Η λεπτίνη είναι μια ορμόνη 16 kD που κωδικοποιείται απότογονίδιο obκαι παράγεται από τα λιποκύτταρα ρυθμίζοντας το ενεργειακό ισοζύγιο. Τα επίπεδα λεπτίνης στο πλάσμα είναι ανάλογα με το δείκτη σωματικής μάζας (BMI), ενώ η έκφρασή της εξαρτάται από τη νηστεία και τη σίτιση, την ινσουλίνη, τα γλυκοκορτικοειδή, καθώς και από προφλεγμονώδεις κυτταροκίνες, κύριως τον TNF-α και την IL-1. Το μόριο της λεπτίνης παρουσιάζει ομοιότητες με τη μακριά έλικα των κυτταροκινών και δρά μέσω του υποδοχέα της (OB-R), ο οποίος ανήκει στην υπεροικογένεια των υποδοχέων των κυτταροκινών και εμφανίζεται σε ποικιλία ισομορφών ενώ εκφράζεται σε διάφορους ιστούς και κύτταρα του νευροενδοκρινικού, αναπαραγωγικού, αιματοποιητικού και ανοσοποιητικού συστήματος. Η λεπτίνη εμπλεκεται και σε αυτοάνοσες καταστάσεις με το να προάγει τη διατήρηση παθογόνων Th1 κυτταρικών υποπληθυσμών. Στην παρούσα μελέτη προκειμένου να διερευνήσουμε το ρόλο της λεπτίνης σε αυτοάνοσες καταστάσεις μετρήσαμε τα επίπεδα αυτής και του υποδοχέα της σε ασθενείς με ρευματοειδή αρθρίτιδα, μια χρόνια συστεμική αυτοάνοση νόσο, για να δούμε εάν αυτά σχετίζονται με το στάδιο της νόσου ή τη θεραπεία. Ακόμη μελετήθηκε η εμπλοκή της λεπτίνης στην έκφραση προ- και αντιφλεγμονωδών κυτταροκινών στον ορό ασθενών και μαρτύρων. Τα αποτελέσματα δείχνουν πως τα επίπεδα λεπτίνης είναι υψηλά στους ασθενέις με ΡΑ. Επιπλέον τα επίπεδα λεπτίνης δεν βρέθηκε να σχετίζονται με το στάδιο της νόσου ή τη χορηγούμενη θεραπεία. Παρόλα αυτά τα αυξημένα επίπεδα λεπτίνης σε ασθενείς με ρευματοειδή αρθρίτιδα καταδεικνύουν ενδεχομένως έναν παθογενετικό ρόλο της λεπτίνης. / Leptin is a 16 kD peptide hormone, encoded by the ob gene and synthesized mainly by adipocytes to regulate the energy balance. In humans, leptin plasma levels are strongly correlated with body mass index (BMI) and the expression of leptin is regulated by fasting and feeding, insulin, glucocorticoids and pro-inflammatory cytokines, mainly TNFa and IL-1. Leptin is structurally similar to long-chain helical cytokines and it signals through its receptor, OB-R, which is a member of the cytokine receptor superfamily. OB-R comes in a variety of protein isoforms, and is expressed in several tissues and cells of the neuroendocrine system as well as the reproductive, hematopoietic and immune systems. Leptin has also been implicated in the pathogenesis of autoimmunity. It has also been suggested that leptin may promote the expansion and maintenance of pathogenic Th1-cell populations in autoimmune diseases. In this study to investigate the role of leptin in human autoimmunity, we measured leptin and OB-Rs levels inthe sera of patients suffering from rheumatoid arthritis (RA), a common chronicsystemic inflammatory disease, and tested for a possible correlation with disease activity and type of treatment. In addition, we studied whether leptin has an effect on the expression patterns of pro- and anti-inflammatory cytokine genes in PBMC isolated from RA patients and controls.Our results showed significantly elevated serum leptin levels in the rheumatoid population compared to the healthy controls.In addition, there was an absence of correlation between serum leptin levels and disease activity, as well as the nature and quantity of the medications administered to the patients. The absence of correlation between serum leptin levels and disease activity, coupled with the significantly and stably elevated levels of this hormone in the rheumatoid sera compared to the controls, are probably indicative of an insiduous pathogenetic role of leptin in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a debilitating chronic inflammatory disease causing bone and cartilage degradation. Macrophages are known to play a role in RA pathology by producing pro-inflammatory cytokines and chemokines, which activates immune cells, drives inflammation and facilitates the degradation of bone and cartilage. Alterations in epigenetic mechanisms, processes that regulate gene expression, have been implicated in the regulation of pro-inflammatory cytokines in RA. Therefore, the aim of this thesis was to determine specific epigenetic variation between RA patient blood and synovial fluid (SF)-derived macrophages (SF MLS). Granulocyte and macrophages colony stimulating factor (GM-CSF) was used to differentiate healthy donor and RA patient blood monocytes into macrophages. Lipopolysaccharide (LPS) was used to stimulate blood and SF-derived macrophages to initiate inflammatory cytokine production. A library of small molecule inhibitors was used to identify key epigenetic regulators of pro-inflammatory