Recomendações para rastreamento de Tuberculoses Latente (TBL) em pacientes que receberão tratamento com antagonistas do TNF-alfa (anti- TNF) permanecem controversas para regiões endêmicas Objetivo: Esse estudo buscou demonstrar a eficácia em longo prazo do rastreamento e tratamento da TBL em pacientes portadores de Artrite Reumatoide (AR) recebendo anti-TNF. Métodos: 202 pacientes com AR, antes do início do anti-TNF, foram rastreados para TBL por meio do teste tuberculínico (TT), Radiografia de tórax (RX) e história de prévia de exposição à tuberculose (EXP). Todos os pacientes foram seguidos com intervalos de um a três meses. Resultados: 85 pacientes (42%) foram tratados com um único agente anti-TNF e 117 pacientes (58%) mudaram de anti-TNF uma ou duas vezes. O rastreamento para TBL foi positivo em 66 pacientes, 44 apresentaram TT positivo, 23 apresentavam história de exposição (EXP), e 14, alterações radiográficas (RX). EXP isoladamente foi responsável por 14 diagnósticos em pacientes TT negativos. Pacientes portadores de TBL receberam tratamento com Isoniazida (300 mg/dia por seis meses) e nenhum deles desenvolveu TB. Durante os seguimentos, o TT foi repetido em 51 pacientes. A conversão foi observada em cinco: três foram diagnosticados com TBL e dois com TB ativa (14 e 36 meses após receber terapia anti-TNF), sugerindo nova exposição a TB. Conclusão: O rastreamento e tratamento da TBL antes do início da terapia com anti-TNF é efetiva em regiões endêmicas, e reforça a relevância da história de contato com TB para o diagnóstico da TBL em pacientes com AR / Recommendations for screening of latent tuberculosis infection (LTBI) in patients eligible for anti-TNF agents remain unclear in endemic regions. Objective: This study aimed to evaluate the long-term efficacy of LTBI screening/treatment in patients with rheumatoid arthritis (RA) receiving TNF blockers. Design: 202 RA patients were screened for LTBI prior to receiving anti-TNF treatment, by means of tuberculin skin test (TST), chest radiography (X-Ray), and history of tuberculosis exposure (EXP). All subjects were regularly followed at 1- to 3-month intervals. Results: Eighty-five patients (42%) were treated with a single anti-TNF agent, and 117 patients (58%) switched anti-TNF agents once or twice. LTBI screening was positive in 66 patients, 44 presented positive TST, 23 had a history of EXP, and 14, abnormal X-Ray. Exposure alone accounted for LTBI diagnosis in 14 patients with negative TSTs. LTBI patients were treated with Isoniazid (300 mg/day during six months) and none developed TB. During follow up, TST was repeated in 51 patients. Conversion was observed in five: three were diagnosed with LTBI and two with active TB (14 and 36 months after receiving anti-TNF therapy, suggesting new TB exposure). Conclusion: LTBI screening and treatment prior to anti-TNF treatment is effective in endemic areas and reinforces the relevance of contact history for diagnosing LTBI in RA patients

Introdução: A vacinação contra a influenza pandêmica A/H1N1 resultou em soroproteção em mais de 85% dos indivíduos saudáveis. Entretanto, dados em pacientes com artrite reumatoide (AR) são escassos. Objetivos: O objetivo deste estudo é avaliar a imunogenicidade e a segurança em curto prazo da vacina contra influenza pandêmica A/H1N1 em pacientes com AR e a influência da atividade da doença e da medicação nesta resposta. Métodos: Trezentos e quarenta pacientes adultos com AR em seguimento e tratamento regular e 234 controles saudáveis foram examinados antes e 21 dias após receber uma dose da vacina sem adjuvante contra influenza A/California/7/2009. A atividade da doença (DAS28), o tratamento em uso e os títulos de anticorpos também foram avaliados. As taxas de soroproteção (títulos de anticorpos >= 1:40) e soroconversão (percentagem de pacientes com aumento de título de anticorpos maior ou igual a 4, se o título pré- vacinal fosse maior ou igual a 1:10; ou título pós-vacinal de pelo menos 1:40, se o título pré-vacinal era menor que 1:10), as médias geométricas