Therapy targeting antigen-specific T cells by a peptide-based tolerizing vaccine against autoimmune arthritis.

A longstanding goal has been to find an antigen-specific preventive therapy, i.e., a vaccine, for autoimmune diseases. It has been difficult to find safe ways to steer the targeting of natural regulatory antigen. Here, we show that the administration of exogenous mouse major histocompatibility complex class II protein bounding a unique galactosylated collagen type II (COL2) peptide (Aq-galCOL2) directly interacts with the antigen-specific TCR through a positively charged tag. This leads to expanding a VISTA-positive nonconventional regulatory T cells, resulting in a potent dominant suppressive effect and protection against arthritis in mice. The therapeutic effect is dominant and tissue specific as the suppression can be transferred with regulatory T cells, which downregulate various autoimmune arthritis models including antibody-induced arthritis. Thus, the tolerogenic approach described here may be a promising dominant antigen-specific therapy for rheumatoid arthritis, and in principle, for autoimmune diseases in general.

The role of YAP1 target gene CTGF in the anoikis resistance of rheumatoid arthritis synovial fibroblasts.

OBJECTIVE: To analyse pro-survival mechanisms elicited in RA synovial fibroblasts (RASFs) upon detachment from their extracellular matrix dependent on the disintegrin metalloproteinase ADAM15 and Yes-associated protein kinase 1 (YAP1). METHODS: Detachment-induced apoptosis was determined by caspase 3/7 assays. Immunofluorescent stainings, cell surface biotinylation and immunoblotting were applied to analyse phosphorylated kinases and subcellular localization of YAP1 and connective tissue growth factor (CTGF). Caspase and transwell transmigration assays served to study CTGF function. RESULTS: Silencing of ADAM15 or YAP1 in RASFs leads to significantly increased levels of detachment-induced caspase activity. In non-silenced RASFs detachment causes simultaneous ADAM15-enhanced phosphorylation of YAP1 at S127, known for promoting its cytoplasmic localization, and Src-dependent phosphorylation at tyrosine Y357. The majority of nuclear YAP1 leaves the nucleus shortly after cell detachment, but prolonged detachment causes a marked nuclear re-entry of YAP1, resulting in significantly increased synthesis of CTGF. The newly synthesized CTGF, however, is not detectable in the supernatant, but is bound to the outside of the plasma membrane. In vitro studies demonstrated autocrine binding of CTGF to the EGF receptor and ß1 integrin, with concomitant triggering of survival kinases, AKT1, ERK1/2, Src and focal adhesion kinase. Functional studies revealed anti-apoptotic effects of CTGF on detached RASFs and an enhancement of their potential for endothelial transmigration using HUVEC-coated transwells. CONCLUSION: The elucidation of a new molecular mechanism that protects RASFs in the highly pro-apoptotic environment of inflamed RA joints by promoting anoikis-resistance and transendothelial migration via ADAM15/YAP1-mediated CTGF upregulation uncovers potentially new targets for future therapeutic intervention.

The role of antidrug antibodies in ustekinumab therapy and the impact of methotrexate.

OBJECTIVE: We investigated the impact of concomitant MTX on ustekinumab (UST) levels and antidrug antibody (ADA) formation in PsA and evaluated consequences in pharmacodynamics and pharmacokinetics. METHODS: We conducted a post-hoc analysis on 112 PsA serum samples of subjects treated with open-label UST and either concomitant MTX (UST/MTX, n = 58) or placebo (UST/pbo, n = 54) obtained in a randomized (1:1), double-blind, multicentre trial. A validated antibody-binding-based multitiered testing was used to detect ADA and ADA with neutralizing capacity (nADA). The impact of MTX on UST immunogenicity was analysed by comparison of UST/pbo with UST/MTX cohorts at different time points. Patient- and disease-related predispositions for ADA formation were investigated with multiple linear regression analysis. Immunogenicity impact on pharmacokinetics, safety and efficacy was determined by cohort comparison between patients with and without ADA formation. RESULTS: Over 52 weeks, 11 UST/pbo- and 19 UST/MTX-treated patients developed ADA (P > 0.05). In the UST/pbo cohort, the visit-dependent UST levels were in the range of 0.047 (0.05) -0.110 (0.07) µg/ml overall, and 0.037 (0.04)-0.091 (0.08) µg/ml in ADA-confirmed subjects. In UST/MTX-treated patients, the UST levels exhibited an intervisit variation in the range of 0.0502 (0.04)-0.106 (0.07) µg/ml overall and 0.029 (0.03)-0.097 (0.07) µg/ml in ADA positive subjects (P > 0.05). At week 52, ADA-confirmed patients did not differ significantly (P > 0.05) in safety or clinical outcomes from ADA-negative patients. CONCLUSION: Concomitant MTX had no significant impact on UST immunogenicity. Furthermore, ADA formation was not associated with impairments in UST safety, efficacy or trough levels. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT03148860.

