Submitted by Carla Ferreira (carlaferreira66@gmail.com) on 2014-07-31T12:23:26Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) HerminioSobrinho-2008 (1).PDF: 811492 bytes, checksum: 63a0aabcbb6458adb1051bc054066d08 (MD5) / Made available in DSpace on 2014-07-31T12:23:26Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) HerminioSobrinho-2008 (1).PDF: 811492 bytes, checksum: 63a0aabcbb6458adb1051bc054066d08 (MD5) Previous issue date: 2008 / Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE) are autoimmune diseases of unknown etiology. Some species of mycoplasmas cause arthritis in animals and humans, and their lipid-associated membrane proteins (LAMPs) and Mycoplasma arthritidis mitogen (MAM superantigen) are potent stimulators of the immune system. Thus, it has been proposed that mycoplasma can be involved in autoimmune-disease etiology. The objective of the present work was to detect antibodies to MAM and LAMPs of M. hominis and M. fermentans in the patient sera, and to characterize the profile of IgG antibodies reactivity with LAMPs in order to identify the major immunogenic mycoplasmal lipoproteins that could be involved in the etiopathogenesis of these autoimmune diseases. Serum samples were obtained from peripheral blood of female patients at the same age of healthy controls. Recombinant MAM (from M. arthrititidis), LAMPs of M. hominis PG21 and M. fermentans PG18 were used in Western blotting assays. Antibodies to MAM were detected in the patient and control sera (RA: 27.5% vs 18.8%; SLE: 21.7% vs 20.0%). At least 23 LAMPs were found in the preparations of M. hominis PG21 and of M. fermentans PG18 with molecular masses between 20 and 192 KDa. The sera of RA patients recognized a larger number of LAMPs of M. hominis PG21 and M. fermentans PG18 than the control sera (RA: 11 ± 4 vs controls: 7 ± 3, n = 35; p < 0,05). Most of the sera of RA patients presented strong reactivity with LAMPs of M. hominis PG21 (RA: 65.7% vs controls: 20%, p < 0.05). LAMPs of M. hominis PG21 with molecular masses < 49 and ? 20 KDa and LAMPs of M. fermentans PG18 < 102 and ? 58 were mainly recognized by IgG antibodies of RA patients. When comparing sera from SLE patients and controls there was detected no significant differences between the profiles of IgG reactivity. Therefore, M. hominis PG21 LAMPs (< 49 and ? 20 KDa) and M. fermentans PG18 LAMPs (< 102 and ? 58 KDa) are high immunogenic mycoplasmal antigens that can induce antibody cross reactivity with self antigen, contributing with the RA pathogenesis. / A artrite reumatóide (AR) e o lúpus eritematoso sistêmico (LES) são doenças autoimunes de etiologia desconhecida. Algumas espécies de micoplasmas causam artrite séptica em seres humanos, sendo estas bactérias fortes candidatos à etiopatogênese destas doenças. O superantígeno MAM é uma proteína secretada por Mycoplasma arthritidis, que juntamente com lipoproteínas (LAMPs) de M. hominis e M. fermentans, ativam as células do sistema imune e podem estar envolvidos na etiopatogenia da AR e do LES. O objetivo do presente trabalho foi detectar e caracterizar a resposta de anticorpos IgG contra superantígeno MAM e LAMPs de M. fermentans e M. hominis em soros de pacientes com AR ou LES, a fim de detectar as LAMPs mais imunogênicas candidatas a antígenos envolvidos na etiopatogenia destas doenças. Os pacientes com AR ou LES e os controles saudáveis eram indivíduos do sexo feminino e da mesma faixa etária. Foi usado MAM recombinante e LAMPs de M. hominis PG21 e M. fermentans PG18 extraídas com detergente Triton X-114, para avaliar o perfil de anticorpos IgG por meio da técnica de Western blotting. Anticorpos IgG anti-MAM foram detectados tanto nos soros de pacientes quanto nos dos controles (AR: 27,5% vs 18,8%; LES: 21,7% vs 20,0%). Foram detectadas pelo menos 23 LAMPs nas preparações de M. hominis PG21 e de M. fermentans PG18 com massas moleculares entre 20 e 192 KDa. Os soros de pacientes com AR reconheceram um maior número de LAMPs de M. hominis PG21 e de M. fermentans PG18 do que os soros controles (AR: 11 ± 4 vs controles: 7 ± 3, n = 35; p < 0,05). A maioria dos soros dos pacientes com AR apresentou forte reatividade com LAMPs de M. hominis PG21 (AR: 65,7% vs controles: 20%, p < 0,05). As LAMPs de M. hominis PG21 com massas moleculares <49 e ³ 20 KDa e de M. fermentans PG18 < 102 e ? 58 foram mais frequentemente reconhecidas por anticorpos IgG de soros de pacientes com AR do que por anticorpos dos soros controles. Não foram atestadas diferenças significantes entre os perfis de reatividade dos soros de pacientes com LES e controles, nem com relação ao número de LAMPs reconhecidas, nem com as diferentes faixas de massas moleculares das LAMPs. Portanto, as LAMPs de M. hominis (<49 e ³ 20 KDa) e M. fermentans (< 102 e ? 58) podem ser antígenos que induzem a produção de anticorpos que reagem cruzadamente com antígenos próprios, contribuindo para o processo da patogênese da AR.

