Susceptibilidad genética y enfermedad autoinmune reumática: Revisión narrativa / Genetic susceptibility and autoimmune rheumatic disease: Narrative review

La autoinmunidad es la consecuencia de la pérdida de control y regulación de la respuesta inmune. Se re-porta que ocurre entre 5 y 9% de patologías a nivel mundial. A las enfermedades con esta anomalía se les denomina autoinmunes y se clasifican de acuerdo con el órgano o sistema afectado. Las reumáticas involucran al tejido conectivo y las articulaciones. Los factores asociados a su aparición incluyen: edad, género, medioam-biente y genéticos. La susceptibilidad genética indica la presencia de uno o varios genes asociados al desarrollo de determinada enfermedad, cuya expresión podría ser el producto de la migración, selección, recombinación y adaptación de genes entre las poblaciones, lo que explica la variación fenotípica y la expresión clínica resultan-te. Los estudios de asociación del genoma completo (GWAS por sus siglas en inglés) han permitido identificar múltiples genes involucrados con enfermedades reumáticas, destacan el lupus eritematoso sistémico y artritis reumatoide, asociadas con más de 60 alelos, y otras como la espondilitis anquilosante, en donde la asociación ha sido primordialmente con un gen y sus polimorfismos. Esta revisión tiene como objetivo informar el estado de la susceptibilidad determinada genéticamente para estas enfermedades y el impacto que tiene sobre la expresión clínica. Se realizó una búsqueda en PubMed y la base de datos de la biblioteca Cochrane, se incluyeron artículos relacionados con las palabras clave propuestas desde el 2000. La revisión identifica genes y la asociación con estas enfermedades, expone la diversidad existente y justifica continuar la búsqueda de genes en todas las poblaciones.

Autoimmunity is the consequence of the loss of control and regulation of the immune response. It is reported that between 5 and 9% of pathologies occur worldwide. Diseases with this abnormality are called autoimmune and are classified according to the organ or system affected. Rheumatic diseases involve connective tissue and joints. Factors associated with its appearance include age, gender, environment, and genetics. Genetic suscepti-bility indicates the presence of one or more genes associated with the development of a certain disease, whose expression could be the product of migration, selection, recombination and adaptation of genes between popu-lations, which explains the phenotypic variation and the resulting clinical expression. Genome wide association studies (GWAS) have allowed the identification of multiple genes involved with rheumatic diseases, including systemic lupus erythematosus and rheumatoid arthritis, associated with more than 60 alleles, and others such as ankylosing spondylitis, where the association has been primarily with a gene and its polymorphisms. This review aims to report the status of genetically determined susceptibility to these diseases and the impact it has on clinical expression. A search was carried out in PubMed and the Cochrane library database, articles related to the proposed keywords from the year 2000 were included. The review identifies genes and the association with these diseases, exposes the existing diversity and justifies continuing the search for genes in all populations.

Evaluation of the structure, autoimmunity, and functions of the thyroid gland in familial Mediterranean fever patients

ABSTRACT Objective Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder that is frequently seen in the eastern Mediterranean region. The thyroid gland can be affected in FMF patients through autoimmunity or amyloidosis. Here, we aimed to evaluate the structure and functions of the thyroid gland in addition to possible autoimmunity in FMF patients. Subjects and methods The study was conducted by the Endocrinology and Metabolism and Internal Medicine Departments. Thirty FMF patients and 30 age and gender-matched healthy controls were enrolled in the study. Free thyroxin (fT4), free triiodothyronine (fT3), thyroid-stimulating hormone (TSH), and anti-thyroid peroxidase (anti-TPO) autoantibodies were investigated. Detailed thyroid grayscale and Doppler Ultrasonography examinations and shear-wave elastosonography (SWE) were performed in the patient and control groups. Results Anti-TPO was detected in 24% (n = 7) of the patients. On the grayscale US, mean thyroid volumes were similar between the FMF and the control groups (p > 0.05). By Doppler US, thyroid vascularity observed was detected in 10.3% (n = 3) of the patients. SWE revealed that the mean velocity value of right vs. left lobe in the patient group was 1.77 ± 0.45 m/s and 1.95 ± 0.51 m/s, respectively. Compared to the control group, the mean velocity values were significantly higher in the right (p = 0.004) and left (p = 0.01) lobes of the patient group. The mean stiffness value in the patient group was also significantly higher in the right and left lobes [10.13 ± 5.65 kPa (p = 0.005) and 12.24 ± 6.17 kPa (p = 0.02), respectively]. Conclusion Recognizing the complications of FMF early in the course of the disease is as important as the early diagnosis of the disorder. Based on this, thyroid functions and changes in its structure should be evaluated carefully for early diagnosis of a possible coexisting thyroid disorder. Arch Endocrinol Metab. 2020;64(1):66-70