[Mechanisms of immunological tolerance and their dysregulation in rheumatic diseases]. / Mechanismen immunologischer Toleranz und ihrer Dysregulation bei rheumatischen Erkrankungen.

The major tasks of the immune system are protection against infectious agents, maintaining homeostasis by recognizing and neutralizing noxious substances from the environment, and monitoring pathological, e.g. neoplastic tissue changes. It accomplishes these tasks through complex interactions of cellular and humoral components of the innate and adaptive immune system. This review article focuses on a central problem of self versus non-self discrimination in the development of B and T lymphocytes as carriers of adaptive immunity. During maturation of the lymphocytes in the bone marrow, large repertoires of lymphocyte receptors are randomly generated by somatic recombination, which as a whole have the capability of recognizing any foreign antigen. In order to reduce the implicit risk of autoaggressive immunity that might arise from evolutionary conserved structural motifs in self and foreign antigens, the adaptive immune system must provide redundant mechanisms (clonal deletion, anergy, quiescence and suppression) to eliminate or inactivate lymphocytes expressing highly avid receptors for autoantigens. Thus, the provision of costimulatory signals resulting in a reduced activation threshold of potentially autoreactive anergic T cells through infection, molecular mimicry, disrupted apoptosis regulation, altered "self" by post-translational modification, genetic changes in transcription factors with critical importance for thymic tolerance induction or signaling components of apoptosis can lead to a disruption of self-tolerance and the induction of pathogenic autoimmunity.

[Epidemiological data and medical care situation of patients with chronic inflammatory diseases in Germany : Real-world evidence on prevalence, disease combinations, care]. / Epidemiologische Daten und medizinische Versorgungssituation von Patienten mit chronischen Entzündungserkrankungen in Deutschland : Real-World-Evidenz zu Prävalenz, Erkrankungskombinationen, Versorgung.

BACKGROUND: Chronic inflammatory diseases (immune-mediated inflammatory diseases, IMID) can overlap or occur simultaneously due to clinical similarities. The resulting utilization of heathcare structures has not yet been investigated across disciplines but is of potential importance for optimizing the treatment of patients with IMID. AIM OF THE WORK: Analysis of epidemiological data including utilization of care services in patients with selected IMIDs: psoriasis, psoriatic arthritis (PsA), rheumatoid arthritis (RA), ankylosing spondylitis, ulcerative colitis, Crohn's disease and connective tissue disease. MATERIAL AND METHODS: In a retrospective cross-sectional analysis based on health insurances accounting data with a sample of approximately 4 million insured persons, the prevalence of the abovementioned IMID and the frequency of IMID combinations were analyzed based on documented diagnoses (ICD-10 GM). The frequency of hospitalizations and utilization of outpatient physician contacts was recorded in predefined specialist disciplines (general medicine, dermatology, gastroenterology, rheumatology) and compared with an age-adjusted and gender-adjusted reference population. RESULTS: A total of 188,440 patients had at least 1 of the IMID diagnoses analyzed (4.7%), with an age peak of 61-70 years. The highest prevalence was observed for psoriasis (1.85%), followed by rheumatoid arthritis (1.38%). Combinations with at least one other IMID were relatively common (29%), with this being most common in patients with psoriatic arthritis (82.9%, of which 68.2% had psoriasis), followed by ankylosing spondylitis (27.5%) and Crohn's disease (21.6%). Compared to the reference population, patients with IMID were hospitalized more often and more frequently utilized the outpatient disciplines. DISCUSSION: The study results describe that IMIDs occur in combination and that the patients make comparatively more use of care structures of different disciplines. A multidisciplinary approach could increase the efficiency of care; an evaluation is still pending.

Key interactions in the trimolecular complex consisting of the rheumatoid arthritis-associated DRB1*04:01 molecule, the major glycosylated collagen II peptide and the T-cell receptor.