Objetivos: Os objetivos deste estudo foram: avaliar a frequência de imunodeficiências primárias de anticorpos e Complemento em pacientes com lupus eritematoso sistêmico juvenil (LESJ); avaliar possíveis associações entre a presença de imunodeficiência primária (IDP) e dados demográficos, ocorrência de infecções, manifestações clínicas, atividade da doença, dano cumulativo e terapêutica direcionada ao LESJ; e determinar a frequência do anticorpo anti-C1q, estabelecendo a sua especificidade, sensibilidade e valores preditivos para o diagnóstico de LESJ. Métodos: Setenta e dois pacientes com LESJ foram avaliados para a determinação dos níveis séricos de imunoglobulinas (IgG, IgA, IgM e IgE) e subclasses de IgG, e dos componentes iniciais da via clássica do sistema Complemento (C1q, C1r, C1s, C4, C2, C3). Sessenta e sete pacientes e 26 controles saudáveis foram avaliados para a presença do anticorpo anti-C1q. O número de cópias do gene C4 foi determinado por PCR (reação de polimerase em cadeia) em tempo real nos pacientes com deficiência de C4. Setenta pacientes foram avaliados para a presença de deficiência de C2 tipo I. Resultados: Evidência de IDP foi identificada em 16 pacientes (22%): 3 com deficiência (D) de C2, 3 com C4D, 2 com C1qD, 4 com IgG2D (<20mg/dL), 3 com IgAD (<7mg/dL), e 3 com IgMD (<35mg/dL); um destes pacientes apresentou deficiência concomitante de IgA, C4 e C2. Quatro dos 13 pacientes do sexo masculino (30%) e 12 das 59 pacientes do sexo feminino (20%) apresentaram diagnóstico de IDP. As características clínicas de LES não diferiram entre os pacientes com e sem IDP. A mediana do SLICC/ACR-DI foi maior entre os pacientes com IDP (p=0,0033), assim como a frequência de SLICC/ACR-DI>1 (p=0,023). Os grupos também foram semelhantes quanto à ocorrência de infecção e terapêutica utilizada para o LESJ. Os únicos dois casos de LESJ com idade de início antes dos 2 anos apresentaram C1qD e IgMD, respectivamente. Para o diagnóstico de LESJ, o anticorpo anti-C1q apresentou especificidade de 100% (IC 86.7-100%), sensibilidade de 19.4% (IC 10.7-30.8%), valor preditivo positivo de 100% (IC 75.3-100%) e valor preditivo negativo de 32,5% (IC 22,4-43,9%). Conclusões: Foi observada uma elevada frequência de imunodeficiências de anticorpos e Complemento nos pacientes com LESJ, sugerindo que esses defeitos podem contribuir para a patogênese do lúpus. Esses achados indicam que os dois grupos de IDPs devem ser investigados em pacientes com LES de início precoce e de maior gravidade / Objectives. The objectives of this study were: to establish the frequency of primary immunoglobulin and Complement deficiency in Juvenile SLE (JSLE); to evaluate possible associations between the presence of primary immunodeficiency and demographic data, occurrence of infections, JSLE clinical manifestations, disease activity, cumulative damage and therapy; and to determine the frequency of anti-C1q antibody, establishing its sensitivity, specificity and predictive values for JSLE diagnosis. Methods. Seventy-two JSLE patients were analyzed for serum levels of immunoglobulin classes (IgG, IgA, IgM e IgE) and IgG subclasses and early components of the classical Complement pathway (C1q, C1r, C1s, C4, C2, C3). Sixty-seven patients and 26 healthy controls were evaluated for the presence of anti-C1q antibody. C4 gene copy number was determined by real time PCR (polymerase chain reaction) in C4 deficient patients. Seventy patients were analyzed by PCR for the presence of type I C2 deficiency. Results. Evidence of PID was identified in 16 patients (22%): 3 with C2 deficiency (D), 3 with C4D, 2 with C1qD, 4 with IgG2D (<20mg/dL), 3 with IgAD (<7mg/dL), and 3 with IgMD (<35mg/dL); one of these patients presented concomitant IgA, C2 and C4 deficiency. Four out of the 13 boys (30%) and 12 out of 59 girls (20%) had PID diagnosis. SLE features did not differ between patients with and without PID. The median SLICC/ACR-DI was higher among PID subjects (p=0.0033), as was the frequency of SLICC/ACR-DI>1 (p=0.023). Both groups did not differ regarding the occurrence of infections and therapeutic for JSLE. The only 2 cases with age of onset below 2 years presented C1qD and IgMD, respectively. For JSLE diagnosis, the anti-C1q antibodies presented a specificity of 100% (CI 86.7-100%), sensitivity of 19.4% (CI 10.7-30.8%), positive predictive value of 100% (CI 75.3-100%) and negative predictive value of 32,5% (CI 22,4-43,9%). Conclusions. A high frequency of immunoglobulin and Complement deficiency was observed in this JSLE series, suggesting that these defects may contribute to lupus development. Our findings indicate that these two groups of PID should be investigated in early-onset and severe lupus