dos títulos (MGT) e o fator de incremento das médias geométricas (FI-MGT) foram calculados. Os eventos adversos foram também registrados. Resultados: Os pacientes com AR e os controles tinham taxas pré-vacinais de soroproteção (10,8% vs. 11,5%) e MGT (8,0 vs. 9,3) comparáveis (p>0,05). Após a vacinação, foi observada redução significativa na resposta dos pacientes com AR versus controles (p<0,001) em todos os desfechos sorológicos: taxas de soroproteção (60,0 vs. 82,9%) e soroconversão (53,2% vs. 76,9%), MGT (57,5 vs. 122,9) e FI-MGT (7,2 vs. 13,2). A atividade de doença não prejudicou a soroproteção ou a soroconversão e se manteve estável em 97,4% dos pacientes. O metotrexato e o abatacepte foram associados à redução da resposta vacinal. A vacinação foi bem tolerada, com poucos efeitos adversos. Conclusão: Os dados confirmaram tanto a segurança em curto prazo como, diferente da maioria dos trabalhos com influenza sazonal, a redução da soroproteção em pacientes com AR, não relacionada à atividade de doença e à maioria das medicações em uso (com exceção do metotrexato e do abatacepte). A extrapolação da resposta imunológica de uma vacina para outra pode não ser possível e estratégias específicas de imunização (possivelmente em duas doses) podem ser necessárias / Background: Pandemic influenza A/H1N1 vaccination yielded seroprotection in more than 85% of healthy individuals. However, similar data are scarce in rheumatoid arthritis (RA) patients. Objectives: The objective of this study is to evaluate the immunogenicity and the short-term safety of anti- pandemic influenza A/H1N1 vaccine in RA patients, and the influence of disease activity and medication to the response. Methods: Three hundred and forty adult RA patients in regular follow-up and treatment, and 234 healthy controls were assessed before and 21 days after adjuvant-free influenza A/California/7/2009 vaccine. Disease activity (DAS28), current treatment and anti-pandemic influenza A/H1N1 antibody titres were also evaluated. Seroprotection (antibody titre >=1:40) and seroconversion (the percentage of patients with a fourfold or greater increase in antibody titre, if prevaccination titre was 1:10 or greater, or a postvaccination titre of 1:40 or greater, if prevaccination titre was less than 1:10) rates, geometric mean titres (GMT) and factor increase in geometric mean titre (FI-GMT) were calculated and adverse events registered. Results: RA patients and controls showed similar (p>0.05) prevaccination seroprotection (10.8% vs. 11.5%) and GMT (8.0 vs. 9.3). After vaccination a significant reduction (p<0.001) was observed in all endpoints in RA patients versus controls: seroprotection (60.0 vs. 82.9%; p<0.0001) and seroconversion (53.2% vs. 76.9%) rates, GMT (57.5 vs. 122.9) and FI-GMT (7.2 vs. 13.2). Disease activity did not preclude seroprotection or seroconversion and remained unchanged in 97.4% of patients. Methotrexate and abatacept were associated with reduced responses. Vaccination was well tolerated with minimal adverse events. Conclusions: The data confirmed both short-term anti-pandemic A/H1N1 vaccine safety and, different from most studies with seasonal influenza, reduced seroprotection in RA patients, unrelated to disease activity and to most medications (except methotrexate and abatacept). Extrapolation of xii immune responses from one vaccine to another may therefore not be possible and specific immunization strategies (possibly booster) may be needed