Expression of miR-155, miR-146a, and miR-326 in T1D patients from Chile: relationship with autoimmunity and inflammatory markers

ABSTRACT Objective The aim of this research was to analyze the expression profile of miR-155, miR-146a, and miR-326 in peripheral blood mononuclear cells (PBMC) of 47 patients with type 1 diabetes mellitus (T1D) and 39 control subjects, as well as the possible association with autoimmune or inflammatory markers. Subjects and methods Expression profile of miRs by means of qPCR using TaqMan probes. Autoantibodies and inflammatory markers by ELISA. Statistical analysis using bivariate correlation. Results The analysis of the results shows an increase in the expression of miR-155 in T1D patients in basal conditions compared to the controls (p < 0.001) and a decreased expression level of miR-326 (p < 0.01) and miR-146a (p < 0.05) compared T1D patients to the controls. miR-155 was the only miRs associated with autoinmmunity (ZnT8) and inflammatory status (vCAM). Conclusion Our data show a possible role of miR-155 related to autoimmunity and inflammation in Chilean patients with T1D.

A importância de reconhecer a síndrome antifosfolípide na medicina vascular / The importance of recognizing antiphospholipid syndrome in vascular medicine

A síndrome antifosfolipíde (SAF) é uma doença autoimune sistêmica caracterizada por trombose arterial ou venosa recorrente e/ou morbidade gestacional e pela presença dos anticorpos antifosfolipídeos, podendo apresentar outras manifestações vasculares, como microangiopatia, arteriopatia crônica e SAF catastrófica. Determinados testes laboratoriais para a síndrome (por exemplo, o anticoagulante lúpico) podem sofrer interferência do uso de medicações anticoagulantes, dificultando o diagnóstico. A fisiopatologia da SAF é complexa, sendo enumerados no texto diversos mecanismos patogênicos relacionados à coagulação, ao endotélio e às plaquetas. Por fim, discutimos o tratamento da SAF de acordo com a presença e o tipo de manifestações clínicas, o uso dos anticoagulantes orais diretos e o manejo perioperatório de pacientes com SAF

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by recurrent arterial or venous thrombosis and/or gestational morbidity and by the presence of antiphospholipid antibodies. It can also cause other vascular manifestations such as microangiopathy, chronic arteriopathy and catastrophic APS (CAPS). Certain laboratory tests for the syndrome (for example, the lupus anticoagulant test) can be affected by the use of anticoagulant agents, making diagnosis more difficult. The pathophysiology of APS is complex, and several mechanisms of pathogenesis related to coagulation, endothelium, and platelets are discussed in this article. We conclude by discussing treatment of APS according to the presence and type of clinical manifestations, use of direct oral anticoagulants (DOAs), and perioperative management of patients with APS

Follicular helper T cell in immunity and autoimmunity

The traditional concept that effector T helper (Th) responses are mediated by Th1/Th2 cell subtypes has been broadened by the recent demonstration of two new effector T helper cells, the IL-17 producing cells (Th17) and the follicular helper T cells (Tfh). These new subsets have many features in common, such as the ability to produce IL-21 and to express the IL-23 receptor (IL23R), the inducible co-stimulatory molecule ICOS, and the transcription factor c-Maf, all of them essential for expansion and establishment of the final pool of both subsets. Tfh cells differ from Th17 by their ability to home to B cell areas in secondary lymphoid tissue through interactions mediated by the chemokine receptor CXCR5 and its ligand CXCL13. These CXCR5+ CD4+ T cells are considered an effector T cell type specialized in B cell help, with a transcriptional profile distinct from Th1 and Th2 cells. The role of Tfh cells and its primary product, IL-21, on B-cell activation and differentiation is essential for humoral immunity against infectious agents. However, when deregulated, Tfh cells could represent an important mechanism contributing to exacerbated humoral response and autoantibody production in autoimmune diseases. This review highlights the importance of Tfh cells by focusing on their biology and differentiation processes in the context of normal immune response to infectious microorganisms and their role in the pathogenesis of autoimmune diseases.