OBJECTIVES: Rheumatoid arthritis (RA) is an autoimmune disease strongly associated with the major histocompatibility complex (MHC) class II allele DRB1*04:01, which encodes a protein that binds self-peptides for presentation to T cells. This study characterises the autoantigen-presenting function of DRB1*04:01 (HLA-DRA*01:01/HLA-DRB1*04:01) at a molecular level for prototypic T-cell determinants, focusing on a post-translationally modified collagen type II (Col2)-derived peptide. METHODS: The crystal structures of DRB1*04:01 molecules in complex with the peptides HSP70289-306, citrullinated CILP982-996 and galactosylated Col2259-273 were determined on cocrystallisation. T cells specific for Col2259-273 were investigated in peripheral blood mononuclear cells from patients with DRB1*04:01-positive RA by cytofluorometric detection of the activation marker CD154 on peptide stimulation and binding of fluorescent DRB1*0401/Col2259-273 tetramer complexes. The cDNAs encoding the T-cell receptor (TCR) α-chains and ß-chains were cloned from single-cell sorted tetramer-positive T cells and transferred via a lentiviral vector into TCR-deficient Jurkat 76 cells. RESULTS: The crystal structures identified peptide binding to DRB1*04:01 and potential side chain exposure to T cells. The main TCR recognition sites in Col2259-273 were lysine residues that can be galactosylated. RA T-cell responses to DRB1*04:01-presented Col2259-273 were dependent on peptide galactosylation at lysine 264. Dynamic molecular modelling of a functionally characterised Col2259-273-specific TCR complexed with DRB1*04:01/Col2259-273 provided evidence for differential allosteric T-cell recognition of glycosylated lysine 264. CONCLUSIONS: The MHC-peptide-TCR interactions elucidated in our study provide new molecular insights into recognition of a post-translationally modified RA T-cell determinant with a known dominant role in arthritogenic and tolerogenic responses in murine Col2-induced arthritis.

Rituximab plus leflunomide in rheumatoid arthritis: a randomized, placebo-controlled, investigator-initiated clinical trial (AMARA study).

OBJECTIVE: To investigate the efficacy and safety of rituximab + LEF in patients with RA. METHODS: In this investigator-initiated, randomized, double-blind, placebo-controlled phase 3 trial, patients with an inadequate response to LEF who had failed one or more DMARD were randomly assigned 2:1 to i.v. rituximab 1000 mg or placebo on day 1 and 15 plus ongoing oral LEF. The primary efficacy outcome was the difference between ≥50% improvement in ACR criteria (ACR50 response) rates at week 24 (P ≤ 0.025). Secondary endpoints included ACR20/70 responses, ACR50 responses at earlier timepoints and adverse event (AE) rates. The planned sample size was not achieved due to events beyond the investigators' control. RESULTS: Between 13 August 2010 and 28 January 2015, 140 patients received rituximab (n = 93) or placebo (n = 47) plus ongoing LEF. Rituximab + LEF resulted in an increase in the ACR50 response rate that was significant at week 16 (32 vs 15%; P = 0.020), but not week 24 (27 vs 15%; P = 0.081), the primary endpoint. Significant differences favouring the rituximab + LEF arm were observed in some secondary endpoints, including ACR20 rates from weeks 12 to 24. The rituximab and placebo arms had similar AE rates (71 vs 70%), but the rituximab arm had a higher rate of serious AEs (SAEs 20 vs 2%), primarily infections and musculoskeletal disorders. CONCLUSION: The primary endpoint was not reached, but rituximab + LEF demonstrated clinical benefits vs LEF in secondary endpoints. Although generally well tolerated, the combination was associated with additional SAEs and requires monitoring. TRIAL REGISTRATION: EudraCT: 2009-015950-39; ClinicalTrials.gov: NCT01244958.

Genetic variants in FBLIM1 gene do not contribute to SAPHO syndrome and chronic recurrent multifocal osteomyelitis in typical patient groups.