Introdução: A pandemia de gripe A H1N1 em junho de 2009 resultou em elevadas taxas de hospitalização entre pacientes imunodeprimidos, incluindo pacientes com artrite idiopática juvenil (AIJ). Embora a vacinação seja uma medida eficaz contra complicações da gripe pandêmica, não há estudos na literatura sobre seus efeitos na AIJ. Objetivos: Avaliar a resposta resposta da vacina contra influenza A H1N1/2009 sem adjuvante na AIJ, como uma extensão do estudo anterior de imunogenicidade e segurança em uma grande população de pacientes com doenças reumáticas juvenis. Além disso, avaliar a possível influência de dados demográficos, subtipos de AIJ, atividade da doença e do tratamento sobre a imunogenicidade e o potencial efeito deletério da vacina sobre a doença, particularmente sobre o número de articulações ativas e os marcadores inflamatórios. Métodos: 95 pacientes com AIJ e 91 controles saudáveis foram avaliados antes e 21 dias após a vacinação contra influenza A H1N1/2009 e a sorologia anti-H1N1 foi realizada por ensaio de inibição de hemaglutinação. A avaliação global de atividade da artrite por uma escala visual analógica (EVA) pelo paciente e pelo médico, o Childhood Health Assessment Questionnaire (CHAQ), o número de articulações ativas, as provas de fase aguda (VHS e PCR) e o tratamento foram avaliados antes e após a vacinação. Os eventos adversos foram também reportados. Resultados: Pacientes com AIJ e controles foram comparáveis em relação à média de idade atual (14,9 ± 3,2 vs. 14,6 ± 3,7 anos, p=0,182). A taxa de soroconversão após a vacinação foi significantemente menor nos pacientes com AIJ em relação aos controles (83,2% vs. 95,6%, p=0,008), particularmente no subtipo poliarticular (80% vs. 95,6%, p=0,0098). Os subtipos de AIJ, o número de articulações ativas, as provas de fase aguda, a EVA do paciente e do médico, o CHAQ e a frequencia de uso de DMARDs/imunossupressores foram semelhantes entre os pacientes que soroconverteram versus os que não soroconverteram (p>0,05). Em relação à segurança da vacina, não foi observada piora no número de articulações ativas e nas provas de fase aguda durante o período de estudo. Conclusão: A vacinação contra influenza A H1N1/2009 na AIJ induziu uma resposta humoral reduzida com adequado efeito protetor, independente de parâmetros da doença e tratamento, e com um perfil adequado de segurança da doença. / Introduction: The influenza H1N1 pandemic in June 2009 resulted in high hospitalization rates among immunocompromised patients, including patients with juvenile idiopathic arthritis (JIA). Although vaccination is an effective tool against pandemic flu complications, there are no studies in the literature on its effects in JIA. Objectives: To assess the immune response against the influenza A H1N1/2009 vaccine without adjuvant in JIA as an extension of previous observation of its immunogenicity and safety in a large population of patients with juvenile rheumatic diseases. Moreover to assess the possible influence of demographic data, subtypes of JIA, disease activity and treatment on the immunogenicity and the potential deleterious effect of vaccine on disease itself, particularly on the number of active joints and inflammatory markers. Methods: 95 JIA patients and 91 healthy controls were evaluated before and 21 days after vaccination against influenza A and serology for anti-H1N1 was performed by hemagglutination inhibition assay. The overall assessment of arthritis activity by a visual analogue scale (VAS) by patient and physician, the Childhood Health Assessment Questionnaire (CHAQ), the number of active joints, the acute phase reactants (ESR and CRP) and treatment were evaluated before and after vaccination. Adverse events were also reported. Results: JIA patients and controls were comparable regarding mean current age (14.9 ± 3.2 vs. 14.6 ± 3.7 years, p=0.182). After vaccination seroconversion rate was significantly lower in JIA patients compared to controls (83.2% vs. 95.6%, p=0.008), particularly in polyarticular subtype (80% vs. 95.6%, p=0.0098). JIA subtypes, number of active joints, acute phase reactants, patient and the physician VAS, CHAQ and frequency of use of DMARDs/Immunosuppressants were similar between patients with and without seroconversion (p>0.05). Regarding vaccine safety, no deterioration was observed in the number of active joints and the acute phase reactants during the study period. Conclusion: Influenza A H1N1/2009 vaccination in JIA induces a lower but effective antibody response, probably independent of disease parameters and treatment with an adequate disease safety profile.