cytokine production. Bromodomain and extra-terminal (BET) protein inhibitors (JQ1, I-BET151, PFI-1) were the only class of inhibitor to show consistent down regulation of pro-inflammatory cytokines in both healthy and RA patient-derived macrophages. However, only JQ1 was shown to reduce TNFα production significantly in SF MLS. Transcriptional profiling of RA patient SF MLS indicated a preference for a pro-inflammatory phenotype, and a resistance to steroids (a trait found in 30% of RA patients); SF MLS production of chemokines and cytokines were not downregulated by glucocorticoids in comparison to corresponding blood-derived macrophages. However, JQ1 treatment successfully suppressed these genes. In addition, silencing of BRD4 in blood-derived macrophages from healthy donors reduced pro-inflammatory cytokine production. Chromatin immunoprecipitation studies showed BRD4 was localised to pro-inflammatory promoter regions upon LPS stimulation and displaced in the presence of JQ1. These studies identified BET proteins BRD2, 3 and 4, as essential epigenetic regulators of pro-inflammatory cytokine and chemokine production in both healthy donors and RA patient macrophages. Furthermore, the observation that BET inhibitors can regulate genes that are steroid resistant in RA patient SF MLS, highlights their therapeutic potential in RA.

Orientador: Alexandrina Sartori / Banca: Liana Maria Cardoso Verinaud / Banca: Vânia Luiza Deperon Bonato / Banca: Angela Maria Victoriano de Campos Soares / Banca: Paula Schmidt Azevedo Gaiolla / Resumo: A artrite reumatoide (AR) é uma doença autoimune que compromete as articulações. A maioria das terapias utilizadas para o seu tratamento é baseada na inibição global da resposta imune, podendo aumentar a susceptibilidade a agentes infecciosos. O objetivo geral deste projeto foi definir estratégias tolerogênicas específicas para profilaxia ou terapia da AR. Para isso, em uma primeira etapa, estabelecemos um modelo de artrite induzida por proteoglicano (PG) bovino. Camundongos BALB/c fêmeas retired breeders imunizados com PG bovino associado ao adjuvante brometo de dimetil dioctadecil amônio apresentaram os sinais clínicos característicos da artrite, como eritema e edema decorrentes da inflamação articular de uma ou mais patas. A análise histopatológica mostrou a presença de hiperplasia sinovial, infiltrado inflamatório (formação de pannus), destruição da cartilagem e erosão óssea. A incidência da doença foi de 100% e os animais artríticos produziram níveis significativos de citocinas pró e anti-inflamatórias e anticorpos IgG1 e IgG2a anti-PG. Em uma segunda etapa, testamos o potencial profilático do PG. A inoculação de três doses de 50 μg de PG determinou um efeito profilático caracterizado pela diminuição significativa da incidência da artrite e do escore clínico dos animais. A diminuição da produção de IFN-g e IL-17, bem como o aumento da produção de IL-4 e IL-10 por células esplênicas estimuladas com PG, podem estar contribuindo para o efeito profilático observado neste grupo. Em uma terceira etapa, avaliamos o potencial terapêutico da associação da vitamina D ativa (VitD3) com o PG. A associação VitD3+PG determinou um efeito terapêutico na artrite experimental caracterizado por diminuição significativa do escore clínico. Este feito foi confirmado pela análise histopatológica que revelou que a maioria das patas do grupo tratado apresentou estrutura articular bem preservada, ... / Abstract: Rheumatoid arthritis (RA) is an autoimmune disease that affects the joints. Most of the therapies used for RA treatment are based on general suppression of immune response, which may increase the susceptibility to infectious agents. The main objective of this work was to establish specific tolerogenic strategies for prophylaxis or therapy of RA. For this purpose, we first established a model of arthritis induced by bovine proteoglycan (PG). Female BALB/c retired breeder mice immunized with bovine PG associated with dimethyl-dioctadecyl ammonium bromide adjuvant developed a typical arthritis characterized by erythema and edema resulting from joint inflammation of one or more paws. Histopathological analysis showed the presence of synovial membrane hyperplasia, inflammatory infiltrates (pannus formation), cartilage destruction and bone erosion. Disease incidence was 100% and the arthritic mice produced significant levels of pro and anti-inflammatory cytokines and IgG1 and IgG2a anti-PG antibodies. Further, we tested the prophylactic potential of PG. Three doses of 50 μg of PG determined a prophylactic effect