RESUMO
Intravenous immunoglobulin (IVIg), a preparation of polyclonal serum IgG pooled from numerous blood donors, has been used for nearly three decades and is proving to be an efficient treatment for many autoimmune blistering diseases, including pemphigus vulgaris (PV). Despite its widespread use and therapeutic success, its mechanisms of action are not completely understood. Some of its anti-inflammatory and immunomodulatory actions have been studied. In this study, the authors present a twenty-year follow-up of 21 patients with clinical and immunopathological confirmed PV, treated with IVIg as monotherapy, according to an established published protocol. IVIg therapy produced long-term sustained, clinical, serological, and immunopathological remission. For 20 y, these patients received no drugs and experienced no disease. This observation suggests that there was the establishment of immune balance or restoration of immune regulation in these PV patients. Twelve (57%) patients experienced no relapse during follow-up. Six (29%) patients experienced a relapse due to acute stress or post-coronavirus infection and/or vaccination. Reinstitution of IVIg resulted in prompt sustained recovery. Three (14.2%) patients, in clinical and serological remission, died due to unrelated causes. No severe adverse effects from IVIg were documented in all 21 patients. The simultaneous or sequential anti-inflammatory and immunomodulatory effects of IVIg may have influenced the long-term clinical remission observed. This study provides a human prototype to examine the pathophysiology of autoimmunity and a model to study immune regulation and mechanisms that can facilitate restoring immune tolerance.
Assuntos
Doenças Autoimunes , Pênfigo , Humanos , Imunoglobulinas Intravenosas , Tolerância Imunológica , Anti-InflamatóriosRESUMO
Intravenous immunoglobulin (IVIG) is the mainstay of therapy for humoral immune deficiencies and numerous inflammatory disorders. Although the use of IVIG may be supplanted by several targeted therapies to cytokines, the ability of polyclonal normal IgG to act as an effector molecule as well as a regulatory molecule is a clear example of the polyfunctionality of IVIG. This article will address the mechanism of action of IVIG in a number of important conditions that are otherwise resistant to treatment. In this commentary, we will highlight mechanistic studies that shed light on the action of IVIG. This will be approached by identifying effects that are both common and disease-specific, targeting actions that have been demonstrated on cells and processes that represent both innate and adaptive immune responses.
Assuntos
Doenças Autoimunes , Síndromes de Imunodeficiência , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Citocinas , Imunidade HumoralRESUMO
Intravascular hemolysis occurs in diverse pathological conditions. Extracellular hemoglobin and heme have strong pro-oxidative and pro-inflammatory potentials that can contribute to the pathology of hemolytic diseases. However, many of the effects of extracellular hemoglobin and heme in hemolytic diseases are still not well understood. Here we demonstrate that oxidized hemoglobin (methemoglobin) can modify the antigen-binding characteristics of human immunoglobulins. Thus, incubation of polyclonal or some monoclonal human IgG in the presence of methemoglobin results in an appearance of binding reactivities towards distinct unrelated self-proteins, including the protein constituent of hemoglobin i.e., globin. We demonstrate that a transfer of heme from methemoglobin to IgG is indispensable for this acquisition of antibody polyreactivity. Our data also show that only oxidized form of hemoglobin have the capacity to induce polyreactivity of antibodies. Site-directed mutagenesis of a heme-sensitive human monoclonal IgG1 reveals details about the mechanism of methemoglobin-induced antigen-binding polyreactivity. Further here we assess the kinetics and thermodynamics of interaction of a heme-induced polyreactive human antibody with hemoglobin and myoglobin. Taken together presented data contribute to a better understanding of the functions of extracellular hemoglobin in the context of hemolytic diseases.
Assuntos
Heme , Metemoglobina , Humanos , Heme/metabolismo , Metemoglobina/metabolismo , Hemoglobinas/metabolismo , Imunoglobulina G , Anticorpos Monoclonais , HemóliseRESUMO
Intravenous immunoglobulin (IVIg) is used as treatment for several autoimmune and inflammatory conditions, but its specific mechanisms are not fully understood. Herein, we aimed to evaluate, using systems biology and artificial intelligence techniques, the differences in the pathophysiological pathways of autoimmune and inflammatory conditions that show diverse responses to IVIg treatment. We also intended to determine the targets of IVIg involved in the best treatment response of the evaluated diseases. Our selection and classification of diseases was based on a previously published systematic review, and we performed the disease characterization through manual curation of the literature. Furthermore, we undertook the mechanistic evaluation with artificial neural networks and pathway enrichment analyses. A set of 26 diseases was selected, classified, and compared. Our results indicated that diseases clearly benefiting from IVIg treatment were mainly characterized by deregulated processes in B cells and the complement system. Indeed, our results show that proteins related to B-cell and complement system pathways, which are targeted by IVIg, are involved in the clinical response. In addition, targets related to other immune processes may also play an important role in the IVIg response, supporting its wide range of actions through several mechanisms. Although B-cell responses and complement system have a key role in diseases benefiting from IVIg, protein targets involved in such processes are not necessarily the same in those diseases. Therefore, IVIg appeared to have a pleiotropic effect that may involve the collaborative participation of several proteins. This broad spectrum of targets and 'non-specificity' of IVIg could be key to its efficacy in very different diseases.