Para avaliar a fagocitose de células da série monócitos-macrófagos de cabras naturalmente infectadas pelo vírus da artrite encefalite caprina a vírus (VAEC), 30 cabras da raça Saanen foram utilizadas e alocadas em dois grupos distintos, sendo um grupo formado por 15 animais soropositivos à imunodifusão em gel de ágar para detecção de anticorpos séricos antivírus da AEC e o outro formado por 15 animais soronegativos ao teste. Células mononucleares de sangue periférico foram isoladas por gradiente de concentração e plaqueadas em placas de poliestireno para isolamento de células da série monócito-macrófago. Após adesão das mesmas, adicionou-se a bactéria Corynebacterium pseudotuberculosis como desafio antigênico. Dois tipos de fagocitose foram observados em relação ao número de bactérias internalizadas nos vacúolos citoplasmáticos dos macrófagos, isto é, verificou-se a presença de células fagocitando em média 12 bactérias e outro grupo fagocitando um número incontável de bactérias. Dessa forma, classificou-se a fagocitose em fagocitose + (até 12 bactérias) e fagocitose ++ (mais de 12 bactérias). Em relação à fagocitose total (fagocitose + e fagocitose ++) não foram verificadas diferenças estatística significativas entre os grupos experimentais (p < 0,41). Todavia, ao discriminar a fagocitose conforme a quantificação de bactérias fagocitadas, encontrou-se diferença estatística entre os grupos, sendo que o grupo positivo apresentou maior porcentagem de fagocitose ++ (p < 0,001). O grupo negativo apresentou maior porcentagem de fagocitose + (p < 0,012). Correlação positiva entre monócitos fagocitando e fagocitose ++ foi observada no grupo de animais soropositivos (p < 0,006), porém, não foi observada nenhuma correlação no grupo negativo (p < 0,49). Esses resultados demonstram uma possível alteração na intensidade da fagocitose de macrófagos de animais infectados com o VAEC, sugerindo que os animais com artrite encefalite caprina estejam mais susceptíveis à linfadenite caseosa. / To evaluate the phagocytosis from monocyte-macrophage line cells 30 naturally infected Saanen goats with caprine arthritis-encephalitis vírus (VCAE) were used, and divided uniformly in different groups according to agar gel immunodiffusion test (AGID). Peripheral Blood Mononuclear Cell (PBMC) was isolated by density gradient centrifugation. The monocyte-macrophage cells were separated from PBMC by their adherence properties. Afterwards, the phagocytosis function was assessed by phagocytosis assay using Corynebacterium psudotuberculosis as a source of antigen. Therefore, two distinct types of phagocytosis were observed and were set according to the number of bacteria within the cytoplasmatic vacuoles. Thus, the phagocytosis rates were also divided in two groups, on the first was observed up to 12 bacteria in the vacuoles; on the other hand in the second group an uncountable number of bacteria were usually seen. Consequently, the phagocytosis rates were also divided in phagocytosis + (up to 12 bacteria) and phagocytosis ++ (more than 12 bacteria). The results from the phagocytosis rates show any difference, however when the phagocytosis rates were separated in the order of the number of Corynebacterium pseudotuberculosis phagocyted, the phagocytosis ++ from positive animals in the sera test were higher than the negative one (p < 0.001). Nevertheless, the negative group presents higher pahgocytosis + (p < 0.012). Furthermore a positive and significant correlation between phagocytosis ++ and monocyte phagocytosis (p < 0.006) were also encountered in the positive animals, however the same were not observed in the negative group (p < 0.49). In face of, the results from the present trial point out to higher susceptibility to caseous linphadenitis in goats infected with VCAE due to the alteration on the phagocytosis strength in these animals.

Introdução: Dor e deformidade nos pés são queixas comuns na Artrite Reumatóide (AR) promovendo alterações no equilíbrio e na mobilidade funcional. A informação somatossensorial dos pés e tornozelos para a regulação da postura e manutenção do equilíbrio tem sido discutida na literatura e apregoa-se que a integridade do pé e da sua informação sensorial são fundamentais para a estabilidade postural. Os programas propostos neste trabalho para estes pacientes integram atenção para a dor e para as deformidades enfocando a melhora da funcionalidade. Objetivos: (i) Verificar os efeitos de um programa progressivo de exercícios de reabilitação funcional e orientação de auto cuidado na dor, no equilíbrio e na mobilidade funcional em portadores de AR, personalizado segundo a necessidade e evolução do paciente, administrado individualmente; (ii) verificar os efeitos de um programa progressivo de exercícios de reabilitação funcional e orientação de auto cuidado na dor, no equilíbrio e na mobilidade funcional em portadores de AR, programa este pré-estabelecido, não personalizado, e administrado em grupo, e: (iii) comparar a eficiência dos dois programas em relação a um grupo controle. Métodos: 5 homens e 40 mulheres portadores de AR com dor e deformidade nos pés foram divididos em 3 grupos segundo ordem de encaminhamento para a fisioterapia: G1- grupo que recebeu o programa progressivo personalizado, G2- grupo controle, e G3- grupo que recebeu o programa progressivo préestabelecido . Todos os pacientes foram avaliados para dor (Escala Numérica de Dor - NRS), saúde dos pés (Questionário Condição de Saúde dos pés FHSQ-Br), equilíbrio (Escala de Berg Balance Berg e Teste de Alcance Funcional TAF) e mobilidade funcional (Teste de Timed Up & Go TUG) ao ingressar no estudo (A1) e após 30 dias (A2), ao completar o programa ou o período controle. O programa de exercícios do G1 foi administrado individualmente e sua progressão seguia o critério de necessidade e evolução do paciente. O programa de exercícios do G3 foi administrado em grupo e sua progressão foi pré-estabelecida em 4 etapas utilizando-se de 4 cartilhas de apoio. Os dois programas foram aplicados duas vezes por semana, durante um período de 30 dias, e eram constituídos de atenção para auto cuidado nos pés, treinamento de equilíbrio e de atividades funcionais. Resultados: Por ocasião do ingresso no estudo (A1) todos os pacientes eram semelhantes em todas as variáveis analisadas, com exceção do teste TUG, que apresentou diferença estatística entre G2 x G1 e G2 x G3 (p< 0,005). Quando analisados os grupos isoladamente, a comparação de A1 e A2 no programa progressivo personalizado - G1, apresentou melhora significativa na NRS (p= 0,002), Berg (p= 0,002), TAF (p= 0,008) e na mobilidade funcional - TUG (p= 0,001). Nos benefícios percebidos FHSQ-Br, apresentou melhora significante no domínio de dor (p=0,015), sapatos (p= 0,012), índice de saúde dos pés (p=0,039) e vigor (p=0,054). A comparação de A1 e A2 no grupo controle - G2, não foi observada diferença significativa em todas as variáveis estudadas. A comparação de A1 e A2 no programa progressivo pré-estabelecido - G3, apresentou melhora significativa no NRS (0,012), Berg (0,002), nos benefícios percebidos sob a dor nos pés (p= 0,013), função dos pés (p= 0,005), saúde geral dos pés (p= 0,001), índice de saúde geral dos pés (p= 0,004), atividade física (p= 0,014), capacidade social (p= 0,001) e índice de saúde (p= 0,015). Comparando-se os três grupos, o G1 apresenta melhora no teste TUG (p=0,001) quando comparado com G2 e G3, no NRS (0,001) quando comparado com G2, enquanto que o G3 apresenta melhora na saúde geral dos pés quando comparado com G1 (p=0,056) e G2 (p=0,037). Conclusão: O programa progressivo personalizado promoveu melhora da dor, do equilíbrio e da mobilidade funcional em portadores de AR além de 4 dos domínios do FHSQBR (dor nos pés, sapatos, índice de saúde dos pés e vigor). O programa progressivo pré-estabelecido promoveu a melhora da dor, do equilíbrio e dos benefícios percebidos em portadores de AR e em 8 domínios do FHSQ-BR (dor nos pés, função dos pés, saúde geral dos pés, índice de saúde geral dos pés, atividade física, capacidade social, índice de saúde). Comparando os programas, G1 apresentou melhora da mobilidade funcional e G3 apresentou melhora no benefício percebido em saúde geral dos pés. / Background: Rheumatoid arthritis (RA) is a common systemic disease in which foot involvement has been largely claimed. A functional foot must reveal musculoskeletal integrity such as joint alignment and range of motion, mobility and muscular strength. It is essential for postural and balance control as well as effective propulsion during gait. Impairment of foot somatosensory information leads to postural instability, and produce a severe negative impact on mobility and functional capacity. Plantar sensitivity is also decreased in patients with RA, reinforcing that RA patients show deficits in balance and functional activities as a result of alterations on foot functioning. Objective: To verify comparatively the effects of graded exercise, personalized or pre-established, for functional rehabilitation programs on pain, balance and mobility in patients with rheumatoid arthritis (RA). Methods: 5 male and 40 female patients with RA, pain and foot deformity were sequentially allocated into three groups: G1- personalized program, G2- control group, and G3- pre-established program All patients were assessed in the beginning the study (A1) and after 30 days (A2), for pain (Numerical Rating Scale - NRS), perceived benefits (Foot Health Status Questionnaire - FHSQ-Br), balance (Berg Balance Scale - Berg, Functional Reach - FR) and functional mobility (Timed Up & Go - TUG). G1 and G3 underwent functional rehabilitation program for 30 days. The program comprised of graded exercises and self-care guidance for functional rehabilitation and were applied on two weekly sessions of 60 minutes each, during 4 weeks. Results: Analysis of A1 revealed no significant difference for all variables in the three groups, except for TUG test. Comparing G2 x G1 and G2 x G3 patients from control group, G2, needed shorter time to the completion of the test when compared to G1 and G3. Comparison from to A1 and A2 in G1, revealed significant improvement in NRS, Berg, FR, and in TUG. FHSQ-Br showed significant improvement in the domain of pain, shoes, foot health index, and vigour. Comparison of A1 and A2 in the G3, showed significant improvement in NRS, Berg, and in the domains of pain, function, general foot health, general foot health index, physical activity, social capability, and general health index for FHSQ-Br. Variation from A1 to A2 in G2 revealed no significant difference. Comparing the three groups, G1 showed improvement in TUG, compared to G2 and G3, in NRS compared with G2, whereas G3 revealed improvement in the observed benefit in general foot health compared to G1 and G2. Conclusion: Both programs revealed benefits for patients with RA. In the personalized graded exercises, utmost improvements were found mainly in the objective variables, pain, balance, and functional mobility, beyond 4 out of 10 FHSQ-Br domains whereas in the pre-established graded exercise, in the perceived benefit, 8 out of 10 FHSQ-Br domains beyond pain and balance. domains whereas in the pre-established graded exercise, in the perceived benefit, 8 out of 10 FHSQ-Br domains beyond pain and balance.

