Title Participants Abstract "Longterm Followup of Rituximab Therapy in Patients with Rheumatoid Arthritis: Results from the Belgian MabThera in Rheumatoid Arthritis Registry" "Ilse Hoffman, Rene Westhovens" "Our study reports the results of the MIRA (MabThera In Rheumatoid Arthritis) registry, set up to collect data about clinical usage, patient profile, and retention of rituximab (RTX) treatment in daily clinical practice in Belgium." "Collagen-induced arthritis as an animal model for rheumatoid arthritis: role of IFN-gamma in immunomodulation by mesenchymal stem cells and in extra-articular manifestations." "Evelien Schurgers" "Over an extended period of time, work in our laboratory focused on unravelling the role of interferon-γ (IFN-γ) in collagen-induced arthritis (CIA), a well characterised animal model for human rheumatoid arthritis (RA). IFN-γ was found to display anti-inflammatory properties in CIA since IFN-γ receptor knock-out (IFN-γR KO) mice developed CIA more rapidly and with a higher severity as compared to their wild-type counterparts. The protective effect of IFN-γ could be explained by its suppressive effects on neutrophil mobilisation, activation of macrophages/osteoclasts and its role in the activation of regulatory T cells. The dogma that IFN-γ acts as a proinflammatory cytokine was questioned by these findings. Moreover, IFN-γ could be considered a novel therapy for RA, a perception confirmed by numerous clinical trials concerning IFN-γ in RA. In the quest for novel therapies for RA, mesenchymal stem cells (MSCs) have recently been proposed. They are multipotent cells that combine interesting characteristics such as tissue regeneration and immunosuppression and might therefore prove to be ideal therapeutics for RA. Since IFN-γ has been identified as an activator of the immuosuppressive capacities of MSCs, in this thesis we investigated the potential of MSCs to suppress the joint pathology in CIA and the effect of IFN-γ on this suppression. Although the joint pathology in CIA resembles that of RA remarkably well, RA is associated with extra-articular manifestations in for instance lung tissue. In CIA no reports of pulmonary involvement were reported. In this thesis we therefore investigated whether mice with CIA would develop pulmonary manifestations and analysed the role of IFN-γ on this systemic pathology.MSCs were isolated from the bone marrow of wild-type and IFN-γR KO mice and after several passages homogenous populations of MSCs were obtained. By culturing anti-CD3-stimulated T cells in vitro in the presence of MSCs we could demonstrate that T cell responses were suppressed by MSCs in a dose-dependent manner. IFN-γR KO MSCs were less suppressive than wild-type MSCs, indicating an IFN-γ-dependent mechanism was involved in the T cell suppression. By stimulating MSCs with IFN-γ we could demonstrate that the production of programmed death ligand-1, inducible nitric oxide synthase and cyclo-oxygenase-2, but not indoleamine 2,3-dioxygenase was involved in the immunosuppression mediated by MSCs. Despite their potent in vitro suppressive effects, MSCs were unable to counteract in vivo anti-CD3-induced T cell proliferation in mice. MSCs also failed to suppress CIA, even when they were administered at multiple time points or via different routes. This was reflected in unchanged humoral and cellular responses towards collagen type II. Together these data demonstrate that the immunosuppressive potential of MSCs in vitro can not be extrapolated to an in vivo situation.When MSCs are considered as a therapeutic in RA, thorough investigation of the effect of MSCs on all cell types involved in the pathogenesis of RA is necessary. Therefore, we investigated the effect of MSCs on osteoclasts, the cell type responsible for bone degradation in the joints of RA patients. Using mouse embryo fibroblasts (MEFs) as a source of fibroblasts, we developed an in vitro co-culture system between MEFs and splenocytes from mice with CIA. We could demonstrate that MEFs could stimulate the development of osteoclasts from splenocytes even without addition of osteoclast growth factors. When MEFs were substituted by MSCs, no osteoclasts could be detected. Only when receptor activator of nuclear factor-kB ligand (RANKL), a potent osteoclast inducer, was added osteoclasts developed. In the presence of tumor necrosis factor-α (TNF-α), osteoclasts were also not formed. Thus, MSCs can only support osteoclast differentiation when RANKL is present. As a consequence, whether MSCs will induce osteoclast differentiation in the joint of RA patients will probably depend on the cytokine balance present in the joint and administration of these cels in inflammatory conditions (containing RANKL and TNF-α) possibly has detrimental effects.As a second main goal in this thesis, we