Introdução: As infecções são importantes causas de morbidade e mortalidade em pacientes com lúpus eritematoso sistêmico juvenil (LESJ). No entanto, estudos avaliando somente infecções fúngicas invasivas (IFI) em pacientes com LESJ são restritos a relatos de casos ou série de casos, sem qualquer avaliação sistemática dos possíveis fatores de risco ou desfechos associados. A escassez de dados referentes às IFI em pacientes com LESJ e seu impacto sobre as características da doença em uma grande população levou ao desenvolvimento deste estudo multicêntrico. Objetivos: Estudar a prevalência, fatores de risco e mortalidade de IFI em pacientes com LESJ. Método: Um estudo de coorte multicêntrico retrospectivo foi realizado com 852 pacientes com LESJ de 10 Serviços de Reumatologia Pediátrica do Estado de São Paulo. Uma reunião foi realizada e todos os pesquisadores foram treinados para o preenchimento do banco de dados. As IFI foram diagnosticadas de acordo com as definições revisadas pelo grupo de consenso EORTC/MSG (comprovadas, prováveis ou possíveis). Foram coletados dados acerca de dados demográficos, características clínico-laboratoriais, atividade da doença (SLEDAI-2K), dano cumulativo (SLICC/ACR-DI) e tratamento, além de características e complicações das IFI. Resultados: IFI foram diagnosticadas em 33/852 (3,9%) pacientes com LESJ. IFI comprovadas foram diagnosticadas em 22 pacientes, IFI prováveis em 5 e IFI possíveis em 6. Os tipos de IFI encontradas foram: candidíase em 20 pacientes, aspergilose em 9, criptococose em 2, histoplasmose disseminada em um e paracoccidioidomicose em um. A mediana de duração da doença foi menor (1,0 vs. 4,7 anos, p < 0,0001), com maiores escores de SLEDAI-2K atual [19,5 (0-44) vs. 2 (0-45), p < 0,0001] e dose atual de prednisona [50 (10-60) vs. 10 (2-90) mg/dia, p < 0,0001] em pacientes com IFI em comparação com os pacientes sem IFI. A frequência de óbito foi maior no grupo com IFI (51% vs. 6%, p < 0,0001). A análise de regressão logística revelou que SLEDAI-2K atual (OR=1,108, IC 95%=1,057- 1,163, p < 0,0001), dose atual de prednisona (OR=1,046, IC 95%=1,021-1,071; p < 0,0001) e duração da doença (OR=0,984, IC 95%=0,969-0,998, p=0,030) foram fatores de risco independentes para IFI (R2 Nagelkerke 0,425). Conclusão: Este foi o primeiro estudo que caracterizou IFI em pacientes com LESJ. Identificou-se que a atividade da doença e uso de glicocorticoides foram os principais fatores de risco para estas infecções potencialmente graves, principalmente nos primeiros anos de curso da doença e com uma elevada taxa mortalidade / Introduction: Infections are an important cause of morbidity and mortality in childhoodonset systemic lupus erythematosus (cSLE) patients. However, studies evaluating solely invasive fungal infections (IFI) in cSLE patients are restricted to case reports or case series without any systematic evaluation of the possible associated risk factors and outcome in pediatric lupus population. The scarcity of data regarding IFI in cSLE patients and its impact on disease characteristics in a large population led to the development of this multicenter study. Objective: To study the prevalence, risk factors and mortality of IFI in cSLE patients. Methods: A retrospective multicenter cohort study was performed in 852 cSLE patients from 10 Pediatric Rheumatology services. An investigator meeting was held and all participants received database training. IFI were diagnosed according to EORTC/MSG Consensus Group criteria (proven, probable and possible). Demographic data, clinical, laboratorial, disease activity (SLEDAI-2K), cumulative damage (SLICC/ACR-DI) and treatment were collected. IFI were characterized and its outcome were also evaluated. Results: IFI were observed in 33/852 (3.9%) cSLE patients. Proven IFI was diagnosed in 22 cSLE patients, probable IFI in 5 and possible IFI in 6. Types of IFI were: 20 candidiasis, 9 aspergillosis, 2 cryptococcosis, one disseminated histoplasmosis and one paracoccidioidomycosis. The median of disease duration was lower (1.0 vs. 4.7 years, p < 0.0001), with a higher current SLEDAI-2K [19.5 (0-44) vs. 2 (0-45), p < 0.0001] and current prednisone dose [50 (10-60) vs. 10 (2-90) mg/day, p < 0.0001] in patients with IFI compared to those without IFI. The frequency of death was higher in the former group (51% vs. 6%, p < 0.0001). Logistic regression analysis revealed that current SLEDAI-2K (OR=1.108; 95%CI=1.057-1.163; p < 0.0001), prednisone current dose (OR=1.046; 95%CI=1.021-1.071; p < 0.0001) and disease duration (OR=0.984; 95%CI=0.969-0.998; p=0.03) were independent risk factors for IFI (R2 Nagelkerke 0.425). Conclusion: This was the first study that characterized IFI in cSLE patients. We identified that disease activity and glucocorticoid use were the main risk factors for these life-threatening infections, mainly in the first years of disease course and with a high rate of fatal outcome

Introdução: A suplementação de creatina tem surgido na literatura como uma potencial estratégia terapêutica não farmacológica em diversas condições caracterizadas por disfunções musculares e baixa massa muscular, incluindo as doenças reumatológicas pediátricas. O objetivo deste estudo foi avaliar a eficácia e a segurança da suplementação de creatina em pacientes com lúpus eritematoso sistêmico de início juvenil (LESJ). Métodos: Trata-se de um estudo duplo-cego, crossover, balanceado e controlado por placebo. Os voluntários (n = 15) foram randomizados em duas condições que receberam creatina ou dextrose por 12 semanas, interpassadas por um período de washout de 8 semanas. A função muscular foi avaliada por testes de uma repetição máxima (1 RM), Timed-Up-And-Go, Timed-Stands e de preensão manual. Ainda, foram avaliados a composição corporal, os marcadores bioquímicos do remodelamento ósseo, a aptidão aeróbia, os parâmetros de qualidade de vida e a capacidade funcional dos voluntários. As possíveis alterações no consumo alimentar foram avaliadas por três recordatórios alimentares de 24h, enquanto o conteúdo de fosforilcreatina muscular foi avaliado por meio de espectroscopia de fósforo por ressonância magnética (31P-ERM). A segurança da intervenção foi avaliada por parâmetros laboratoriais e por clearance de 51Cr-EDTA e, por fim, os eventos adversos foram registrados durante todo o estudo. Resultados: Não houve diferença significativa no conteúdo intramuscular de fosforilcreatina entre as condições, antes e após as intervenções (creatina - Pré: 20,5 ± 2,6/ Pós: 20,4 ± 4,1; placebo - Pré: 19,8 ± 2,0/ Pós: 20,2 ± 3,2 mmol/kg peso úmido; p = 0,70 para interação entre condições). Ainda, provavelmente, como consequência do conteúdo intramuscular ter se mantido inalterado, não houve diferença significativa entre as condições para todos os parâmetros analisados (p > 0,05). Além do clearance de 51Cr-EDTA não ter sido alterado com a suplementação de creatina, nenhum efeito adverso foi observado. Conclusão: O protocolo de suplementação de creatina (0,1 g/kg/d) por 12 semanas foi bem tolerado e livre de efeitos adversos. Entretanto, a suplementação de creatina não foi eficaz no aumento do conteúdo intramuscular de fosforilcreatina, na melhora da função muscular, aptidão aeróbia, composição corporal e parâmetros de qualidade de vida em pacientes com LESJ / Introduction: Creatine supplementation has emerged as a promising non-pharmacological therapeutic strategy to counteract muscle dysfunction and low lean mass in a variety of conditions, including in pediatric and rheumatic diseases. The objective of this study was to examine the efficacy and safety of creatine supplementation in childhood systemic lupus erythematosus (C-SLE). Methods: C-SLE patients with mild disease activity (n=15) received placebo or creatine supplementation in a randomized fashion