Abstract Rheumatoid arthritis and osteoarthritis are two chronic joint diseases, which cause two of the largest socioeconomical burdens among all joint diseases according to the World Health Organization. Both diseases are associated with changes in bone structure and bone cell, especially osteoclast, function. The etiology or pathogenesis of these diseases are not completely understood. Traditionally, osteoarthritis is seen as a disease resulting from mechanical wear of cartilage and bone, and rheumatoid arthritis as an autoinflammatory disease of synovial tissue. However, also in osteoarthritis chronic inflammation is present in synovial tissue, and in rheumatoid arthritis large changes in bone structure are seen. The field of study focusing on this connection between inflammation and bone is called osteoimmunology and it can explain many features of these chronic diseases linking joint health to disturbances in bone homeostasis. Here, the study focused on the function of osteoclasts in normal and pathological environments, and on the factors that have an effect on bone resorption, with a special emphasis on the protein osteopontin. Samples of synovial fluid and serum from rheumatoid arthritis and osteoarthritis patients were analyzed for factors affecting osteoclasts, and in vitro cell cultures of human derived osteoclasts were used to analyze osteoclast function in normal and pathological environment. The phosphorylation of osteopontin was found to be increased in rheumatoid arthritis, along with multiple other inflammatory factors that also affect osteoclasts, such as IL-6, IL-8 and VEGF. Osteoclast cell cultures showed how the use of different patient samples significantly affected osteoclastogenesis, due to so-called inflammatory osteoclastogenesis. Additionally, we show that osteoclasts deposit osteopontin into the resorption lacunae during bone resorption. Based on the results, the inflammatory component present in both osteoarthritis and rheumatoid arthritis significantly affects osteoclast function, and its further study in the future may reveal new therapeutic possibilities. Especially the new discoveries of osteopontin’s role in normal osteoclast function and its changes seen between osteoarthritis and rheumatoid arthritis may prove to have therapeutic potential. / Tiivistelmä Nivelreuma ja nivelrikko ovat kroonisia nivelsairauksia, jotka Maailman terveysjärjestön (WHO) mukaan aiheuttavat eniten sosioekonomista haittaa. Molemmissa sairauksissa luiden rakenteessa ja luusolujen, erityisesti osteoklastien, toiminnassa tapahtuu muutoksia. Kummankaan taudin etiologiaa tai patogeneesiä ei täysin tunneta. Perinteisesti ajatellaan, että nivelrikko johtuu rusto- ja luukudoksen mekaanisesta kulumisesta ja nivelreuma nivelkalvon autoinflammatoorisesta tulehduksesta. Kuitenkin nivelrikossa nähdään myös selkeä nivelkalvon krooninen tulehdus ja nivelreumassa suuria luun rakenteen muutoksia. Tutkimusala, joka tutkii tulehduksen ja luun yhteyttä, on nimeltään osteoimmunologia. Tässä väitöskirjassa tutkitaan osteoklastien toimintaa ja niihin vaikuttavia tekijöitä, erityisesti proteiini osteopontiinia, normaalissa ja tautiympäristössä. Analysoin osteoklasteihin vaikuttavia tekijöitä nivelrikko- ja nivelreumapotilaiden näytteistä sekä osteoklastien toimintaa soluviljelmissä. Soluviljelmissä käytettiin nivelreuma- ja nivelrikkopotilaiden näytteitä mahdollisimman totuudenmukaisen ympäristön luomiseksi osteoklasteille. Tutkimuksessa osoitettiin, kuinka osteopontiinin fosforylaatio on lisääntynyt nivelreumapotilaiden nivelnesteessä. Myös useiden muiden osteoklasteihin vaikuttavien tekijöiden, kuten IL-6:n, IL-8:n ja VEGF:n, havaittiin lisääntyneen nivelreumassa. Osteoklastien soluviljelmissä havaittiin selkeät erot siinä, miten eri potilasnäytteet vaikuttavat osteoklasteihin ja erityisesti tulehduksen aiheuttamaan osteoklastien syntyyn. Osoitan myös, miten osteoklastit erittävät osteopontiinia luunhajotuskuoppaan luun hajotuksen aikana. Tutkimustulosten mukaan krooninen tulehdustila nivelrikossa ja nivelreumassa vaikuttaa huomattavasti osteoklastien toimintaan. Uskon, että lisätutkimukset tällä saralla voivat paljastaa uusia hoidollisia mahdollisuuksia. Erityisesti uudet löydökset osteopontiinin roolista osteoklastien toiminnassa sekä muutoksista nivelrikossa ja nivelreumassa vaativat jatkotutkimuksia, jotta proteiinin kliininen merkittävyys saadaan selvitettyä.