Acesso a informações sobre como evitar problemas bucais entre escolares da Rede Pública de Ensino / Access to information about how to prevent oral problems among school children in the public school network

O presente estudo propõe-se a identificar a prevalência do acesso a informações sobre como evitar problemas bucais entre escolares da rede pública de ensino, assim como os fatores associados a este acesso. Trata-se de um estudo transversal e analítico conduzido entre escolares de 12 anos de idade de um município brasileiro de grande porte populacional. Os exames foram realizados por 24 cirurgiões-dentistas treinados e calibrados com auxilio de 24 anotadores. A coleta de dados ocorreu em 36 escolas sorteadas das 89 escolas públicas do município. Foram conduzidas análises descritivas, univariadas e múltiplas. Dos 2510 escolares incluídos no estudo, 2211 relataram já ter recebido informações sobre como evitar problemas bucais. O acesso a tais informações foi maior entre os que utilizaram serviços odontológicos privado/convênio; e menor entre aqueles que utilizaram o serviço para tratamento, os que avaliaram o serviço como regular ou ruim/péssimo, os que utilizam como meio de higiene bucal somente escova dente/escova dente e higienização a língua e os que relataram não estarem satisfeitos com a aparência de seus dentes. Conclui-se que a maioria dos escolares teve acesso a informações sobre como evitar problemas bucais, o qual esteve associado a características dos serviços de saúde, comportamentos e desfechos de saúde.

The scope of this study is to identify the prevalence of access to information about how to prevent oral problems among schoolchildren in the public school network, as well as the factors associated with such access. This is a cross-sectional and analytical study conducted among 12-year-old schoolchildren in a Brazilian municipality with a large population. The examinations were performed by 24 trained dentists and calibrated with the aid of 24 recorders. Data collection occurred in 36 public schools selected from the 89 public schools of the city. Descriptive, univariate and multiple analyses were conducted. Of the 2510 schoolchildren included in the study, 2211 reported having received information about how to prevent oral problems. Access to such information was greater among those who used private dental services; and lower among those who used the service for treatment, who evaluated the service as regular or bad/awful. The latter use toothbrush only or toothbrush and tongue scrubbing as a means of oral hygiene and who reported not being satisfied with the appearance of their teeth. The conclusion drawn is that the majority of schoolchildren had access to information about how to prevent oral problems, though access was associated with the characteristics of health services, health behavior and outcomes.

La biología molecular en el estudio de la inmunopatología / Molecular Biology in the study of Immunopathology

Las técnicas de biología molecular han tenido un profundo impacto en el campo de la inmunología. Han permitido dilucidar varias interrogantes sobre el funcionamiento del sistema inmune y han aumentado nuestra habilidad para entender, diagnosticar y tratar una gran variedad de enfermedades inmunológicas. Se realizó una revisión de la literatura sobre aspectos generales de la importancia de las técnicas de biología molecular en el estudio de la respuesta inmune, que incluye conceptos generales y clasificación de las metodologías más empleadas, así como la referencia de algunas aplicaciones en el estudio de la inmunología y la inmunopatología. Se muestra información actualizada con enfoque analítico que permite ilustrar las características de los principales métodos empleados en biología molecular y su aplicación en el estudio de la respuesta inmune. La utilidad de las técnicas de biología molecular en el estudio de la respuesta inmune, ha constituido un poderoso instrumento para sus aplicaciones en el desarrollo de mejores alternativas diagnósticas y terapéuticas...

Molecular biology technical methods have caused a high impact in the field of immunology. They have made it possible to know the answer to many questions regarding the immune system function and have increased our ability to understand, diagnose and treat a great deal of immunological diseases. A review of the literature about the importance of molecular biology in the study of immune response was made, including general concepts, classification of the most used technologies, as well as some applications in the study of immunology and immunopathology. Update information with analytic view about the main methods used in molecular biology and its application in the evaluation of immune response is shown. Usefulness of molecular biology techniques are a powerfull instrument to develop new and better alternatives for diagnoses and treatment...

Lichen Planus in Four Clinical Forms.

Lichen planus is an autoimmune disorder which comes under lichenoid reactions. It is T-cell mediated cytotoxic reaction directed against antigen expressed by basal cell layer of the oral mucosa. Autoreactive T-lymphocytes may be of primary importance for the development of oral lichen planus. Lichen planus presentations in the oral cavity are in 6 forms: Reticular, papular, plaque, bullous, erythematous and ulcerative. We present a case report of 4 forms in a patient.