using a crossover, double-blind, repeated-measures design. The subjects were assessed at baseline and after 12 weeks in each arm, interspersed by a 8-week washout period. The primary outcomes was muscle function, as assessed by a battery of tests including one-maximum repetition (1-RM) tests, the Timed-Up-And-Go test, the Timed-Stands test, and the handgrip test. Secondary outcomes included body composition, biochemical markers of bone remodeling, aerobic conditioning, quality of life, and physical capacity. Possible differences in dietary intake were assessed by three 24-h dietary recalls. Muscle phosphorylcreatine content was measured through phosphorus magnetic resonance spectroscopy (31P-MRS). The safety of the intervention was assessed by laboratory parameters and kidney function was measured by the 51Cr-EDTA clearance. Additionally, self-reported adverse events were recorded throughout the trial. Results: Intramuscular phosphorylcreatine content was not significantly different between creatine and placebo before or after the intervention (creatine - Pre: 20.5 ± 2.6, Post: 20.4 ± 4.1, placebo - Pre: 19.8 ± 2.0; Post: 20.2 ± 3.2 mmol/kg wet muscle; p = 0.70 for interaction between conditions). In addition, probably as a consequence of the lack of change in intramuscular phosphorylcreatine content, there were no significant changes between placebo and creatine for any muscle function and aerobic conditioning parameters, lean mass, fat mass, bone mass, and quality of life scores (p > 0.05). The 51Cr-EDTA clearance was not altered by creatine supplementation and no side effects were noticed. Conclusion: a 12-week creatine supplementation protocol at 0.1 g/kg/d is well tolerable and free of adverse effects but did not affect intramuscular phosphorylcreatine, muscle function, free-fat mass or quality of life in C-SLE patients with mild disease activity

Objetivo: Avaliar por HR-pQCT a densidade mineral óssea volumétrica (vDMO), a microarquitetura e as características biomecânicas do rádio distal e tíbia, assim como os marcadores laboratoriais do metabolismo ósseo em pacientes com lúpus eritematoso sistêmico de início juvenil (LESJ) comparados com controles saudáveis e determinar se este método permite identificar parâmetros que diferenciem pacientes com e sem fraturas vertebrais (FV). Métodos: Foram avaliadas 56 pacientes e comparadas a 56 controles saudáveis pareados por sexo, idade e estágio de Tanner. A HRpQCT foi realizada no rádio distal e na tíbia. Marcadores bioquímicos do metabolismo ósseo foram avaliados: pró-peptídeo amino-terminal do colágeno tipo I (P1NP), telo-peptídeo carboxi-terminal do colágeno tipo I (CTX), paratormônio intacto (iPTH), esclerostina (SOST) e 25hidroxivitamina D (25OHD). Fratura vertebral foi avaliada por VFA-DXA (método semiquantitativo de Genant). Resultados: Redução na densidade volumétrica e na resistência óssea, assim como comprometimento da microarquitetura óssea tanto cortical como trabecular foram encontrados em pacientes com LESJ comparados com controles saudáveis, principalmente no rádio distal (p < 0.05). Além disso, pacientes com FV apresentavam valores significantemente menores nos parâmetros trabeculares, somente no rádio distal, comparados com pacientes sem FV (Total.DMO: 229,45 ± 42,09 vs 275,93 ± 56,87 mg/cm3; p = 0,034; Trabecular.DMO [Tb.DMO]: 136,96 ± 30,84 vs 163,17 ± 30,45 mg/cm3; p = 0,034; BV/TV: 0,114 ± 0,026 vs 0,136 ± 0,029; p = 0,034) e também menores valores em relação a propriedades biomecânicas (Módulo Aparente: 1236 ± 334 vs 1523 ± 367 N/mm2; p = 0,039). Pacientes com fratura vertebral apresentaram maiores índices de SLICC/ACR-DI (0,67 ± 0,78 vs 0,11 ± 0,32; p = 0,002). Parâmetros laboratoriais do metabolismo ósseo foram semelhantes entre os grupos avaliados. Análise de regressão logística incluindo parâmetros que foram significativos na análise univariada revelaram que Tb.DMO (OR:0,98; 95%IC 0,95-0,99; p = 0,039) e SLICC/ACR-DI (OR:7,37; 95% IC 1,75-30,97; p = 0,006) foram fatores de risco independentes para fratura vertebral. Conclusões: Este é o primeiro estudo demonstrando que pacientes com lúpus de início juvenil apresentam alteração na microarquitetura