characterized by a significant decrease in both, arthritis incidence and clinical scores. The decrease in IFN-g and IL-17, as well as the increase in IL-5 and IL-10 production by spleen cells stimulated with PG may be contributing to the prophylactic effect observed in this group. Lastly, we evaluated the therapeutic potential of the combination of active vitamin D (VitD3) with PG. The VitD3+PG association determined a therapeutic effect in experimental arthritis. There was a significant decrease in the clinical scores after VitD3+PG treatment that was confirmed by the histopathological analysis. Most mice paws from the treated group presented well preserved joint structures that were similar to the ones present in healthy animals. Both pro and anti-inflammatory cytokines were decreased after this treatment. No differences were ... / Doutor

Introdução: A atrite reumatoide (AR) é uma doença Inflamatória crônica de etiologia desconhecida que afeta principalmente as articulações. A evolução da doença está associada com a incapacidade funcional, aumentando o risco de doenças cardiovasculares (DCV) e disfunção endotelial e rigidez arterial. Objetivo: Avaliar os efeitos de uma única sessão de exercício aeróbico de alta intensidade na função endotelial mediada pelo fluxo (DMF), avaliar a dor no pré exercício e após uma semana de intervenção através da escala visual analógica (EVA) e rigidez arterial em pacientes 26 com AR. Métodos: Estudo quase experimento, com 22 pacientes portadores de AR leve a moderada. Foram realizados teste ergoespirométrico, ecografia braquial para determinar a dilatação mediada pelo fluxo (DMF) e a avaliação da rigidez arterial por determinação da velocidade de onda de pulso (VOP), pré, pós e uma hora após a aplicação de um protocolo de treinamento intervalado de alta intensidade (TIAI). Resultados: A média de idade dos participantes é de 59,2 + 7,6 anos e há predominância do sexo feminino (91%). Apresentaram DAS28 de 4,1+ 1,0 (atividade moderada), e HAQ de 1+ 0,6 pontos (deficiência moderada). O VO2 Máximo encontrado foi de 21,19 + 3,89 ml/Kg/min. Os valores de DMF nos três momentos foram: basal com hiperemia reativa (10,59+0,47) e com nitroglicerina spray sublingual (12,66+0,89), no pós imediato (10,69+ 0,39) e com nitroglicerina (12,93+0,58), e 1 hora após (10,93+0,29) e com o medicamento (13,20+0,46), em relação a escala analógica visual de dor (EVA) observamos no basal uma dor de (3,45+0,80) e pós uma semana de intervenção (2,50+0,51). Conclusão: Concluímos que o TIAI com portadores de AR não foi significativo em relação às porcentagens de DMF, mas quando observamos outras medidas como a VOP, Pressão Arterial, Pressão de Pulso e o Índice de Aumentação, e os pacientes não apresentaram dor após uma semana de intervenção, sendo assim o exercício parece ser eficiente, sugerindo que pode ser uma estratégia útil para a prevenção de DCV em pacientes com AR. / Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown etiology that mainly affects the joints. The evolution of the disease is associated with functional disability, increasing the risk of cardiovascular diseases (CVD) and endothelial dysfunction and arterial stiffness. Objective: To evaluate the effects of a single high-intensity aerobic exercise session on flow-mediated endothelial function (DMF), evaluate pain in pre-exercise and after one week of intervention using visual analogue scale (VAS) and arterial stiffness in patients with AR. Methods: Almost experimental study with 22 patients with mild to moderate RA. An ergospirometric test, brachial ultrasound was performed to determine the flow-mediated dilatation (FMD) and the evaluation of arterial 53 stiffness by determination of the pulse wave velocity (VOP), pre, post and one hour after the application of an interval training protocol high intensity (TIAI). Resultados: A média de idade dos participantes é de 59.2 + 7.6 anos e há predominância do sexo feminino (91%). Apresentaram DAS28 de 4.1+ 1.0 (atividade moderada), e HAQ de 1+ 0.6 pontos (deficiência moderada). O VO2 Máximo encontrado foi de 21.19 + 3.89 ml/Kg/min. Os valores de DMF nos três momentos foram: basal com hiperemia reativa (10.59+0.47) e com nitroglicerina spray sublingual (12.66+0.89), no pós imediato (10.69+ 0.39) e com nitroglicerina (12.93+0.58), e 1 hora após (10.93+0.29) e com o medicamento (13.20+0.46), em relação a escala analógica visual de dor (EVA) observamos no basal uma dor de (3.45+0.80) e pós uma semana de intervenção (2.50+0.51). Conclusion: We conclude that the TIAI with RA patients was not significant in relation to DMF percentages, but when we observed other measures such as OPV, Blood Pressure, Pulse Pressure and Increasing Index, and patients did not present pain after one week the exercise appears to be efficient, suggesting that it may be a useful strategy for the prevention of CVD in patients with RA.