Study of anti nuclear and anti smooth muscle antibodies in patients with chronic obstructive pulmonary disease

Autoimmunity is a disease in which the immune system mistakenly attacks the body's own cells and tissues. Sometimes the whole body is attacked, and sometimes only one organ. The aim of this study was to evaluate antinuclear and anti smooth muscle antibodies, two common markers of autoimmunity, in COPD and their relation with different components of the disease and disease severity. The study included 50 clinically stable COPD patients classified into two groups mild to moderate [group A] and severe to very severe [group B] according to GOLD [2009] [13] criteria plus 30 healthy control subjects [15 smokers and 15 non smokers]. Blood levels of ANA and ASMA [measured by ELISA] were recorded. Levels of both ANA and ASMA were significantly higher in patients than in controls as a whole group but smoker controls showed significantly higher levels of both antibodies than mild to moderate COPD group [group A] indicating that not only smoking is responsible for COPD but other factors also play a role. Also high levels of these antibodies in smoker controls than in non smokers indicate a role of smoking in their development which is augmented by the direct relation with smoking index both in patients and controls. Both ANA and ASMA levels are elevated in COPD patients compared to controls [smokers and non smokers] and levels elevated in healthy smokers compared to group A COPD patients. Autoimmunity plays a role in the pathogenesis of COPD

Smooth muscle antibodies and cryoglobulinemia are associated with advanced liver fibrosis in Brazilian hepatitis C virus carriers

Cryoglobulinemia and non-organ-specific-autoantibody are biomarkers of autoimmunity of the chronic infection caused by hepatitis C virus (HCV). In this work, we report the association between the presence of smooth muscle antibodies (SMA) and cryoglobulinemia and chronic liver disease in HCV carriers. Sixty-five untreated HCV patients, 38 women and 27 men were included in this study. Cryoglobulinemia was tested by cryoprecipitation, SMA by indirect fluorescent antibody test, and liver fibrosis and hepatocellular inflammation activity was investigated by histology of liver biopsy using the METAVIR score. The prevalence of SMA in the patients was 33.8 percent and cryoglobulinemia was demonstrated in 36.9 percent patients. Cryoglobulinemia and SMA seropositivity was associated with advanced fibrosis (p < 0.05). The presence of SMA and cryoglobulinemia was not associated with hepatocellular inflammation activity, age, carrier gender or HCV genotype. We concluded that liver biopsy should be recommended for HCV carriers that are seropositive for SMA or cryoglobulinemia.

Persistence of goitre in the post-iodization phase: micronutrient deficiency or thyroid autoimmunity.

Background & objectives: Despite years of salt iodization, goitre continues to be a major public health problem worldwide. We examined the prevalence of goitre in the post-iodization phase and the relationship of goitre with micronutrient status and thyroid autoimmunity in school children of Chandigarh, north India. Methods: Two phase study; in the first phase, 2148 children of 6 to 16 yr were screened for goitre by two independent observers as per the WHO grading system. In the second phase, a case-control study, 191 children with goitre and 165 children without goitre were compared with respect to urinary iodine, iodine content of salt, serum levels of T3, T4, TSH, anti-TPO (thyroid peroxidase) antibody, haemoglobin, ferritin and selenium. Results: Prevalence of goitre in the studied subjects was 15.1 per cent (13.9% in 6 to 12 yr and 17.7% in 13 to 16 yr age group, P= 0.03). Median urinary iodine excretion in both the groups was sufficient and comparable (137 and 130 µg/l). 3.2 per cent children with goitre and 2.4 per cent without goitre had hypothyroidism (subclinical and clinical) and only one child with goitre had subclinical hyperthyroidism. Nine (4.9%) children in the goitre group and 3 (1.9%) in control group had anti-TPO antibody positivity. The median serum selenium levels were not different in both the groups (181.9 and 193.5 µg/l). Seventy one (37.4%) of the goitrous children had anaemia (haemoglobin <12 g/dl) as compared to 41 (24.8%) of the control group (P <0.01). More number of goitrous children (39, 20.6%) were depleted of tissue iron stores (serum ferritin <12 µg/l) as compared to controls (11, 6.4%; P<0.001). Serum ferritin level negatively correlated with the presence of goitre (r = - 0.22, P =0.008) and had an OR of 2.8 (CI 1.20 - 6.37, P =0.017). Interpretation & conclusions: There was a high prevalence of goitre in young children despite iodine repletion and low thyroid autoimmunity. The concurrent iron deficiency correlated with the presence of goiter. However, the cause and effect relationship between iron deficiency state and goitre requires further elucidation.

