Introdução: O infliximabe é um anticorpo monoclonal quimérico que inibe o fator de necrose tumoral, sendo usado em doenças autoimunes e/ou inflamatórias, tais como a artrite reumatóide (AR), a espondilite anquilosante (EA), a psoríase e a artrite psoriásica (AP) e as doenças inflamatórias intestinais (DII). Objetivos: Avaliar se o infliximabe induz à formação de autoanticorpos e verificar a ocorrência de eventos adversos, sobretudo o lúpus induzido por este medicamento. Metodologia: Trata-se de um estudo aberto, prospectivo, de fase IV, onde dosamos os autoanticorpos antes e depois do tratamento (das doenças citadas anteriormente), o qual teve duração mínima de 6 meses (5 infusões). Resultados: No total, 286 pacientes foram avaliados para o fator anti-nuclear (FAN) por imunofluorescência indireta em células Hep2, sendo significativo o aumento de número de indivíduos (p = 0,0001), antes e depois da medicação. Além do FAN, foram dosados, em 146 pacientes, 17 outros autoanticorpos pelo método multiplex, sendo que o anti-DNA de dupla hélice (anti-dsDNA) e o anticardiolipina IgM (aCL IgM) tiveram um aumento significativo (p = 0,003 e 0,0024, respectivamente). Pacientes com AR tiveram uma variação significativa nos títulos do anticorpo anti-proteína citrulinada (ACPA) (antes e depois do tratamento) (p = 0,012). De todos os pacientes avaliados (n = 286), somente 1 (0,35%) apresentou sinais clínicos e laboratoriais de lúpus induzido pelo infliximabe. Conclusão: O estudo demonstrou que o infliximabe interferiu na formação de autoanticorpos (FAN, anti-dsDNA, aCL IgM e ACPA), sendo rara a indução de lúpus pelo medicamento. / Background: Infliximab is a chimeric monoclonal antibody that inhibits tumor necrosis factor, and is thus used in the treatment of autoimmune and/or inflammatory diseases, such as rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriasis and psoriatic arthritis (PA), and inflammatory bowel diseases (IBD). Objective: To determine whether infliximab induces the formation of autoantibodies and assess the occurrence of adverse effects, mainly drug-induced lupus. Method: The study consisted of a phase IV, prospective, open-label trial, in which autoantibody levels were determined before and after treatment (of the above mentioned diseases) with a minimum duration of 6 months (5 infusions). Results: A total of 286 patients were assessed for the presence of antinuclear antibodies (ANA) by means of indirect immunofluorescence on human epithelial (HEp-2) cells, with a significant increase in the number of individuals observed after treatment (p = 0.0001). In addition to ANA, 17 other autoantibodies were assessed in 146 patients using multiplex technology, and a significant increase was observed in anti-double stranded DNA (anti-dsDNA) and anticardiolipin IgM (aCL IgM) antibody titers (p = 0.003 and 0.0024, respectively). Patients with RA showed significant variations in anti-citrullinated protein antibody (ACPA) titers (before and after treatment) (p = 0.012). Among the 286 patients assessed, only 1 (0.35%) presented clinical and laboratory signs of infliximab-induced lupus. Conclusion: The present study showed that infliximab did affect the formation of autoantibodies (ANA, anti-dsDNA, aCL IgM and ACPA), with a rare occurrence of drug-induced lupus.