BACKGROUND: Syndrome of synovitis acne pustulosis hyperostosis osteitis (SAPHO) and chronic recurrent multifocal osteomyelitis (CRMO) present two diseases of a dermatologic and rheumatologic spectrum that are variable in manifestation und therapeutic response. Genetic risk factors have long been assumed in both diseases, but no single reliable factor has been identified yet. Therefore, we aimed to clinically characterize a patient group with syndrome of synovitis acne pustulosis hyperostosis osteitis (SAPHO) (n = 47) and chronic recurrent multifocal osteomyelitis (CRMO)/ chronic non-bacterial osteomyelitis (CNO) (n = 9) and analyze a CRMO candidate gene. METHODS: Clinical data of all patients were collected and assessed for different combinations of clinical symptoms. SAPHO patients were grouped into categories according to the acronym; disease-contribution by pathogens was evaluated. We sequenced coding exons of FBLIM1. RESULTS: Palmoplantar pustular psoriasis (PPP) was the most common skin manifestation in CRMO/CNO and SAPHO patients; most SAPHO patients had sterno-costo-clavicular hyperostosis. The most common clinical category of the acronym was S_PHO (n = 26). Lack of pathogen detection from bone biopsies was more common than microbial isolation. We did not identify autosomal-recessive FBLIM1 variants. CONCLUSIONS: S_PHO is the most common combination of symptoms of its acronym. Genetic analyses of FBLIM1 did not provide evidence that this gene is relevant in our patient group. Our study indicates the need to elucidate SAPHO's and CRMO/CNO's pathogenesis.

Individual therapeutic DAS28-dcrit responses differentiate between effectiveness of rheumatoid arthritis therapies and reflect patient-reported outcomes: retrospective analysis of DAS28 responses in comparative tocilizumab studies.

Assessment of individual therapeutic responses provides valuable information concerning treatment benefits in individual patients. We evaluated individual therapeutic responses as determined by the Disease Activity Score-28 joints critical difference for improvement (DAS28-dcrit) in rheumatoid arthritis (RA) patients treated with intravenous tocilizumab or comparator anti-tumor necrosis factor (TNF) agents. The previously published DAS28-dcrit value [DAS28 decrease (improvement) ≥ 1.8] was retrospectively applied to data from two studies of tocilizumab in RA, the 52-week ACT-iON observational study and the 24-week ADACTA randomized study. Data were compared within (not between) studies. DAS28 was calculated with erythrocyte sedimentation rate as the inflammatory marker. Stability of DAS28-dcrit responses and European League Against Rheumatism (EULAR) good responses was determined by evaluating repeated responses at subsequent timepoints. A logistic regression model was used to calculate p values for differences in response rates between active agents. Patient-reported outcomes (PROs; pain, global health, function, and fatigue) in DAS28-dcrit responder versus non-responder groups were compared with an ANCOVA model. DAS28-dcrit individual response rates were 78.2% in tocilizumab-treated patients and 58.2% in anti-TNF-treated patients at week 52 in the ACT-ion study (p = 0.0001) and 90.1% versus 59.1% at week 24 in the ADACTA study (p < 0.0001). DAS28-dcrit responses showed greater stability over time (up to 52 weeks) than EULAR good responses. For both active treatments, DAS28-dcrit responses were associated with statistically significant improvements in mean PRO values compared with non-responders. The DAS28-dcrit response criterion provides robust assessments of individual responses to RA therapy and may be useful for discriminating between active agents in clinical studies and guiding treat-to-target decisions in daily practice.

The sneaking ligand approach for cell type-specific modulation of intracellular signalling pathways.

Small molecules interfering with intracellular signalling pathways are used in the treatment of multiple diseases including RA. However, small molecules usually affect signalling in most cell types, not only in those which need to be targeted. This general inhibition of signalling pathways causes often adverse effects, which could be avoided by cell type-specific inhibitors. For cell-type specific modulation of signal transduction, we developed the sneaking ligand fusion proteins (SLFPs). SLFPs contain three domains: (1) the binding domain mediating cell type-specific targeting and endocytosis; (2) the endosomal release sequence releasing the effector domain into the cytoplasm; (3) the effector domain modulating signalling. Using our SLFP NF-kappaB inhibitor termed SLC1 we demonstrated that cell-type-specific modulation of intracellular signalling pathways is feasible, that endothelial NF-kappaB activation is critical for arthritis and peritonitis and that SLFPs help to identify disease-relevant pathways in defined cell types. Hence, SLFPs may improve risk-benefit ratios of therapeutic interventions.

High-sensitive troponin is associated with subclinical imaging biosignature of inflammatory cardiovascular involvement in systemic lupus erythematosus.