Contribution of dendritic cell/T cell interactions to triggering and maintaining autoimmunity

Under healthy conditions, there is a balance between tolerance to self-tissue constituents and immunity against foreign antigens. Autoimmunity diseases (AD) take place when that equilibrium is disrupted and the immune response is directed to self-antigens, leading to injury or destruction of host tissues. The mechanisms conducing to the loss of immune tolerance remain largely unknown. The recent appearance of biological therapies has contributed to significant reduction in morbidity. However, currently available therapies are associated with important side effects and work only as palliative treatments. Dendritic cells (DCs) have emerged as key players in developing and maintaining adaptive immunity due to their capacity to prime and modulate T cell function. Therefore, because DCs work as central modulators of immune tolerance, it is likely that alterations in their function can lead to the onset of autoimmune-inflammatory diseases. By modulating DC function, novel pathways in antigen-specific tolerance could be established. In this article, the possible contribution of altered DC-T cell interactions to the onset of autoimmunity are discussed. In addition, we expand on the notion that some of the functions of these cells could be relevant targets for intervening therapies aimed to restore the balance or even prevent the loss of tolerance.

The diagnosis and treatment of primary biliary cirrhosis / 대한간학회지

Primary biliary cirrhosis (PBC) is a slowly progressive cholestatic liver disease of autoimmune etiology. The initial presentation of PBC is various from asymptomatic, abnormal liver biochemical tests to overt cirrhosis. The diagnosis of PBC is based on cholestatic biochemical liver tests, presence of antimitochondrial antibody and histologic findings of nonsuppurative destructive cholangitis. Although the diagnosis is straightforward, it could be underdiagnosed because of its asymptomatic presentation, or underrecognition of the disease. UDCA in a dose of 13-15 mg/kg is the widely approved therapy which can improve the prognosis of patients with PBC. However, one-third of patients does not respond to UDCA therapy and may require liver transplantation. Every effort to diagnose PBC in earlier stage and to develop new therapeutic drugs and clinical trials should be made.

Sistema imunitário: parte III. O delicado equilíbrio do sistema imunológico entre os pólos de tolerância e autoimunidade / Immune system: part III. The delicate balance of the immune system between tolerance and autoimmunity

O sistema imunológico é constituído por uma intrincada rede de órgãos, células e moléculas e tem por finalidade manter a homeostase do organismo, combatendo as agressões em geral. A imunidade inata atua em conjunto com a imunidade adaptativa e caracteriza-se pela rápida resposta à agressão, independentemente de estímulo prévio, sendo a primeira linha de defesa do organismo. Seus mecanismos compreendem barreiras físicas, químicas e biológicas, componentes celulares e moléculas solúveis. A primeira defesa do organismo frente a um dano tecidual envolve diversas etapas intimamente integradas e constituídas pelos diferentes componentes desse sistema. A presente revisão tem como objetivo resgatar os fundamentos dessa resposta, que apresenta elevada complexidade e é constituída por diversos componentes articulados que convergem para a elaboração da resposta imune adaptativa. Destacamos algumas etapas: reconhecimento molecular dos agentes agressores; ativação de vias bioquímicas intracelulares que resultam em modificações vasculares e teciduais; produção de uma miríade de mediadores com efeitos locais e sistêmicos no âmbito da ativação e proliferação celulares; síntese de novos produtos envolvidos na quimioatração e migração de células especializadas na destruição e remoção do agente agressor; e finalmente a recuperação tecidual com o restabelecimento funcional do tecido ou órgão.

The immune system consists of an intricate network of organs, cells, and molecules responsible for maintaining the body's homeostasis and responding to aggression in general. Innate immunity operates in conjunction with adaptive immunity and is characterized by rapid response to aggression, regardless of previous stimulus, being the organism first line of defense. Its mechanisms include physical, chemical and biological barriers, cellular components, as well as soluble molecules. The organism first line of defense against tissue damage involves several steps closely integrated and constituted by different components of this system. The aim of this review is to restore the foundations of this response, which has high complexity and consists of several components that converge to articulate the development of adaptive immune response. We selected some of the following steps to review: perception and molecular recognition of aggressive agents; activation of intracellular pathways, which result in vascular and tissue changes; production of a myriad of mediators with local and systemic effects on cell activation and proliferation, synthesis of new products involved in the chemoattraction and migration of cells specialized in destruction and removal of offending agent; and finally, tissue recovery with restoration of functional tissue or organ.

