activity regardless of age, sex, and duration of the disease. Symptoms of depression were directly correlated with anxiety, helplessness, pain, and disability and inversely correlated with quality of life and self-efficacy. Although family dysfunction was present in 39% of patients, no associations between family dysfunction, activity of RA, mental health variables, socioeconomical status or quality of life were observed. These results indicate that RA activity significantly influences mental health status and quality of life in this population. Accordingly, a holistic conception of therapy should guide the treatment of patients with RA.