BACKGROUND: Cardiovascular (CV) involvement in patients with systemic lupus erythematosus (SLE) is presumably subclinical for the major part of its evolution. We evaluated the associations between high-sensitive troponin T (hs-TropT), a sensitive marker of myocardial injury, and CV involvement using cardiac magnetic resonance (CMR). METHODS AND RESULTS: This is a two-centre (London and Frankfurt) CMR imaging study at 3.0 Tesla of consecutive 92 patients with SLE free of cardiac symptoms, undergoing screening for cardiac involvement. Venous samples were drawn and analysed post-hoc for cardiac biomarkers, including hs-TropT, high-sensitive C reactive protein and N-terminal pro brain natriuretic peptide. Compared with age-matched/gender-matched non-SLE controls (n=78), patients had significantly raised cardiac biomarker levels, native T1 and T2, aortic and ventricular stiffness, and reduced global longitudinal strain (p<0.01). In SLE, hs-TropT was significantly and independently associated with native T2, followed by the models including native T1 and aortic stiffness (Χ2 0.462, p<0.01). There were no relationships between hs-TropT and age, gender, CV risk factors, duration of systemic disease, cardiac structure or function, or late gadolinium enhancement. CONCLUSIONS: Patients with SLE have a high prevalence of subclinical myocardial injury as demonstrated by raised high-sensitive troponin levels. CMR with T2 mapping reveals myocardial oedema as the strongest predictor of hs-TropT release, underscoring the inflammatory interstitial remodelling as the main mechanism of injury. Patients without active myocardial inflammation demonstrate diffuse interstitial remodelling and increased vascular stiffness. These findings substantiate the role of CMR in screening of subclinical cardiac involvement. TRIAL REGISTRATION NUMER: NCT02407197; Results.

Minimal disease activity is a stable measure of therapeutic response in psoriatic arthritis patients receiving treatment with adalimumab.

Objective: The aim of this study was to evaluate minimal disease activity (MDA) assessments in patients with PsA during routine clinical care. Methods: We used data from a multicentre observational study of patients with active PsA who initiated treatment with adalimumab during routine clinical practice and continued treatment for at least 6 months to evaluate achievement of MDA, individual MDA criteria (modified to conform to study assessments) and ACR responses during 24 months of therapy. Pearson correlation coefficients were used to evaluate the association between MDA and individual criteria at month 6; regression models were used to determine the influence of baseline MDA criteria on achievement of MDA at month 6. Results: A total of 1684 patients were included in these analyses; most had long-standing disease. MDA was achieved by 597 patients (35.5%) at month 6. This proportion increased to 45.5% at month 24 in patients remaining on therapy. MDA status was stable over time; >75% of patients with MDA at month 6 recorded MDA at subsequent visits. Pain was the most difficult individual criterion to achieve, and enthesitis was the least difficult. Higher functional status and fewer tender joints at baseline predicted achievement of MDA at month 6. About half of patients (51.5%) with an ACR20 response at month 6 achieved MDA. Conclusion: In this observational cohort of patients with long-standing disease, MDA provided a stable and valid assessment of clinical status over 24 months. Trial registration: Clinicaltrials.gov, https://clinicaltrials.gov, NCT01111240.

Genome-wide association and targeted analysis of copy number variants with psoriatic arthritis in German patients.

BACKGROUND: Psoriatic Arthritis (PsA) is a chronic inflammatory disease of the joints. PsA is etiologically complex, and 11 susceptibility loci have been identified so far. Most of these overlap with loci associated with psoriasis vulgaris (PsV), the most common psoriatic skin manifestation which is also frequently seen in PsA patients. In addition, two copy number variants (CNVs) are associated with PsV, one of which, located within the LCE3 gene cluster, is also associated with PsA. Finally, an intergenic deletion has been reported as a PsA-specific CNV. METHODS: We performed a genome-wide association study (GWAS) of CNVs in PsA and assessed the contribution to disease risk by CNVs at known psoriasis susceptibility loci. RESULTS: After stringent quality assessment and validation of CNVs of the GWAS with an alternative quantitative method, two significantly associated CNVs remained, one near UXS1, the other one at the TRB locus. However, MLPA analysis did not confirm the CN state in ~1/3 of individuals, and an analysis of an independent case-control-study failed to confirm the initial associations. Furthermore, detailed PCR-based analysis of the sequence at TRB revealed the existence of a more complex genomic sequence most accurately represented by freeze hg18 which accordingly failed to confirm the hg19 sequence. Only rare CNVs were detected at psoriasis susceptibility loci. At three of 12 susceptibility loci with CNVs (CSMD1, IL12B, RYR2), CN variability was confirmed independently by MLPA. Overall, the rate of CNV confirmation by MLPA was strongly dependent upon CNV type, CNV size and the number of array markers involved in a CNV. CONCLUSION: Although we identified PsA associations at several loci and confirmed that the common CNVs at these sites were real, ~1/3 of the common CNV states could not be reproduced. Furthermore, replication analysis failed to confirm the original association. Furthermore, SNP array-based analyses of CNVs were found to be more reliable for deletions than duplications, independent of the respective CNV allele frequency. CNVs are thus good candidate disease variants, while the methods to detect them should be applied cautiously and reproduced by an independent method.