Conexión entre inmunodeficiencia primaria y autoinmunidad / Connection between primary immunodeficiency and autoimmunity

Inmunodeficiencia y autoinmunidad constituyen 2 polos de la respuesta inmunitaria que pueden interrelacionarse con cierta frecuencia. En este artículo se exponen los síndromes autoinmunes que son causados por inmunodeficiencias primarias. También se describen otras inmunodeficiencias primarias como la inmunodeficiencia variable común, el síndrome de hiper Ig M, la deficiencia selectiva de Ig A, la hipogammaglobulinemia ligada al cromosoma X, el síndrome de Di George, la enfermedad granulomatosa crónica, el síndrome de Wiskott Aldrich y los defectos del sistema complemento, las que pueden asociarse con frecuencia variable con manifestaciones autoinmunes, fundamentalmente hematológicas. El principal mecanismo inmunopatogónico es la estimulación antigónica persistente, debido a un defecto del sistema inmune para erradicar patógenos; además, se incluyen los defectos de células T reguladoras, desregulación en la proliferación homeostática secundaria a linfopenia y factores genéticos

The immunodeficiency and the self-immunity are two poles the immune response that may have interrelation each other with some frequency. In present paper are showed the autoimmune syndromes caused by primary immunodeficiencies. Also, are described other primary immunodeficiencies including common variable immunodeficiency, the hyper Ig M syndrome, the selective of Ig A deficiency, the hypogammaglobulinemia linked to X chromosome, the Digeorge's syndrome, the chronic granulomatous diseases, the Wiskott Aldrich's syndrome, and the complement system defects, those that with a variable frequency may be associated with self-immune manifestations, mainly the hematologic ones. The immuno-pathogen leading mechanism is the persistent antigenic stimulation due to a immune system defect to remove pathogens; also, are included the regulatory T cells defects, deregulation in homeostatic proliferation secondary to linphopenia and genetic factors

Classificação do diabete melito / Diabetes mellitus classification

A correta classificação do diabete melito (DM) permite o tratamento mais adequado e compreende quatro categorias: DM tipo 1; DM tipo 2; Outros tipos e Diabete Gestacional. Em alguns casos, pode ocorrer sobreposição de quadros, principalmente no DM que inicia no adulto jovem ou que se apresenta inicialmente com cetoacidose, intermediários ao DM 1 e DM 2. Assim, acréscimos ao sistema de classificação clássico têm sido propostos, avaliando a presença de autoimunidade (anticorpos) e a função de célula β (peptídeo-C) para definir mais precisamente os subtipos. O objetivo desta revisão foi de analisar o desempenho desses índices diagnósticos para a classificação do DM e descrever os subtipos em detalhe. Os anticorpos contra o pâncreas evidenciam a autoimunidade, sendo o anticorpo contra insulina o mais acurado antes dos 5 anos de idade e o anti-descarboxilase do ácido glutâmico para início da doença acima dos 20 anos, é esse o teste que permanece positivo por mais tempo. Já a medida do peptídeo-C avalia a reserva pancreática de insulina, e os métodos de estímulo mais usados são a medida após refeição ou após glucagon endovenoso. Valores de peptídeo-C < 1,5 ng/ml definem o paciente com função pancreática ausente, e acima desse valor, com função preservada. Combinando-se a presença de anticorpos (A+) dirigidos ao pâncreas e a sua capacidade secretória de insulina (β+), pode-se subdividir a classificação do DM em tipo 1A (A+β-) e 1B (A+ β-); e o DM tipo 2 em subgrupos de DM 2A (A+β+) e DM 2B (A-β+), o que permite uma classificação e tratamento mais precisos, além de abrir os horizontes para o entendimento da patogênese do DM.