Leflunomide is widely prescribed for Rheumatoid Arthritis (RA) patients in China. However, a number of RA patients still demonstrated progressive bone erosion (PBE+) after receiving Leflunomide in our clinical data. Moreover, the PBE+ is predicted by high baseline serum CRP level (CRPBH). Further, the changes of serum bone resorption marker (Tartrate-resistant acid phosphatase 5b, TRAP5b) strongly correlated with those of CRP in PBE+ RA patients during Leflunomide treatment. Those were consistently observed in collagen-induced-arthritis (CIA) rats. To precisely address the issue, we screened a series of marketed drugs combined with Leflunomide to inhibit CRP production and CRP-related osteoclastic signaling pathway using bioinformatics analysis. Ligustrazine was postulated as an optimal candidate drug. In vitro studies demonstrated that the combination of Ligustrazine and Leflunomide not only suppressed hepatic CRP production, but also suppressed CRP-related osteoclastic signaling and osteoclast activities. In vivo studies showed that the combination attenuated bone erosion in CIA rats. Further, the randomized parallel controlled clinical trial in 120 CRPBH RA patients showed that the combination therapy reduced serum CRP levels and attenuated bone erosion in those patients (ChiCTR-TRC-10001014). Together, this work presents a precision combination therapy for PBE+ in CRPBH RA patients.

Staphylococcus aureus est une des espèces bactériennes les plus fréquemment responsable des cas d’endophtalmie et d’arthrite aiguës chez l’homme. Nous avons étudié la pharmacodynamie oculaire du linézolide et de la daptomycine, ainsi que leur toxicité, dans un modèle d’endophtalmie expérimentale chez le lapin. Il est apparu que seule une dose très élevée delinézolide administrée par voie intravitréenne (30mg/0,1mL) présentait une efficacité bactérioclinique. Aucune altération de la fonction visuelle n’a été mise en évidence. La dose intravitréenne efficace de daptomycine (1mg/0,1mL) était quant à elle responsable d’une altération significative de l’intégrité fonctionnelle de la rétine. Enfin, la pharmacodynamie de ces deux antibiotiques dans le compartiment oculaire présentait des différences significatives avec les autres sites tissulaires d’infection étudiés à ce jour. Dans la deuxième partie de nos travaux nous nous sommes intéressés à une nouvelle technique d’IRM, associée à des particules d’USPIOs (Ultrasmall SuperParamagnetic Iron Oxide). Nous avons montré que cette techniqued’imagerie permettait d’une part la mise en évidence de l’infiltration des macrophages dans la synoviale infectée, et, d’autre part, la visualisation de la guérison de l’articulation, contrairement à l’imagerie conventionnelle à base de chélates de gadolinium. Cette technique innovante offre donc une nouvelle dimension à l’imagerie ostéo-articulaire grâce à une mise en évidence in vivo plus spécifique des phénomènes pathologiques. / Staphylococcus aureus (S. aureus) is a frequent cause of acute endophthalmitis and arthritis in humans. In the first part, we investigated the ocular pharmacodynamics and safety of two recently approved antistaphylcoccal antibiotics, linezolid and daptomycin. Only a very high intravitreal dose of linezolid (30 mg / 0.1 mL) showed a bactericidal and clinical efficacy. Suchintraocular concentrations appeared to be safe for the retinal function, and linezolide could be considered as a promising therapeutic alternative. The effective intravitreal dose of daptomycin (1 mg / 0.1 mL) was responsible for a significant impairment of the functional integrity of the retina. Finally, the ocular pharmacodynamics of these two antibiotics showed special features in comparison with the one of other types of tissue infection. In a second part, we evaluated a newimaging method in experimental infectious arthritis, by using MRI enhanced by ultrasmall superparamagnetic iron oxide (USPIO). We first showed this method can depict the macrophage infiltration in infected synovium, and secondly it can demonstrate resolution of joint infection, in contrast to conventional MRI performed by gadolinium chelates. This in vivo non invasive imaging method therefore presents a new dimension in musculoskeletal imaging by accurately helping monitor bacterial joint infection.