investigated whether pulmonary manifestations, which regularly complicate RA, were also present in CIA in mice. On macroscopic examination of the lungs 21 days after the induction of CIA, lesions could be detected on the surface of the lungs in IFN-γR KO mice but not in wild-type mice. Elevated numbers of macrophages and neutrophils were detected in bronchoalveolar lavage fluid of IFN-γR KO mice. Upon histological examination of the lungs, perivascular and peribronchial lymphocytic infiltrates as well as subpleural nodular accumulations of neutrophils and histiocytes could be visualised in lungs of arthritic IFN-γR KO mice but not wild-type mice. In IFN-γR KO mice, this pulmonary infiltration was accompanied by elevated mRNA levels of proinflammatory cytokines and chemokines. Upon functional assessment of the lungs, impaired lung function was ascertained which presented as a stiffening of the lungs. Treating the mice with anti-TNF-α therapy resulted in a complete prevention of joint pathology and a partial but significant reduction of the pulmonary complications. These data indicate that extra-articular manifestations in CIA can be provoked in CIA by interfering with one cytokine signaling pathway i.e. IFN-γ.Previous doctoral research in our laboratory demonstrated that upon immunisation with complete Freunds adjuvant (CFA) without the cartilage antigen collagen type II, IFN-γR KO mice develop arthritic symptoms which are identical to the joint pathology observed in CIA. Upon examination of the lungs, we could demonstrate that IFN-γR KO mice with CFA-induced arthritis displayed similar pulmonary pathology as IFN-γR KO mice with CIA. An important component of CFA is heat-killed Mycobacterium butyricum. Since this M. butyricum is the common factor in both arthritis models, we focused our attention to the M. butyricum to find a possible cause of the lung involvement. After fluorescent labelling of the M. butyricum, we could determine that the M. butyricum was present in the lungs of immunised animals. Thus, from these data we can conclude that M. butyricum used for the induction of CIA and CFA-induced arthritis translocates to the lungs after immunisation of IFN-γR KO mice and might locally cause production of proinflammatory cytokines and chemokines, followed by pulmonary inflammation.Summarising our investigations, we can state that although MSCs display potent immunosuppressive potential in vitro, they were unable to counteract in vivo T cell proliferation or CIA. Furthermore, MSCs could, depending on the local cytokine balance, possibly stimulate the development of osteoclasts. These findings are important to keep in mind when considering MSCs as potential therapy for RA. Although CIA is generally considered not to be associated with extra-articular manifestations, we could demonstrate that IFN-γR KO mice with CIA did present with pulmonary pathology. This finding adds relevance to the animal model and offers clear future perspectives both on fundamental and clinical level. We feel that on fundamental level, the model is suited to investigate the association between environmental factors, such as smoking, citrullination in the lungs and the development of arthritis. The fact that these extra-articular manifestations mainly occur in mice that have a mutation in the IFN-γ receptor, might offer new perspectives to the clinic such as treatment of RA patients with IFN-γ, possibly combined with current therapies." "Collagen-induced arthritis as an animal model for rheumatoid arthritis: focus on interferon-γ" "Alfons Billiau, Patrick Matthys" "Rheumatoid arthritis (RA), an autoimmune disease causing inflammation, destruction, and deformity of the joints, affects around 1% of the world population. It is a systemic disease as patients exhibit extra-articular manifestations as well. Collagen-induced arthritis (CIA) in DBA/1 mice is one of the many animal models used to study possible pathogenic mechanisms of RA. It involves immunizing mice with collagen type II in complete Freund's adjuvant. Here we briefly review the general characteristics of RA and CIA and present an overview of data obtained by studying CIA in several gene knockout mice. In particular, detailed analysis of CIA in interferon-gamma (IFN-γ) receptor-deficient mice has pin-pointed IFN-γ as an important cytokine in the pathogenesis and has exposed new functions of IFN-γ in immunological processes. Pilot trials with exogenous IFN-γ in RA have been indicative of a beneficial effect. That improvement of the disease symptoms by IFN-γ treatment was not spectacular may be explained by the fact that RA is a heterogeneous disease in which the severity of the autoimmune disease is strongly determined by environmental factors." "HIGHER COMORBIDITY BURDEN IN EARLY PSORIATIC ARTHRITIS AS COMPARED TO