Introdução: O infliximabe é um anticorpo monoclonal quimérico que inibe o fator de necrose tumoral, sendo usado em doenças autoimunes e/ou inflamatórias, tais como a artrite reumatóide (AR), a espondilite anquilosante (EA), a psoríase e a artrite psoriásica (AP) e as doenças inflamatórias intestinais (DII). Objetivos: Avaliar se o infliximabe induz à formação de autoanticorpos e verificar a ocorrência de eventos adversos, sobretudo o lúpus induzido por este medicamento. Metodologia: Trata-se de um estudo aberto, prospectivo, de fase IV, onde dosamos os autoanticorpos antes e depois do tratamento (das doenças citadas anteriormente), o qual teve duração mínima de 6 meses (5 infusões). Resultados: No total, 286 pacientes foram avaliados para o fator anti-nuclear (FAN) por imunofluorescência indireta em células Hep2, sendo significativo o aumento de número de indivíduos (p = 0,0001), antes e depois da medicação. Além do FAN, foram dosados, em 146 pacientes, 17 outros autoanticorpos pelo método multiplex, sendo que o anti-DNA de dupla hélice (anti-dsDNA) e o anticardiolipina IgM (aCL IgM) tiveram um aumento significativo (p = 0,003 e 0,0024, respectivamente). Pacientes com AR tiveram uma variação significativa nos títulos do anticorpo anti-proteína citrulinada (ACPA) (antes e depois do tratamento) (p = 0,012). De todos os pacientes avaliados (n = 286), somente 1 (0,35%) apresentou sinais clínicos e laboratoriais de lúpus induzido pelo infliximabe. Conclusão: O estudo demonstrou que o infliximabe interferiu na formação de autoanticorpos (FAN, anti-dsDNA, aCL IgM e ACPA), sendo rara a indução de lúpus pelo medicamento. / Background: Infliximab is a chimeric monoclonal antibody that inhibits tumor necrosis factor, and is thus used in the treatment of autoimmune and/or inflammatory diseases, such as rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriasis and psoriatic arthritis (PA), and inflammatory bowel diseases (IBD). Objective: To determine whether infliximab induces the formation of autoantibodies and assess the occurrence of adverse effects, mainly drug-induced lupus. Method: The study consisted of a phase IV, prospective, open-label trial, in which autoantibody levels were determined before and after treatment (of the above mentioned diseases) with a minimum duration of 6 months (5 infusions). Results: A total of 286 patients were assessed for the presence of antinuclear antibodies (ANA) by means of indirect immunofluorescence on human epithelial (HEp-2) cells, with a significant increase in the number of individuals observed after treatment (p = 0.0001). In addition to ANA, 17 other autoantibodies were assessed in 146 patients using multiplex technology, and a significant increase was observed in anti-double stranded DNA (anti-dsDNA) and anticardiolipin IgM (aCL IgM) antibody titers (p = 0.003 and 0.0024, respectively). Patients with RA showed significant variations in anti-citrullinated protein antibody (ACPA) titers (before and after treatment) (p = 0.012). Among the 286 patients assessed, only 1 (0.35%) presented clinical and laboratory signs of infliximab-induced lupus. Conclusion: The present study showed that infliximab did affect the formation of autoantibodies (ANA, anti-dsDNA, aCL IgM and ACPA), with a rare occurrence of drug-induced lupus.

Background: Rheumatoid arthritis (RA) is a common complex autoimmune disorder which is influenced by both genetic and environmental factors. While multiple factors that influence susceptibility to and outcome of disease have been identified there is still a large proportion of missing heritability and limited understanding of disease pathogenesis. In recent years, biologic drug therapies have advanced treatment of RA; however good disease control is achieved in just 30% of patients, making identification of predictors of treatment response important. One area of research which is yet to be explored in relation to treatment response, and requires further evaluation in RA susceptibility, is epigenetics. Epigenetics is the study of modifications of the DNA which can influence gene expression but do not alter genetic sequence, and the most commonly studied epigenetic phenomenon, to date, is DNA methylation. Objectives: To identify DNA methylation signatures predictive of treatment response to anti-TNF biologics, to explore the role of DNA methylation in RA susceptibility using disease discordant monozygotic (MZ) twins, and to assess the effect of cryopreservation of cells on DNA methylation. Methods: Genome-wide DNA methylation levels were measured using the HumanMethylation450 BeadChip in pre-treatment whole blood DNA samples from individuals who had extremely good or extremely poor response to the anti-TNF therapies, etanercept and adalimumab, and in MZ twins discordant for RA (n=79 pairs). I also compared genome-wide methylation in cells which had been cryopreserved with fresh cells, to investigate if this technique is suitable for epigenetic investigations. Results: I identified four methylation sites which were significantly related to response to etanercept at a false discovery rate of 5%, the most significantly differentially methylated of which maps to the LRPAP1 gene (p=1.46E-8). Indeed, four other sites at the same locus also showed evidence for differential methylation indicating that this represents a differentially methylated region. No sites were significantly associated with response to adalimumab after correction for multiple testing. I identified subtle differences in DNA methylation between RA discordant twins. Although these were not statistically significant following adjustment for cell composition, one of the most differentially methylated positions mapped to the ZNF74 gene (p=4.97E-6), and replicated a methylation difference identified in the largest previous epigenome-wide association study of RA cases and unrelated healthy controls. I found that cryopreservation of cells does not significantly alter the methylome, an important observation that will impact upon design of future studies. Conclusions: In the largest studies of DNA methylation in RA treatment response and RA discordant MZ twins to date, I identified significant differential methylation in etanercept response, but not adalimumab response, and found small differences in methylation in RA discordant MZ twins. I also concluded that cryopreservation does not significantly alter the methylome.