Objetivos: Avaliar associações da velocidade de crescimento com marcadores inflamatórios e dose cumulativa de glicorticóide em uma coorte de pacientes com Artrite Idiopática Juvenil acompanhados por 1 ano. Material e Métodos: Foram avaliados 79 pacientes com AIJ segundo critérios da ILAR. A atividade clínica da doença foi classificada por médicos reumatologistas pediátricos. Os dados antropométricos foram mensurados e classificados de acordo com as normas da Organização Mundial da Saúde. Foram utilizadas curvas de velocidade de crescimento segundo Tanner; considerou-se baixa velocidade de crescimento valores de escore Z ≤ -2. Concentrações séricas de IL-6 foram mensuradas por ELISA no período basal, e valores acima de 1 pg/ml foram considerados elevados. Resultados: Baixa velocidade de crescimento teve uma prevalência de 25,3% e esteve associada com atividade da doença no período do seguimento (p=0,085), valores elevados de IL-6 (interleucina-6) (p=0,003), velocidade de sedimentação globular (VSG) (p=0,022) e proteína C reativa (PCR) (p=0,001) e maior dosagem cumulativa de glicocorticóide (0=0,044). Na regressão linear múltipla tendo como variável dependente a velocidade de crescimento, observou-se que somente os níveis elevados de IL-6 foram independente e negativamente associados com a velocidade de crescimento (p=0,025). Conclusão: Baixa velocidade de crescimento é altamente prevalente em crianças com AIJ. Níveis elevados de IL-6 têm um importante impacto negativo no crescimento desses pacientes, enquanto a exposição ao glicocorticóide total parece ser um fator secundário. / Objective: To evaluate associations of growth velocity with inflammatory markers and cumulative dose of glucocorticoid in a cohort of patients with Juvenile Idiopathic Arthritis (JIA) followed during 1 year. Methods: Seventy-nine patients were evaluated by criteria according to the ILAR. The disease activity was evaluated by a pediatric rheumatologist. The anthropometic data were measured and classified according to the World Health Organization standards. Growth velocity curves were used according to Tanner, values below the Z-score ≤ -2 were considered low growth velocity. Serum concentrations of IL-6 were measured by ELISA in the baseline period, and values over 1pg/ml were considered as elevated. Results: The prevalence of low growth velocity was 25.3%, and it was associated with: active disease on follow-up visit (p=0,085), elevated interleukin-6 (IL-6) (p=0,003), erythrocyte sedimentation rate (ESR) (p=0,022) and C-reactive protein (CRP) (p=0,001) and higher cumulative glucocorticoid doses (0=0,044). In the multiple linear regression with growth velocity as the dependent variable, only elevated IL-6 levels were independently and negatively associated with growth velocity (p=0,025). Conclusion: Low growth velocity is highly prevalent in children with JIA. Elevated IL-6 levels seem to have an important negative impact on growth in these children, while total glucocorticoid exposure appears to be a secondary factor.