e resistência óssea, particularmente no rádio distal. Além disso, nossos resultados demonstram que as fraturas vertebrais estão associadas a um comprometimento trabecular e também evidenciamos a associação do dano da doença nesta condição de fragilidade óssea / Objective: The aim of this study was to investigate using HR-pQCT the volumetric bone mineral density (vBMD), microarchitecture and biomechanical features at distal radius and tibia, and laboratory bone markers in JoSLE patients compared to controls and determine whether this method can discriminate JoSLE patients with or without VF. Methods: We compared 56 female JoSLE patients with age- and Tanner- matched healthy controls. HR-pQCT was performed at distal radius and at tibia. Serum levels of amino-terminal pro-peptide of type I collagen (P1NP), C-terminal telopeptide of type I collagen (CTX), intact parathormone (iPTH), sclerostin (SOST) and 25 hydroxivitamin D (25OHD) were evaluated. Vertebral fractures (VF) were analyzed by VFA-DXA (Genant\'s method). Results: Reduced parameters of density and strength as well as microarchitecture alteration of cortical and trabecular bone were observed in JoSLE patients compared to controls, mainly at distal radius (p < 0.05). In addition, patients with VF had a significant decrease in trabecular bone parameters solely at distal radius (Total.BMD: 229.45 ± 42.09 vs. 275.93 ± 56.87 mg/cm3; p = 0.034; Trabecular.BMD[Tb.BMD]: 136.96 ± 30.84 vs. 163.17 ± 30.45 mg/cm3; p = 0.034; BV/TV: 0.114 ± 0.026 vs. 0.136 ± 0.29; p=0.034; Apparent modulus: 1,236 ± 334 vs. 1,523 ± 367 N/mm2; p = 0.039) and higher score disease damage (SLICC/ACR-DI: 0.67 ± 0.78 vs. 0.11 ± 0.32; p = 0.002). Bone metabolism markers were alike in all groups evaluated. Logistic regression analysis including parameters that were significant at univariate analysis reveal that Tb.BMD (OR:0.98, 95%CI 0.95-0.99, p = 0.039) and SLICC/ACR-DI (OR:7.37, 95%CI 1.75-30.97, p=0.006) were independent risk factors for vertebral fractures. Conclusion: In conclusion, this is the first demonstration of bone microstructure and strength deficit in JoSLE patients, particularly at distal radius. Furthermore, our results show that VF are associated with trabecular radius compromise and emphasizes the potential detrimental effect of disease damage in this condition

<p>In sera remitted for anti-nuclear antibody (ANA) analysis, the supplement of a sensitive anti-SSA/Ro ELISA to the conventional ANA screening by immunofluorescence (IF) revealed that one fourth of the individuals with IF-ANA negative, but SSA/Ro ELISA positive sera, had systemic lupus erythematosus (SLE) or cutaneous LE. Consequently, adding a sensitive anti-SSA/Ro ELISA to the ANA screening is valuable for the serological detection of ANA negative SLE/LE patients.</p><p>SLE patients often have measurable interferon-alpha (IFN-α) levels in serum, and IFN-α treatment of patients with non-autoimmune diseases can induce SLE. Thus, the type I IFN system seems to be important in SLE and was therefore investigated. Initially, a decreased IFN-α producing capacity, due to a 70-fold reduction in the number of circulating natural IFN-α producing cells (NIPC), was noted in peripheral blood mononuclear cells (PBMC) from SLE patients. SLE-sera contained an endogenous IFN-α inducing factor (SLE-IIF), consisting of IgG and DNA in the form of small immune complexes (300-1000 kD). The SLE-IIF selectively activated NIPC and was more common in sera from patients with active disease compared to individuals with inactive disease. IFN-α producing cells could be detected by immunohistochemistry in both lesional and unaffected skin from SLE patients, and IFN-α gene transcription could be verified by in situ hybridisation in some of the skin biopsies. A reduced number of NIPC, detected by expression of the blood dendritic cell antigen (BDCA)-2, was noted among SLE-PBMC. The IFN-α production triggered by SLE-IIF in SLE-PBMC was inhibited by monoclonal antibodies (mAbs) to BDCA-2 and markedly decreased by anti-BDCA-4 mAbs. </p><p>The observations in the present thesis may explain the ongoing IFN-α production in SLE patients, indicate an important role for the activated type I IFN system in the pathogenesis, and suggest that direct targeting of SLE-NIPC may constitute a new therapeutic principle in SLE.</p>