En vue de contribuer à une meilleure compréhension des atteintes du système musculo-squelettique consécutives à une infection par un arthropod-borne-virus (arbovirus), deux arbovirus ont été étudiés : le virus du chikungunya (CHIKV) et le virus Zika (ZIKV), respectivement de la famille des Togaviridae et des Flaviviridae. Cette étude a été réalisée selon deux axes. Le premier s’intéresse aux atteintes articulaires consécutives à l’infection par le CHIKV. Nous avons mis au point un modèle d’imagerie in vivo reposant sur l’utilisation d’un virus recombinant exprimant la NanoLuciférase. Dans ce modèle, nous démontrons une persistance du signal bioluminescent dans les articulations 34 jours après infection. Par isolement des cartilages articulaires et des cellules constitutives, nous avons pu démontrer que les chondrocytes des cartilages métatarso-phalangiens sont infectés par le CHIKV de manière persistante, suggérant un rôle de réservoir de ces cellules. Les conséquences de l’infection au niveau cellulaire ont ensuite été étudiées in vitro. En utilisant des chondrocytes primaires humains, nous avons confirmé ces observations. De plus, les chondrocytes infectés produisent de nombreuses cytokines, induisant une stimulation du catabolisme du cartilage avec en particulier la synthèse de métalloprotéinases de matrice 3 et 9. De plus, l’infection par le CHIKV provoque la mort des cellules par apoptose, comme démontré par marquage TUNEL et par mesure de l’activité des caspases. Nous avons ensuite étudié les atteintes musculaires et le tropisme cellulaire du ZIKV. Dans un modèle murin, nous avons confirmé la présence de lésions musculaires, et l’utilisation de cellules musculaires primaires humaines a montré la sensibilité des myoblastes à l’infection, les myotubes étant résistants, suggérant un tropisme du ZIKV dépendant de la différenciation cellulaire. Trois souches virales ont été testées, sans relever de différences significatives en termes de cinétique d’infection, de nombre de cellules infectées et de production virale. L’infection des myoblastes entraîne la mort de ces cellules par un mécanisme caspase-indépendant. Des observations en microscopie électronique ont mis en évidence une vacuolisation du cytoplasme suite à l’infection, caractéristique d’une mort cellulaire par paraptose. Une analyse protéomique a démontré que l’infection des myoblastes par une souche asiatique conduit à une modification du protéome s’accentuant entre 24 heures et 48 heures post-infection, avec 225 protéines modulées 24 heures après infection contre 473 après 48 heures, indiquant une activation des voies de synthèse Interferon de type I et l’inhibition des capacités de synthèse des protéines. Ces résultats permettent une meilleure compréhension des atteintes du système-musculo-squelettique par les arbovirus / Musculoskeletal lesions caused by arthropod-borne-viruses (arboviruses) are invalidating for patients and remain poorly understood. In this study, we investigated the development of these manifestations after infection with two arboviruses: chikungunya virus (CHIKV) from the Togaviridae family, and Zika virus (ZIKV) from the Flaviviridae family. The first part of the study focused on arthritis following CHIKV infection. For this purpose, we developed a reporter virus expressing NanoLuciferase and performed experimental infections in a murine model. In vivo, a strong bioluminescent signal indicated viral replication and we observed persistence of the signal in the joints up to 34 days post-infection. By isolating primary murine cells from cartilage, we demonstrated the susceptibility of chondrocytes to CHIKV infection suggesting a role of reservoir of these cells. Furthermore, we investigated the consequences of the infection using in vitro models. We showed that primary human chondrocytes are also susceptible to CHIKV infection, which leads to the production of several cytokines involved in cartilage catabolism and induces apoptosis. In the second part of the study, we studied ZIKV muscular tropism and the associated lesions. Firstly, we confirmed the development of muscular lesions in a mouse model of ZIKA. Then, using human primary muscle cells we observed the infection of myoblasts but not myotubes, suggesting a differentiation-dependent tropism. We compared three viral strains and observed no significant difference in terms of replication, number of infected cells and viral production. Myoblasts infection induced a caspase-independent cells death mechanism and electronic microscope observations revealed intense vacuolization of cytoplasm, suggesting a paraptosis-like cell death. Proteomic analysis revealed that the Asian ZIKV strain modulated protein expression of infected cells with an increased effect after 48 hours. ZIKV-infection induced an important upregulation of biological processes associated with type I interferon and an inhibition of protein synthesis in the infected cells. These results provide valuable information about the mechanisms involved in the development of musculoskeletal lesions during arboviroses