A Artrite idiopática juvenil (AIJ) é a artropatia crônica mais prevalente na infância e adolescência. A prevalência da síndrome metabólica, assim como da obesidade, vem apresentando um rápido aumento, atingindo todas as faixas etárias, incluindo a infância. A síndrome metabólica é caracterizada por um conjunto de riscos para doença cardiovascular e diabetes melito tipo 2, incluindo adiposidade abdominal, resistência à insulina, dislipidemias e hipertensão arterial sistêmica. Além destes componentes, a inflamação tem sido reconhecida cada vez mais como um fator importante na síndrome metabólica e obesidade, e pacientes com doenças caracterizadas por processos inflamatórios crônicos, como a AIJ, poderiam representar grupos de risco especiais. Os glicocorticoides são utilizados rotineiramente no controle da inflamação da artrite idiopática juvenil, em doses elevadas e com uso prolongado. O uso crônico do glicocorticoide pode induzir resistência à insulina, hipertensão arterial sistêmica e obesidade, aumentando o risco de desenvolver síndrome metabólica. O presente trabalho tem como objetivo avaliar a prevalência de obesidade e síndrome metabólica em pacientes com AIJ. Em pacientes acompanhados no Serviço de Reumatologia do Hospital de Clínicas de Porto Alegre (HCPA) e Hospital da Criança Santo Antônio (complexo Santa Casa) foram observados uma prevalência de 19,7% de síndrome metabólica e 22,7% de obesidade, sem diferença entre os subtipos da doença. A obesidade foi associada com tempo de duração da doença, obesidade abdominal, pressão arterial elevada, resistência à insulina e presença de síndrome metabólica. O IMC, circunferência da cintura, triglicerídeos, baixos níveis de HDL-c, pressão arterial sistólica e diastólica, níveis séricos de insulina e resistência a insulina (HOMA-ir) mostraram associação com a SM (p<0,05). Não houve associação entre a presença de SM e dose cumulativa de glicocorticoide, atividade da doença e tempo de duração da doença. Os resultados mostram uma alta frequência de obesidade e síndrome metabólica em pacientes com AIJ, sugerindo um aumento do risco de futuras complicações cardiovasculares. e parecem ser independentes do uso de glicocorticoide. Ações de intervenção são necessárias entre os pacientes com AIJ para reduzir o excesso de peso, evitar as complicações metabólicas e fatores de risco cardiovasculares na vida adulta. / Juvenile idiopathic arthritis is the most prevalent chronic arthropathy in childhood and adolescence. The prevalence of metabolic syndrome, as well as obesity, is increasing fast, in all age groups, including the childhood. Metabolic syndrome is defined as a cluster of risk factors for cardiovascular and type 2 diabetes, including abdominal obesity, insulin resistance, dyslipidaemia and hypertension. Besides these components, inflammation has been increasingly considered as a significant component in metabolic syndrome and obesity, and patients with diseases characterized by the presence of chronic inflammation, such as JIA, could represent special groups of risk. Glucocorticoids are used routinely in the management of the inflammation of JIA, in high doses and long-term. Long-term use of the glucocorticoids can cause insulin resistance, hypertension and obesity, increasing the risk for the metabolic syndrome. The aim of the present study was to evaluate prevalence of the obesity and metabolic syndrome in patients with juvenile idiopathic arthritis (JIA). In patients followed in the Hospital de Clínicas de Porto Alegre (HCPA) and Hospital da Criança Santo Antônio (Santa Casa Complex) service of reumatology were observed a prevalence of 19.7% of metabolic syndrome and 22.7% of obese, without difference between the subtypes of the disease. Obesity was associated with disease duration, abdominal obesity, arterial hypertension, insulin resistance and presence of metabolic syndrome. BMI, waist circunference, triglycerides, low HDL-c level, systolic and diastolic BP, fasting insulin serum levels and insulin resistance (HOMA-ir) showed significant association with MetS (p<0,05). There was no correlation between the presence of metabolic syndrome and cumulative glucocorticoid dose, disease activity and duration of disease. The results showed that there were high frequencies of obesity and metabolic syndrome in JIA patients and use appears to be indeoendent of the use glucocorticoid. Intervation actions are needed among JIA patients, to decrease excess weight, metabolic complications and cardiovascular risk factors in adulthood.