<p>Patients with systemic lupus erythematosus (SLE) have an activated type I interferon (IFN) system with an ongoing IFN-α synthesis. This may be caused by circulating immune complexes, consisting of anti-DNA antibodies (Abs) and DNA, with IFN-α inducing capacity. Produced IFN-α may be crucial in the pathogenesis, because this cytokine can break tolerance and promote autoimmunity.</p><p>In the present thesis, possible mechanisms of the IFN-α production in SLE were studied. To investigate whether IFN-α inducing material could be derived from apoptotic cells, IgG from SLE patients (SLE-IgG) were combined with apoptotic cells. This combination induced high IFN-α production in normal peripheral blood mononuclear cells (PBMC). The IFN-α induction was associated to presence of anti-RNP Abs, but not to anti-dsDNA Abs, indicating that two inducers could be active in SLE, one containing DNA and the other RNA.</p><p>Apoptotic cells and SLE-IgG exclusively activated the natural interferon producing cells (NIPC) and the IFN-α response was enhanced by type I IFN and inhibited by IL-10 and TNF-α. The IFN-α induction was dependent on FcγRII, because blocking this receptor reduced IFN-α production and NIPC were found to express FcγRIIa.</p><p>To further elucidate the role of different autoantibodies in the IFN-α induction, sera from patients with Sjögren´s syndrome (SS), containing autoantibodies to RNA binding proteins (SSA, SSB, RNP and/or Sm) were investigated. The combination of SS or SLE sera and apoptotic or necrotic cell material induced high IFN-α production in PBMC. RNA, but not DNA, was required for IFN-α induction, indicating that RNA and Abs to RNA-binding proteins form potent IFN-α inducing complexes.</p><p>The findings in this thesis can explain central mechanisms for the activation of NIPC in SLE, and perhaps also other autoimmune diseases. This activation is mediated by interferogenic immune complexes, and modulating the NIPC activation may be a novel therapeutic approach in SLE.</p>

In sera remitted for anti-nuclear antibody (ANA) analysis, the supplement of a sensitive anti-SSA/Ro ELISA to the conventional ANA screening by immunofluorescence (IF) revealed that one fourth of the individuals with IF-ANA negative, but SSA/Ro ELISA positive sera, had systemic lupus erythematosus (SLE) or cutaneous LE. Consequently, adding a sensitive anti-SSA/Ro ELISA to the ANA screening is valuable for the serological detection of ANA negative SLE/LE patients. SLE patients often have measurable interferon-alpha (IFN-α) levels in serum, and IFN-α treatment of patients with non-autoimmune diseases can induce SLE. Thus, the type I IFN system seems to be important in SLE and was therefore investigated. Initially, a decreased IFN-α producing capacity, due to a 70-fold reduction in the number of circulating natural IFN-α producing cells (NIPC), was noted in peripheral blood mononuclear cells (PBMC) from SLE patients. SLE-sera contained an endogenous IFN-α inducing factor (SLE-IIF), consisting of IgG and DNA in the form of small immune complexes (300-1000 kD). The SLE-IIF selectively activated NIPC and was more common in sera from patients with active disease compared to individuals with inactive disease. IFN-α producing cells could be detected by immunohistochemistry in both lesional and unaffected skin from SLE patients, and IFN-α gene transcription could be verified by in situ hybridisation in some of the skin biopsies. A reduced number of NIPC, detected by expression of the blood dendritic cell antigen (BDCA)-2, was noted among SLE-PBMC. The IFN-α production triggered by SLE-IIF in SLE-PBMC was inhibited by monoclonal antibodies (mAbs) to BDCA-2 and markedly decreased by anti-BDCA-4 mAbs. The observations in the present thesis may explain the ongoing IFN-α production in SLE patients, indicate an important role for the activated type I IFN system in the pathogenesis, and suggest that direct targeting of SLE-NIPC may constitute a new therapeutic principle in SLE.