The right classification for diabetes mellitus (DM) allows a more adequate treatment and comprises four categories: type 1 DM, type 2 DM, other types, and gestational diabetes. In some cases, there might be a superposition of situations, especially with regard to the DM that initiates in the young adult or is initially presented with diabetic ketoacidosis intermediately to type 1 and 2 DM. Thus, additions to the classic classification system have been proposed as assessing the presence of autoimmunity (antibody) and b cell function (C-peptide) to precisely define the subtypes. The aim of this literature review was to analyze these diagnostic indexes’ performance in the DM classification and to describe subtypes with details. The antibodies against pancreas confirm autoimmunity, and the antibody against insulin is more accurate before 5 years old, while the anti-glutamic acid decarboxylase is more accurate after 20 years old, a test which remains positive for a longer period. The measurement of C-peptide evaluates the pancreatic insulin reserve, and the most largely used methods of stimulation are the measurement after meals or after intravenous glucagon. C-peptide values < 1.5 ng/ml define a patient with absent pancreatic function and, above this value, patients with preserved function. When the presence of antibodies (A+) directed to the pancreas is combined to its insulin secretion capability (β+), it is possible to subdivide DM’s classification in type 1A (A+β-) and 1B (A+β-); and type 2A (A+β+) and 2B (A-β+), which allows a more precise classification and treatment besides opening horizons for the understanding of DM pathogenesis.

T-cell protein tyrosine phosphatase: a role in inflammation and autoimmunity

A cDNA of PTPN2 encoding for T-cell protein tyrosine phosphate [TC-PTP] was isolated and characterized as long as 20 years ago. However, findings suggesting a potentially exciting role of this enzyme in general autoimmunity have only recently been obtained. Genome-wide association scans of the human genome revealed the involvement of PTPN2 in susceptibility to a several autoimmune disorders such as Crohn's disease, type 1 diabetes, and Graves' disease. Functional studies in immune cells revealed a key role of this enzyme in down-regulation of cytokine expression and inflammatory response, which provides an essential background to explaining the pathophysiological role of TC-PTP in autoimmunity. Thus, in addition to PTPN22, PTPN2 is likely to represent a second member of the broad family of non-receptor PTPs contributing to general autoimmunity

Conceptos emergentes de tolerancia y autoinmunidad: Nuevos enfoques terapéuticos / Tolerance and autoimmunity: Novel therapeutic approaches

La función primaria del sistema inmune es resguardar al individuo de los patógenos potencialmente dañinos que invaden el medio ambiente en el cual nos desarrollamos. Este cuenta con dos grandes ramas, la inmunidad innata y la adaptativa, ambas con la propiedad de diferenciar lo peligroso de aquello inofensivo. Estos procesos se hallan regulados por mecanismos homeostáticos que constituyen la tolerancia inmunológica, a los fines de limitar aquellos procesos prolongados y silenciar los potencialmente autoagresivos. Ante la falla de estos mecanismos de control, surgen las enfermedades autoinmunes. Avances en el conocimiento de la fisiopatología de estas entidades, han abierto un nuevo capítulo en el terreno de la inmunofarmacología. Su prometedor potencial actualmente nos ofrece novedosas herramientas terapéuticas para controlar y atenuar el daño causado por este tipo de respuestas. No obstante, debe continuarse la investigación en el campo de los agentes biológicos, ya que ninguno de ellos se encuentra libre de inconvenientes. Seguramente, futuros hallazgos se concretarán en futuros aciertos. Y los aciertos, en Medicina, equivalen a esperanza.

The main function of the immune system is to protect the individual against potentially dangerous pathogens. It comprises innate and adaptive cellular and soluble components, both with the capacity to discriminate between harmful and harmless. These processes are regulated by homeostatic mechanisms that constitute the so-called immunological tolerance, which aims to limit the prolonged action of immune mediators and to silence the generation of potentially autoaggressive components. Failure to silence self-reactive T and B cells results in the generation of autoimmune disease. Recent advances in our knowledge of these pathological entities have opened a new chapter in the pharmacology of the immune system. Its promising potential currently offers new therapeutic agents to control and attenuate pathological tissue damage. Nevertheless, further research regarding these biologic agents is required, since they are not free from inconveniences. It is without question that upcoming findings in this field will instill hope into the quest for the "magic bullet".