Base Teórica: A artrite reumatoide (AR) é uma doença crônica e inflamatória que além de sintomas articulares pode levar à perda de massa muscular com peso estável ou aumentado, condição denominada caquexia reumatoide (CR). A CR está associada com pior prognóstico, mas ainda é negligenciada na prática clínica. Objetivo: Avaliar a prevalência de CR em um hospital público terciário de Porto Alegre e determinar sua correlação com características da AR, com níveis de atividade física e com as medicações em uso. Métodos: Estudo transversal com 91 pacientes com AR que foram submetidos à densitometria corporal total (DEXA) para medida total e regional de índice de massa gorda (IMG; Kg/m2), índice de massa magra (IMM; Kg/m2), conteúdo mineral ósseo (CMO) e índice de massa livre de gordura (IMLG; Kg/m2) para avaliar a prevalência de CR pelas duas definições mais recentemene utilizadas na literatura: IMLG < percentil 10 com IMG > percentil 25 e IMLG < percentil 25 com IMG > percentil 50. Foram exploradas as medidas de associação dos parâmetros de composição corporal com características da AR – idade, duração da doença, atividade de doença (através do DAS 28), capacidade funcional (através do HAQ), atividade inflamatória (através da proteína C reativa – PCR – e velocidade de hemossedimentação – VHS), nível de atividade física (através do questionário IPAQ) e medicações em uso. Resultados: A idade média dos participantes foi 56,8 ± 7,3, a duração de doença foi 9 anos (3-18), o DAS 28 3,65 ± 1,32, o HAQ 1,12 (0,25 – 1,87) e o tempo de uso entre os que usaram biológico foi de 25 meses (17,8 – 52,5). A CR foi evidenciada em 17,6% dos pacientes com AR de acordo com a definição mais rigorosa e em 33% de acordo com a classificação mais abrangente. O IMLG teve correlação negativa com idade (r= -0,219; p=0,037) e duração da doença (rs= -0,214; p=0,042). O IMG teve correlação positiva com PCR (rs=0,229; p=0,029), VHS (rs=0,235; p=0,025), DAS 28 (rs=0,273; p=0,009) e HAQ (rs=0,297; p=0,004). Na comparação de pacientes com e sem CR, de acordo com a definição mais rigorosa, dos 26 pacientes usando biológico apenas 1 tinha CR (3,8%), enquanto dos que não usavam, 15 (23%) tinham CR (p=0,033). Conclusão: A prevalência de CR foi considerável e, portanto, merece estudos adicionais. A composição corporal neste estudo, especialmente o IMLG, teve associação inversa com idade e tempo de diagnóstico. Além disso, pacientes em uso de biológico tiveram diferença significativa na prevalência de CR, sugerindo papel protetor do uso de biológico na CR. / Background: Rheumatoid arthritis (RA) is a chronic and inflammatory disease that besides articular symptoms leads to loss of muscle mass in presence of stable or increased fat mass (FM), condition defined as rheumatoid cachexia (RC). RC is associated with a worse prognosis, but it is still overlooked in clinical practice. Objective: To evaluate the prevalence of rheumatoid cachexia (RC) in patients with rheumatoid arthritis (RA) and determine its correlation with the features of RA, the level of physical activity and with the current therapy. Methods: Ninety one RA patients in a cross-sectional study underwent total body dual-energy x-ray absorptiometry (DXA) for measurement of total and regional fat mass index (FMI; Kg/m2), lean mass index (LMI; Kg/m2), bone mineral content (BMC; Kg/m2) and fat free mass index (FFMI; Kg/m2) to assess the prevalence of RC. The associations of measures of body composition with RA features - age, diagnosis time, Health Assessment Questionnaire (HAQ), Disease Activity Score in 28 joints (DAS 28), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) -, level of physical activity (measured by International Physical Activity Questionnaire – IPAQ) and current therapy were explored. Results: Mean age was 56,8 ± 7,3 , disease duration 9 years (3 – 18), DAS28 3,65 ± 1,32, HAQ 1,12 (0,25 – 1,87) and use duration of biological agents was 25 months (17,8 – 52,5). Seventeen per cent of the patients had FFMI below the 10th percentile and FMI above the 25th percentile of a reference population and 33% of the patients had FFMI below the 25th percentile and FMI above the 50th percentile, condition known as RC, according to the more recently used definitions. FFMI correlated negatively only with age (r=-0,219; p=0,037) and disease duration (rs=-0,214; p=0,042). FMI correlated positively with CRP (rs=0,229; p=0,029), ESR (rs=0,235; p=0,025), DAS 28 (rs=0,273; p=0,009) and HAQ (rs=0,297; p=0,004). Of the 26 patients using biological therapy, 25 were non cachetic (p=0,033) according to the stricter definition of RC. In another words, 3,8% (n=1) and 23% (n=15) of the patients receiving and not receiving biological agents had RC, respectively (p=0,033). Conclusion: The prevalence of RC was considerable and deserves additional research. Body composition, in this study, particularly FFMI is inversely associated with age and disease duration. Besides that, patients under biological therapy had lower prevalence of RC, suggesting a protective effect of biological agents.