Patients with systemic lupus erythematosus (SLE) have an activated type I interferon (IFN) system with an ongoing IFN-α synthesis. This may be caused by circulating immune complexes, consisting of anti-DNA antibodies (Abs) and DNA, with IFN-α inducing capacity. Produced IFN-α may be crucial in the pathogenesis, because this cytokine can break tolerance and promote autoimmunity. In the present thesis, possible mechanisms of the IFN-α production in SLE were studied. To investigate whether IFN-α inducing material could be derived from apoptotic cells, IgG from SLE patients (SLE-IgG) were combined with apoptotic cells. This combination induced high IFN-α production in normal peripheral blood mononuclear cells (PBMC). The IFN-α induction was associated to presence of anti-RNP Abs, but not to anti-dsDNA Abs, indicating that two inducers could be active in SLE, one containing DNA and the other RNA. Apoptotic cells and SLE-IgG exclusively activated the natural interferon producing cells (NIPC) and the IFN-α response was enhanced by type I IFN and inhibited by IL-10 and TNF-α. The IFN-α induction was dependent on FcγRII, because blocking this receptor reduced IFN-α production and NIPC were found to express FcγRIIa. To further elucidate the role of different autoantibodies in the IFN-α induction, sera from patients with Sjögren´s syndrome (SS), containing autoantibodies to RNA binding proteins (SSA, SSB, RNP and/or Sm) were investigated. The combination of SS or SLE sera and apoptotic or necrotic cell material induced high IFN-α production in PBMC. RNA, but not DNA, was required for IFN-α induction, indicating that RNA and Abs to RNA-binding proteins form potent IFN-α inducing complexes. The findings in this thesis can explain central mechanisms for the activation of NIPC in SLE, and perhaps also other autoimmune diseases. This activation is mediated by interferogenic immune complexes, and modulating the NIPC activation may be a novel therapeutic approach in SLE.

Systemic lupus erythematosus (SLE) is the prototypic systemic autoimmune disease, whereas autoimmune polyendocrine syndrome type 1 (APS1) is a rare autosomal disorder characterized by combinations of organ-specific autoimmune manifestations including hypoparathyroidism and intestinal dysfunction, and may serve as a model for organ-specific autoimmunity. Autoantibodies directed against proteins expressed in the affected tissues are found in both diseases. From a chondrocyte cDNA expression library, we identified the protein AHNAK as an autoantigen in SLE. Anti-AHNAK antibodies were found in 29.5% (18/61) of patients with SLE, 4.6% (5/109) of patients with rheumatoid arthritis, and 1.2% (2/172) of blood donors. Using a candidate approach, we analyzed the prevalence in APS1 and other organ-specific autoimmune diseases, of autoantibodies against the pyridoxal phosphate-dependent enzymes histidine decarboxylase (HDC) and cysteine sulfinic acid decarboxylase (CSAD), which are structurally closely related to known autoantigens. Anti-HDC and anti-CSAD reactivity was detected exclusively in APS1 patient sera. Anti-HDC antibodies were detected in 37.1% (36/97) of the APS1 sera, did not cross-react with aromatic L-amino acid decarboxylase, and were associated with intestinal dysfunction and loss of histamine-producing gastric enterochromaffin-like cells. In contrast, anti-CSAD reactivity was detected in 3.6% (3/83) of APS1 sera and cross-reacted with recombinant glutamic acid decarboxylase. From a parathyroid cDNA expression library, novel spliced transcripts of the CLLD4 gene on human chromosome 13q14, encoding 26 and 31 kDa isoforms recognized by autoantibodies in 3.4% (3/87) of APS1 patients, were identified and found to be preferentially expressed in lung and ovary. Both isoforms contain an N-terminal BTB/POZ domain, similarly to the TNF-alpha-regulated protein B12, localize both to the cytoplasm and nucleus in transfected COS cells, and form oligomers in vitro. The CLLD4 gene is located in a region frequently deleted in several forms of cancer, including lung and ovarian tumors. In conclusion, we have identified and partially characterized AHNAK and HDC as two common targets of autoantibodies in SLE and APS1, respectively. We have also identified CSAD and CLLD4 as two minor autoantigens in APS1, one of which is a novel protein with unknown function.