Assuntos
Doenças Autoimunes , Imunoglobulinas Intravenosas , Inteligência Artificial , Doenças Autoimunes/tratamento farmacológico , Proteínas do Sistema Complemento , Humanos , Biologia de SistemasRESUMO
In 2016, the European Hematology Association (EHA) published the EHA Roadmap for European Hematology Research 1 aiming to highlight achievements in the diagnostics and treatment of blood disorders, and to better inform European policy makers and other stakeholders about the urgent clinical and scientific needs and priorities in the field of hematology. Each section was coordinated by 1-2 section editors who were leading international experts in the field. In the 5 years that have followed, advances in the field of hematology have been plentiful. As such, EHA is pleased to present an updated Research Roadmap, now including eleven sections, each of which will be published separately. The updated EHA Research Roadmap identifies the most urgent priorities in hematology research and clinical science, therefore supporting a more informed, focused, and ideally a more funded future for European hematology research. The 11 EHA Research Roadmap sections include Normal Hematopoiesis; Malignant Lymphoid Diseases; Malignant Myeloid Diseases; Anemias and Related Diseases; Platelet Disorders; Blood Coagulation and Hemostatic Disorders; Transfusion Medicine; Infections in Hematology; Hematopoietic Stem Cell Transplantation; CAR-T and Other Cell-based Immune Therapies; and Gene Therapy.
RESUMO
Intravenous immunoglobulin (IVIG) is used to treat several autoimmune and inflammatory diseases, but some patients are refractory to IVIG and require alternative treatments. Identifying a biomarker that could segregate IVIG responders from non-responders has been a subject of intense research. Unfortunately, previous transcriptomic studies aimed at addressing IVIG resistance have failed to predict a biomarker that could identify IVIG-non-responders. Therefore, we used a novel data mining technique on the publicly available transcriptomic data of Kawasaki disease (KD) patients treated with IVIG to identify potential biomarkers of IVIG response. By studying the boolean patterns hidden in the expression profiles of KD patients undergoing IVIG therapy, we have identified new metabolic pathways implicated in IVIG resistance in KD. These pathways could be used as biomarkers to segregate IVIG non-responders from responders prior to IVIG infusion. Also, boolean analysis of the transcriptomic data could be further extended to identify a universal biomarker that might predict IVIG response in other autoimmune diseases.
Assuntos
Imunoglobulinas Intravenosas , Síndrome de Linfonodos Mucocutâneos , Biomarcadores , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Lactente , Síndrome de Linfonodos Mucocutâneos/diagnóstico , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , Síndrome de Linfonodos Mucocutâneos/genética , Estudos Retrospectivos , TranscriptomaAssuntos
Púrpura Trombocitopênica Idiopática , Trombocitopenia , Trombose , Vacinas , Humanos , Imunoglobulinas Intravenosas/efeitos adversos , Púrpura Trombocitopênica Idiopática/induzido quimicamente , Púrpura Trombocitopênica Idiopática/diagnóstico , Púrpura Trombocitopênica Idiopática/tratamento farmacológicoRESUMO
In this report we provide a hypothesis of how intravenous immunoglobulin (IvIg) (pooled therapeutic normal IgG) mitigates the severe disease after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The disease is caused by an overreaction of the innate immune system producing a cytokine storm and inflicting multiple organ damage. Our interpretation of IvIg therapy hinges on a recent analysis of the immune dysregulation in Covid-19 infection. Previous infections with common cold coronavirus induce suppressor memory B cells that inhibit an immune response to Covid-19. The repertoire of natural antibodies (IvIg) contains suppressing antibodies in a symmetrically balanced network structure. When this repertoire interacts with the imbalanced network in the infected patient, it can neutralize the suppression of an antibody response against Covid-19. The described scenario for IvIg in Covid-19 infection may also apply in the therapy of autoimmune diseases.
Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19/imunologia , Imunoglobulinas Intravenosas/uso terapêutico , Modelos Imunológicos , Imunidade Adaptativa , Síndrome da Liberação de Citocina/imunologia , Síndrome da Liberação de Citocina/prevenção & controle , Humanos , Receptores de Antígenos de Linfócitos B/imunologiaRESUMO
Intravenous immunoglobulin (IVIG), a pooled normal IgG from several thousand healthy donors and one of the commonly used immunotherapeutic molecules for the management of autoimmune and inflammatory diseases, has been explored for the treatment of coronavirus disease-19 (COVID-19). Although placebo-controlled, double-blind randomised clinical trials are lacking, current data from either retrospective, case series or open-label randomised controlled trials provide an indicator that IVIG immunotherapy could benefit severe and critically ill COVID-19 patients. See alsoShao et al.
RESUMO
Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has infected millions, with more than 275,000 fatal cases as of May 8, 2020. Currently, there are no specific COVID-19 therapies. Most patients depend on mechanical ventilation. Current COVID-19 data clearly highlight that cytokine storm and activated immune cell migration to the lungs characterize the early immune response to COVID-19 that causes severe lung damage and development of acute respiratory distress syndrome. In view of uncertainty associated with immunosuppressive treatments, such as corticosteroids and their possible secondary effects, including risks of secondary infections, we suggest immunotherapies as an adjunct therapy in severe COVID-19 cases. Such immunotherapies based on inflammatory cytokine neutralization, immunomodulation, and passive viral neutralization not only reduce inflammation, inflammation-associated lung damage, or viral load but could also prevent intensive care unit hospitalization and dependency on mechanical ventilation, both of which are limited resources.
Assuntos
COVID-19/terapia , Imunoterapia , Anticorpos Monoclonais/uso terapêutico , Antivirais/uso terapêutico , COVID-19/imunologia , Terapia Combinada , Síndrome da Liberação de Citocina/imunologia , Síndrome da Liberação de Citocina/terapia , Citocinas/imunologia , Humanos , Imunização Passiva , Imunoglobulinas Intravenosas/uso terapêutico , Inflamação , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/transplante , Síndrome do Desconforto Respiratório/imunologia , Síndrome do Desconforto Respiratório/terapia , SARS-CoV-2 , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/transplanteRESUMO
Therapeutic normal IgG intravenous immunoglobulin (IVIG) is a well-established first-line immunotherapy for many autoimmune and inflammatory diseases. Though several mechanisms have been proposed for the anti-inflammatory actions of IVIG, associated signaling pathways are not well studied. As ß-catenin, the central component of the canonical Wnt pathway, plays an important role in imparting tolerogenic properties to dendritic cells (DCs) and in reducing inflammation, we explored whether IVIG induces the ß-catenin pathway to exert anti-inflammatory effects. We show that IVIG in an IgG-sialylation independent manner activates ß-catenin in human DCs along with upregulation of Wnt5a secretion. Mechanistically, ß-catenin activation by IVIG requires intact IgG and LRP5/6 co-receptors, but FcγRIIA and Syk are not implicated. Despite induction of ß-catenin, this pathway is dispensable for anti-inflammatory actions of IVIG in vitro and for mediating the protection against experimental autoimmune encephalomyelitis in vivo in mice, and reciprocal regulation of effector Th17/Th1 and regulatory T cells.
Assuntos
Células Dendríticas/efeitos dos fármacos , Imunoglobulinas Intravenosas/farmacologia , beta Catenina/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Feminino , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Células Th17/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/efeitos dos fármacosRESUMO
Basophils are rare granulocytes and dysregulated functions of these cells are associated with several atopic and non-atopic allergic diseases of skin, respiratory system and gastrointestinal tract. Both cytokines and immunoglobulin E (IgE) are implicated in mediating the basophil activation and pathogenesis of these disorders. Several reports have shown that healthy individuals, and patients with allergic disorders display IgG autoantibodies to IgE and hence functional characterization of these anti-IgE IgG autoantibodies is critical. In general, anti-IgE IgG autoantibodies modulate basophil activation irrespective of allergen specificity by interacting with constant domains of IgE. Therefore, an ideal solution to prove the functions of such anti-IgE IgG autoantibodies would be to completely eliminate type I high affinity immunoglobulin E receptor (FcÉRI)-bound IgE from the surface of basophils and to demonstrate in an unequivocal manner the role of anti-IgE IgG autoantibodies. In line with previous reports, our data show that FcÉRI on peripheral blood basophils are almost saturated with IgE. Further, acetic acid buffer (pH 4) efficiently removes these FcÉRI-bound IgE. Although immediately following acetic acid-elution of IgE had no repercussion on the viability of basophils, following 24 hours culture with interleukin-3 (IL-3), the viability and yield of basophils were drastically reduced in acid-treated cells and had repercussion on the induction of activation markers. Lactic acid treatment on the other hand though had no adverse effects on the viability of basophils and IL-3-induced activation, it removed only a small fraction of the cell surface bound IgE. Thus, our results show that acid buffers could be used for the elution of FcÉRI-bound IgE on the basophil surface for the biochemical characterization of IgE antibodies or for the immediate use of basophils to determine their sensitivity to undergo degranulation by specific allergens. However, these methods are not utile for the functional assays of basophils that require longer duration of culture and entire removal of surface IgE to validate the role of anti-IgE IgG autoantibodies that interact with FcÉRI-bound IgE irrespective of allergen specificity.