Introdução: A artrite reumatoide é uma doença inflamatória autoimune associada à complicações sistêmicas como fadiga e perda muscular. Perda muscular pode estar relacionada com a ativação do sistema ubiquitina-proteossomo. O objetivo deste trabalho foi avaliar a perda muscular e o evolvimento do proteossomo no modelo de artrite induzida por colágeno (CIA), com ou sem o tratamento de metotrexato ou inibidor de TNF (etanercepte). Métodos: Camundongos DBA1/J machos foram divididos em 4 grupos (n=8 cada): CIA (salina); ETN (etanercepte, 5.5 /) e MTX (metotrexato, 35 /), tratados duas vezes por semana por 6 semanas, e um grupo controle saudável (CO). Tratamentos iniciaram uma semana após a injeção do booster. Escore clínico, edema da pata traseira e peso corporal foram analisados durante o período experimental. Músculo gastrocnêmio (GA) foi pesado após a morte e usado para quantificar a atividade, níveis proteicos e expressão de mRNA das diferentes subunidades do proteossomo através de ensaio fluorogênico, Western blot e rtPCR, respectivamente. Resultados: Tratamentos reduziram o desenvolvimento da doença, observado através do menor escore clínico e edema da pata traseira nos grupos ETN e MTX. ETN apresentou maior peso corporal do que MTX nas semanas 5 e 7. Músculo GA estava aumentado em ETN do que CIA e MTX, um resultado também observado no peso muscular normalizado. As propriedades catalíticas do proteossomo 26S muscular mostraram um aumento na atividade do tipo caspase nos grupos CIA e MTX. Tecidos musculares de animais MTX demonstraram maiores níveis proteicos das subunidades do proteossomo PSMB8 e PSMB9 e maior expressão gênica de Psmb5, Psmb8 e Psmb9. Por outro lado, a expressão de Psmb6 estava diminuída e de Psmb9 estava aumentada em CIA. Conclusões: Apesar de ambos os medicamentos melhorarem o escore da doença, ETN apresentou um afeito anti-artrítico mais forte e foi o único tratamento capaz de prevenir parcialmente a perda muscular. Ao contrário de ETN, CIA e o tratamento com MTX apresentaram perda muscular e atividade e expressão do proteossomo aumentadas. / Background: Rheumatoid arthritis is an autoimmune inflammatory disease associated with systemic complications like fatigue and muscle wasting. Muscle wasting could be related to the activation of the ubiquitin-proteasome system. The aim of this study was to evaluate muscle loss and involvement of the proteasome in collagen-induced arthritis (CIA), with or without treatment with methotrexate or a TNF inhibitor (etanercept). Methods: Male DBA1/J mice were divided into 4 groups (n=8 each): CIA (saline); ETN (etanercept, 5.5 /) and MTX (methotrexate, 35 /), treated twice a week for 6 weeks, and a healthy control group (CO). Treatments started one week after booster injection. Clinical score, hind paw oedema, and body weight were analysed during the experimental period. Gastrocnemius muscles (GA) were weighted after death and used to quantify proteasome activity, protein levels and mRNA expression of its subunits by Western blot and rtPCR, respectively. Results: Treatments slowed disease development, observed through smaller clinical score and hindpaw edema in ETN and MTX groups. ETN presented higher body weight compared to MTX group at weeks 5 and 7. GA weight was heavier in ETN than CIA and MTX, a result also observed in the normalized muscle weight. The catalytic properties of 26S proteasome showed an increase of caspase-like activity in CIA and MTX groups. Muscles tissues of MTX treated animals showed higher protein levels for proteasomal subunits PSMB8 and PSMB9 and higher gene expression for Psmb5, Psmb8 and Psmb9. In contrast, expression of Psmb6 was decreased and of Psmb9 was enhanced in CIA. Conclusions: Although both drugs improved the disease score, ETN presented a stronger anti-arthritic effect and was the only treatment able to partially prevent muscle wasting. In contrast to ETN, CIA and MTX treatment did not prevent muscles loss due to increased proteasome expression and activity.