Includes list of publications arising from this thesis / Erratum attached to inside back cover. / "25/03/2004." / Includes bibliographical references (leaves 185-257) / xii, 257 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine and Royal Adelaide Hospital, Rheumatology Unit, 2004

<p>This thesis describes stereoselective syntheses of four amino acids, three of which are C-glycosidic analogues of glycosylated amino acids. The overall goal of the project was to probe the interactions between MHC molecules, glycopeptide antigens and T cell receptors, that are essential for development of collagen induced arthritis. Collagen induced arthritis is a frequently used mouse model for rheumatoid arthritis, an autoimmune disease that attacks joint cartilage and leads to a painful and eventually crippling condition.</p><p>The thesis is based on four studies. The first study describes the synthesis of hydroxylysine, an amino acid that is found in collagen and is an important constituent of the glycopeptide proposed as an antigen in collagen induced arthritis. During the synthesis of hydroxylysine some new insight into the mechanism of the reductive opening of <i>p</i>-methoxybenzylidene acetals was obtained.</p><p>The remaining three studies deals with the synthesis of C-glycosidic analogues of glycosylated amino acids, hydroxy norvaline, threonine and hydroxylysine.The synthesis of each amino acid required control of several stereogenic centra and utilizes a variety of approaches such as use of stereoselective reactions, chiral auxilaries, chiral templates and asymmetric catalysis.</p><p>The C-glycosidic analogues of galactosylated hydroxynorvaline and hydroxylysine were incorporated in glycopeptides from type II collagen and evaluated in T cell response assays. It was found that the T cells were stimulated by the C-glycopeptides, but that higher concentrations were required than for the native O-glycopeptide</p>

<p>Rheumatoid arthritis (RA) is an autoimmune disease affecting approximately 1% of the population in the western world. It is characterised by a tissue specific attack of cartilage in peripheral joints. Collagen induced arthritis (CIA) is one of the most commonly used animal models for (RA), with similar symptoms and histopathology. CIA is induced by immunisation of mice with type II collagen (CII), and the immunodominant part was previously found to be located between residues 256-270. This thesis describes the interaction between the MHC molecule, glycopeptide antigens from CII and the T cells that is essential in development of CIA. The glycopeptide properties for binding to the mouse MHC molecule Aq have been studied, as well as interaction points in the glycopeptide that are critical for stimulation of a T-cell response.</p><p>The thesis is based on five studies. In the first paper the minimal glycopeptide core, that is required for binding to the Aq molecule while still giving a full T cell response was determined. The second paper studied the roles of amino acid side-chains and a backbone amide bond as T-cell contact points. In the third paper the hydrogen bond donor-acceptor characteristics of the 4-OH galactose hydroxyl group of the glycopeptide was studied in detail. In the fourth paper we established a structure activity relationship (QSAR model) for (glyco)peptide binding to the Aq molecule. Finally, the stereochemical requirements for glycopeptide binding to the Aq molecule and for T-cell recognition was studied in the fifth paper.</p><p>The study was performed using collagen glycopeptide analogues, which were synthesised on solid phase. Amide bond and hydroxyl group isosteres were introduced for study of hydrogen bond donor-acceptor characteristics. Statistical methods were used to design a representative peptide test set and in establishing a QSAR model.</p><p>The results give a deeper understanding of the interactions involved in the ternary MHC-glycopeptide-T cell complex. This information contributes to research directed towards finding new treatments for RA.</p>