Assuntos
Ácido Acético , Basófilos , Bioensaio , Imunoglobulina E , Receptores de IgE/imunologia , Ácido Acético/química , Ácido Acético/farmacologia , Basófilos/química , Basófilos/imunologia , Técnicas de Cultura de Células , Humanos , Imunoglobulina E/química , Imunoglobulina E/imunologiaRESUMO
Autophagy plays an important role in the regulation of autoimmune and autoinflammatory responses of the immune cells. Defective autophagy process is associated with various autoimmune and inflammatory diseases. Moreover, in many of these diseases, the therapeutic use of normal immunoglobulin G or intravenous immunoglobulin (IVIG), a pooled normal IgG preparation, is well documented. Therefore, we explored if IVIG immunotherapy exerts therapeutic benefits via induction of autophagy in the immune cells. Here we show that IVIG induces autophagy in peripheral blood mononuclear cells (PBMCs). Further dissection of this process revealed that IVIG-induced autophagy is restricted to inflammatory cells like monocytes, dendritic cells, and M1 macrophages but not in cells associated with Th2 immune response like M2 macrophages. IVIG induces autophagy by activating AMP-dependent protein kinase, beclin-1, class III phosphoinositide 3-kinase and p38 mitogen-activated protein kinase and by inhibiting mammalian target of rapamycin. Mechanistically, IVIG-induced autophagy is F(ab')2-dependent but sialylation independent, and requires endocytosis of IgG by innate cells. Inhibition of autophagy compromised the ability of IVIG to suppress the inflammatory cytokines in innate immune cells. Moreover, IVIG therapy in inflammatory myopathies such as dermatomyositis, antisynthetase syndrome and immune-mediated necrotizing myopathy induced autophagy in PBMCs and reduced inflammatory cytokines in the circulation, thus validating the translational importance of these results. Our data provide insight on how circulating normal immunoglobulins maintain immune homeostasis and explain in part the mechanism by which IVIG therapy benefits patients with autoimmune and inflammatory diseases.
Assuntos
Anti-Inflamatórios/farmacologia , Autofagia/efeitos dos fármacos , Imunoglobulinas Intravenosas/farmacologia , Leucócitos Mononucleares/metabolismo , Adenilato Quinase/metabolismo , Proteína Beclina-1/metabolismo , Linhagem Celular , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Células Dendríticas/ultraestrutura , Endocitose/efeitos dos fármacos , Humanos , Imunidade Inata/efeitos dos fármacos , Fragmentos Fab das Imunoglobulinas/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Organelas/efeitos dos fármacos , Organelas/metabolismo , Organelas/ultraestrutura , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Doadores de Tecidos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Intravenous immunoglobulin (IVIG) is one of the widely used immunotherapeutic molecules in the therapy of autoimmune and inflammatory diseases. Previous reports demonstrate that one of the anti-inflammatory actions of IVIG implicates suppression of macrophage activation and release of their inflammatory mediators. However, macrophages are highly plastic and depending on the microenvironmental signals, macrophages can be polarized into pro-inflammatory classic (M1) or anti-inflammatory alternative (M2) type. This plasticity of macrophages raised additional questions on the role of IVIG towards macrophage polarization. In the present report, we show that IVIG affects the polarization of both classically and alternatively activated macrophages and this process is F(ab')2-independent. Our data thus indicate the lack of reciprocal regulation of inflammatory and non-inflammatory macrophages by IVIG.