EARLY RHEUMATOID ARTHRITIS: CLUES FOR PATHOGENESIS OF PSORIATIC DISEASE" "Rik Lories" "The impact of T-cell co-stimulation modulation in patients with undifferentiated inflammatory arthritis or very early rheumatoid arthritis: a clinical and imaging study of abatacept" "Rene Westhovens" "BACKGROUND: Several agents provide treatment for established RA, but a crucial therapeutic goal is to delay/prevent progression of undifferentiated arthritis (UA) or very early RA. METHODS: In this double-blind, Phase II, placebo-controlled 2-year study, anti-CCP2-positive patients with UA (not fulfilling the ACR criteria for RA) and clinical synovitis of >/=2 joints were randomized to abatacept (~10 mg/kg) or placebo for 6 months, then study drug was terminated. The primary endpoint was development of RA (by ACR criteria) at Year 1. Patients were monitored by radiography, MRI, CCP2, RF, DAS28 and 28-joint count over 2 years. RESULTS: At Year 1, 12/26 (46%) abatacept-treated versus 16/24 (67%) placebo-treated patients developed RA (difference [95% CI] -20.5% [-47.4, 7.8]). Adjusted mean changes from baseline to Year 1 in Genant-modified Sharp radiographic scores for abatacept- versus placebo-treated patients, respectively, were: 0 versus 1.1 for TS, and 0 versus 0.9 for ES. Mean changes from baseline to Year 1 in MRI erosion, osteitis and synovitis scores were 0, 0.2 and 0.2, respectively, versus 5.0, 6.7 and 2.3 in the abatacept versus placebo groups. Safety was comparable between groups; serious AEs occurred in one patient (3.6%) in each group. CONCLUSION: Abatacept delayed progression of UA/very early RA in some patients. An impact on radiographic and MRI inhibition was observed, which was maintained for 6 months after therapy cessation. This suggests that it is possible to alter the progression of RA by modulating T-cell responses at a very early stage of disease." "Construction and psychometric properties of the Belgian Rheumatoid Arthritis Disability Assessment (BRADA) questionnaire : a new tool for the evaluation of activity limitations in patients with rheumatoid arthritis" "Xavier Janssens, Saskia Decuman, Filip De Keyser" "Objectives: To describe the construction and psychometric properties of the Belgian Rheumatoid Arthritis Disability Assessment (BRADA) questionnaire, a self-report tool to evaluate chronic activity limitations in patients with rheumatoid arthritis (RA). The BRADA was developed to assess the eligibility of patients with RA for financial and social support measures. Methods: The BRADA questionnaire evaluates functioning in 6 functional domains (mobility, nutrition, self care, household tasks, awareness of danger and communication) over the past week and the past 3 months. To assess the psychometric properties of the BRADA, patients with moderate to severe RA filled out the BRADA, HAQ-DI and SF-36 questionnaires twice, with a four-week interval. At each visit, the total number of swollen and tender joints, and global disease activity were recorded. DAS 28 was measured at the first visit. Internal consistency of items per domain was evaluated with Cronbach's alpha method. Intraclass correlation coefficient (ICC) analysis was used to assess test-retest reliability. BRADA scores were compared to HAQ, SF-36 scores and disease activity parameters with Spearman's Rho correlation coefficients to assess construct validity. Results: Experts considered the content and face validity of BRADA to be adequate. Internal consistency was satisfactory for all functional domains (alpha >0.75), as was the test-retest reliability (ICC 0.78). BRADA scores showed excellent correlation with other validated questionnaires in RA (HAQ-DI, SF-36) and with measures of disease activity (VAS, DAS28) (p" "Rate of Anti-Cyclic Citrullinated Peptide Antibody and Rheumatoid Factor Seroconversion in Patients with Undifferentiated Arthritis or Early Rheumatoid Arthritis Treated with Abatacept." "Tom WJ Huizinga, Paul Emery, Rene Westhovens, Manuela Le Bars, Corine Gaillez, Coralie Poncet, Ayanbola Elegbe, Josef S Smolen" "Comparison of the Belgian Rheumatoid Arthritis Disability Assessment and Health Assessment questionnaires as tools to predict the need for support measures in patients with rheumatoid arthritis" "Xavier Janssens, Saskia Decuman, Filip De Keyser" "Proposal for Levels of Evidence Schema for Validation of a Soluble Biomarker Reflecting Damage Endpoints in Rheumatoid Arthritis, Psoriatic Arthritis, and Ankylosing Spondylitis, and Recommendations for Study Design" "Walter P. Maksymowych, Oliver Fitzgerald, George A. Wells, Dafna D. Gladman, Robert Landewe, Mikkel Ostergaard, William J. Taylor, Robin Christensen, Paul-Peter Tak, Maarten Boers, Silje W. Syversen, Joan M. Bathon, Christopher J. Ritchlin, Philip J. Mease, Vivien P. Bykerk, Patrick Garnero, Piet GEUSENS, Hani