Infecciones por HSV-2 y su relación con anticuerpos antiencéfalo de rata en suero de pacientes con autismo / Association between HSV-2 infection and serum anti-rat brain antibodies in patients witn autism

Algunos casos de autismo podrían estar vinculados a infecciones virales capaces de inducir mecanismos autoinmunes dirigidos contra el encéfalo. Las infecciones de virus neurotrópicos en animales se acompañan de síntomas similares a los observados en los trastornos del neurodesarrollo. Así, en este estudio evaluamos la co-existencia de anticuerpos contra tejido nervioso y contra virus con capacidad neurotrópica [HSV-1/2, Epstein-Barr (EBV), citomegalovirus, sarampión y rubéola] en el suero de cuarenta niños autistas y cuarenta niños sanos. La presencia de anticuerpos contra tejido nervioso se detectó en cortes de tejido encefálico de rata mediante inmunofluorescencia indirecta. Los niveles de anticuerpos IgG e IgM anti-virales se midieron por ELISA indirecta. La proporción de autistas con anticuerpos IgG anti-encéfalo (77% anti-amígdala, 70% anti-núcleo caudado, 47,5% anti-cerebelo y anti-tallo cerebral, 45% anti-hipocampo, 40% anti-cuerpo calloso y 17,5% anti-corteza) fue significativamente mayor que aquella de los controles (10% anti-amígdala y 5% anti-cerebelo) y se relacionó directamente con la severidad del autismo. La proporción de niños con niveles positivos (mayores a 1,1 mg/dL) para anticuerpos IgM anti-HSV (indicativo de infección aguda) fue significativamente mayor en autistas (65%) que en sanos (17,5%). El 96% de los autistas con anticuerpos anti-HSV también presentó anticuerpos anti-encéfalo, porcentaje que fue significativamente mayor que el de los autistas negativos al anticuerpo anti-HSV (43%). En contraste, no hubo diferencias significativas para los anticuerpos IgG e IgM para EBV, citomegalovirus, sarampión y rubéola. Esto sugiere que una autoinmunidad contra estructuras encefálicas desencadenada por infecciones por HSV podría estar involucrada en el autismo.

Some cases of autism could be linked to viral infections able to induce autoimmune mechanisms directed against the encephalon. Neurothophic virus infections in animals are associated with clinical signs that are similar to those observed in neurodevelopment disorders. Thus, in this study, we determined the co-existence of antibodies against nerve tissue and viruses with neurothophic competence (HSV-1/2, Epstein-Barr-EBV, cytomegalovirus, measles and rubella) in serum of forty autistic children and forty healthy children. The presence of antibodies against nerve tissue was detected in slices of rat encephalic tissue by indirect immunofluorescence. The levels of anti-viral IgG and IgM antibodies were measured by indirect ELISA. The proportion of autistics with anti-encephalon IgG antibodies (77% anti-amygdala, 70% anti-caudate nucleus, 47.5% anti-cerebellum y anti-brain stem, 45% anti-hippocampus, 40% anti-corpus callosum and 17,5% anti-cortex) was significantly greater than that of controls (10% anti- amygdala y 5% anti- cerebellum) and was directly related to the severity of the autism. The proportion of children with positive levels (greater than 1.1.mg/dL) for anti-HSV IgM antibodies (indicative of acute infection) was significantly greater in autistics (65%) than in healthy children (17.5%). Ninety six percent of the autistics with anti-HSV antibodies also had anti-encephalon antibodies, percentage that was significantly greater than that of autistics negative to the anti-HSV-antibody (43%). In contrast, there were no significant differences for IgG and IgM antibodies for EBV, cytomegalovirus, measles and rubella. This suggests that autoimmunity against encephalic structures elicited by HSV infections could be involved in autism.

Immunopathology in ocular toxoplasmosis: facts and clues

Although parasite-mediated host cell lysis is deemed to be an important cause of tissue destruction in ocular toxoplasmosis (OT), the severity of the disease is probably correlated with hypersensitivity and inflammation. Notwithstanding, the mechanisms that regulate the inflammatory process in recurrent OT are poorly understood. Recent evidence has identified interleukin (IL) 17 as a marker for disease severity. The ocular and cerebral presence of this cytokine is generally associated with the induction of autoimmune responses in the brain and the eye. Indeed, there are indications that autoimmunity may contribute to clinical variability in the activity of OT. IL-23, which induces the proliferation of IL-17-producing cells and IL-27, which is a counterplayer to IL-17, may regulate T(H)-1-cell-mediated responses in OT. The importance of these cytokines in experimental models of uveitis and encephalitis has been recently reported. CD25(+) regulatory T-cells may control the local inflammatory response and protect the host against collateral inflammatory tissue damage. The responses of these cells to OT may be suitably tailored to cope with either an acquired or a congenital aetiology. Knowledge relating to immunoreactivity in OT has grown impressively during the past few years. Its characteristic and variable features have been identified and the potential relevance of autoimmunity has been assessed. In light of this knowledge, potential future treatment options have been considered.