Assuntos
Imunoglobulinas Intravenosas , Macrófagos , Anti-Inflamatórios , Ativação de MacrófagosRESUMO
The innate immune response provides a first line of defense against common microorganisms and, for more complex and/or recurring situations where pathogens must be eliminated, an adaptive immune response has emerged and evolved to provide better protection against subsequent infections. However, such dichotomy has to be reevaluated because innate B cells (e.g., B1 and marginal zone B cells) and the newly described innate lymphoid cells (iLC) have been found to exhibit innate-like properties, such as antigen internalization, regulatory B cell functions, and helper T cell activities. In addition, the production and function of natural antibodies (nAbs) by innate B cells and their capacity to activate the classical complement pathway constitute additional important mechanisms at the junction of innate and adaptive immunity as well as the recent integration of platelets into the innate immune spectrum. There is no doubt that these mechanisms present an advantage in immunity and homeostasis particularly during the first years of life, but arguments are arising to consider that these precursors may have detrimental effects in a variety of autoimmune/inflammatory diseases, allergies and cancers, as well as in response to immunotherapy. Accordingly, and as presented in this special issue of Clinical Reviews in Allergy and Immunology, a better comprehension of the key molecular and cellular actors implicated at the crossroads of the innate and adaptive immune response represents a new challenge in our understanding of the immunological and immunopathological responses.
Assuntos
Imunidade Adaptativa , Sistema Imunitário/fisiologia , Imunidade Inata , Imunidade Adaptativa/efeitos dos fármacos , Animais , Subpopulações de Linfócitos B/efeitos dos fármacos , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Biomarcadores , Plasticidade Celular/imunologia , Epigênese Genética/efeitos dos fármacos , Humanos , Sistema Imunitário/efeitos dos fármacos , Imunidade Humoral , Imunidade Inata/efeitos dos fármacos , Inibidores de Janus Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Receptores Toll-Like/metabolismoRESUMO
Natural antibodies (nAbs) are most commonly defined as immunoglobulins present in the absence of pathological conditions or deliberate immunizations. Occurrence of nAbs in germ- and antigen-free mice suggest that their production is driven, at least in part, by self-antigens. Accordingly, nAbs are constituted of natural autoantibodies (nAAbs), and can belong to the IgM, IgG, or IgA subclasses. These nAbs provide immediate protection against infection while the adaptive arm of the immune system mounts a specific and long-term response. Beyond immediate protection from infection, nAbs have been shown to play various functional roles in the immune system, which include clearance of apoptotic debris, suppression of autoimmune and inflammatory responses, regulation of B cell responses, selection of the B cell repertoires, and regulation of B cell development. These various functions of nAbs are afforded by their reactivity, which is broad, cross-reactive, and shown to recognize evolutionarily fixed epitopes shared between foreign and self-antigens. Furthermore, nAbs have unique characteristics that also contribute to their functional roles and set them apart from antigen-specific antibodies. In further support for the role of nAbs in the protection against infections and in the maintenance of immune homeostasis, the therapeutic preparation of polyclonal immunoglobulins, intravenous immunoglobulin (IVIG), rich in nAbs is commonly used in the replacement therapy of primary and secondary immunodeficiencies and in the immunotherapy of a large number of autoimmune and inflammatory diseases. Here, we review several topics on nAbs features and functions, and therapeutic applications in human diseases.
Assuntos
Anticorpos/imunologia , Homeostase/imunologia , Imunidade , Animais , Anticorpos/sangue , Formação de Anticorpos/imunologia , Resistência à Doença/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Tolerância Imunológica , Imunidade Inata , Isotipos de Imunoglobulinas/sangue , Isotipos de Imunoglobulinas/imunologia , Imunomodulação , Especificidade de Órgãos/imunologiaRESUMO
High-mobility group box 1 (HMGB1) concentration in serum or plasma has been proposed as an important biological marker in various inflammation-related pathologies. We previously showed that low titer autoantibodies against HMGB1 could emerge during the course of sepsis. Importantly their presence was positively related with patients' survival. In this study, we focused on plasma samples from 2 patients who survived sepsis and exhibited high titer antibodies to HMGB1. These antibodies were proved to be specific for HMGB1 since they did not bind to HMGB2 or to human serum albumin. Following IgG purification, it has shown that both patients secreted HMGB1-hydrolyzing autoantibodies in vitro. These findings suggested that proteolytic antibodies directed against HMGB1 can be produced in patients surviving septic shock.
Assuntos
Autoanticorpos/imunologia , Proteína HMGB1/imunologia , Choque Séptico/imunologia , Autoanticorpos/sangue , Proteína HMGB2/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Proteólise , Albumina Sérica Humana/imunologia , Choque Séptico/mortalidade , Choque Séptico/patologiaRESUMO
The authors wish to make the following corrections to this paper [...].