El-Gabalawy, Daniel Aletaha, Robert D. Inman, Virginia Byers Kraus, Tore K. Kvien, Desiree VAN DER HEIJDE" "Objective. At OMERACT 8 a framework for levels of evidence was proposed for the validation of biomarkers as surrogate outcome measures. We aimed to adapt this scheme in order to apply it in the setting Of Soluble biomarkers proposed to replace the measurement of damage endpoints in rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS). We also aimed to generate consensus on minimum standards for the design of longitudinal Studies aimed at validating biomarkers. Methods. Before the meeting, the Soluble Biomarker Working Group prepared a preliminary framework and discussed various models for association and prediction related to the statistical strength domain. In addition, 3 Delphi exercises addressing longitudinal study design for RA, PsA. and AS were conducted within the working group and members of the Assessments in SpondyloArthritis International Society (ASAS) and the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA). This formed the basis for discussions among OMERACT 9 participants. Results. The proposed framework was accepted by consensus. In the study design domain a requirement for both prospective observational Studies and randomized controlled trials (RCT) in different drug classes was noted. A template for determining the level of statistical strength was proposed. The addition of a new domain on biomarker assay performance was considered essential, and participants suggested that for any biomarker this domain should be addressed first, i.e., before starting clinical validation studies. Participants agreed on most elements of a longitudinal study design template. Where consensus was lacking the working group has drafted solutions that constitute a basis for prospective validation studies. Conclusion. The OMERACT 9 Soluble Biomarker Group has successfully formulated a levels of evidence scheme and a study design template that will provide guidance to conduct validation studies in the setting of soluble biomarkers proposed to replace the measurement of damage endpoints in RA, PsA, and AS. (J Rheumatol 2009:36:1792-9;, doi. 10.3899/jrheum.090347)" "Reappraisal of OMERACT 8 Draft Validation Criteria for a Soluble Biomarker Reflecting Structural Damage Endpoints in Rheumatoid Arthritis, Psoriatic Arthritis, and Spondyloarthritis: The OMERACT 9 v2 Criteria" "Walter P. Maksymowych, Robert Landewe, Paul-Peter Tak, Christopher J. Ritchlin, Mikkel Ostergaard, Philip J. Mease, Hani El-Gabalawy, Patrick Garnero, Dafna D. Gladman, Oliver Fitzgerald, Daniel Aletaha, Vivien P. Bykerk, Joan M. Bathon, Silje W. Syversen, Maarten Boers, Piet GEUSENS, Robert D. Inman, Virginia B. Kraus, Tore K. Kvien, William J. Taylor, George A. Wells, Desiree VAN DER HEIJDE" "Objectives. A draft set of criteria for the validation of soluble biomarkers reflecting damage endpoints was proposed at OMERACT 8. At OMERACT 9 we aimed to scrutinize the necessity for each of these criteria according to the objectives of the working group. Methods. The OMERACT 8 draft criteria and the principle objectives of the validation process were clarified at a meeting of the working group in London, December 2007. A new framework was proposed after the following steps were conducted: (A) A systematic review of the literature focusing on the draft criteria and a preselected group of biomarkers (MMP3, CTX-II, RANKL, OPG, CTX-I) followed by a Delphi consensus exercise addressing the importance of individual criteria and identification of omissions in the draft set. (13) Formal debate its well as group discussion centered oil the key arguments for inclusion/exclusion of specific criteria. (C) Onsite interactive electronic voting on the importance of specific criteria. The framework was presented and discussed at OMERACT 9 in both breakout and plenary sessions followed by a vote on its acceptance. Results. The objectives of rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis biomarkers in relation to their predictive validity for damage endpoints was clarified and supported by OMERACT 9 participants. The OMERACT 8 draft validation criteria were reformulated into an essential category focused on criteria addressin the OMERACT Filter elements of discrimination 9 (incorporating truth) and feasibility, and a desirable but nonessential category of other criteria addressing, truth. This revised draft set was endorsed by participants at OMERACT 9. Conclusion. A revised set of validation criteria has been drafted by consensus at OMERACT 9 that focuses on the performance characteristics of biomarker assays, the importance of addressing potential confounders, and the essential requirement for clinical validation studies. (J Rheumatol 2009; 36:1785-91. doi: 10.3899/jrheum.090346)"