Treating rheumatoid arthritis to target: 2014 update of the recommendations of an international task force.

BACKGROUND: Reaching the therapeutic target of remission or low-disease activity has improved outcomes in patients with rheumatoid arthritis (RA) significantly. The treat-to-target recommendations, formulated in 2010, have provided a basis for implementation of a strategic approach towards this therapeutic goal in routine clinical practice, but these recommendations need to be re-evaluated for appropriateness and practicability in the light of new insights. OBJECTIVE: To update the 2010 treat-to-target recommendations based on systematic literature reviews (SLR) and expert opinion. METHODS: A task force of rheumatologists, patients and a nurse specialist assessed the SLR results and evaluated the individual items of the 2010 recommendations accordingly, reformulating many of the items. These were subsequently discussed, amended and voted upon by >40 experts, including 5 patients, from various regions of the world. Levels of evidence, strengths of recommendations and levels of agreement were derived. RESULTS: The update resulted in 4 overarching principles and 10 recommendations. The previous recommendations were partly adapted and their order changed as deemed appropriate in terms of importance in the view of the experts. The SLR had now provided also data for the effectiveness of targeting low-disease activity or remission in established rather than only early disease. The role of comorbidities, including their potential to preclude treatment intensification, was highlighted more strongly than before. The treatment aim was again defined as remission with low-disease activity being an alternative goal especially in patients with long-standing disease. Regular follow-up (every 1-3 months during active disease) with according therapeutic adaptations to reach the desired state was recommended. Follow-up examinations ought to employ composite measures of disease activity that include joint counts. Additional items provide further details for particular aspects of the disease, especially comorbidity and shared decision-making with the patient. Levels of evidence had increased for many items compared with the 2010 recommendations, and levels of agreement were very high for most of the individual recommendations (≥9/10). CONCLUSIONS: The 4 overarching principles and 10 recommendations are based on stronger evidence than before and are supposed to inform patients, rheumatologists and other stakeholders about strategies to reach optimal outcomes of RA.

Anti-citrullinated protein antibodies are linked to erosive disease in an observational study of patients with psoriatic arthritis.

OBJECTIVE: ACPAs are associated with bone destruction in RA. The aim of this study was to evaluate the association between ACPA and bone destruction in patients with a distinct inflammatory disorder, PsA. METHODS: We used baseline data from a large observational study of PsA patients preparing to initiate treatment with adalimumab to analyse demographic and disease characteristics by ACPA status. To ensure a homogeneous PsA study population, only patients with active psoriatic skin manifestations who met Classification of Psoriatic Arthritis criteria for PsA were included in the analyses, thereby minimizing the risk of including misdiagnosed RA patients. Multiple logistic regression analyses were used to explore potential associations between ACPA seropositivity and bone destruction. RESULTS: Of 1996 PsA patients who met the strict inclusion criteria, 105 (5.3%) were positive for ACPA. ACPA-positive patients had significantly higher swollen joint counts and 28-joint DAS values than ACPA-negative patients and significantly higher rates of erosive changes and dactylitis. Multiple logistic regression analysis confirmed the association of ACPA seropositivity with a 2.8-fold increase in the risk of erosive disease. CONCLUSION: As has been previously shown for RA, ACPA is associated with bone destruction in PsA, suggesting that the osteocatabolic effect of ACPA is not confined to RA but is also detectable in the different pathogenetic context of a distinct disease entity. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01111240.

NF-κB inhibitor targeted to activated endothelium demonstrates a critical role of endothelial NF-κB in immune-mediated diseases.

Activation of the nuclear transcription factor κB (NF-κB) regulates the expression of inflammatory genes crucially involved in the pathogenesis of inflammatory diseases. NF-κB governs the expression of adhesion molecules that play a pivotal role in leukocyte-endothelium interactions. We uncovered the crucial role of NF-κB activation within endothelial cells in models of immune-mediated diseases using a "sneaking ligand construct" (SLC) selectively inhibiting NF-κB in the activated endothelium. The recombinant SLC1 consists of three modules: (i) an E-selectin targeting domain, (ii) a Pseudomonas exotoxin A translocation domain, and (iii) a NF-κB Essential Modifier-binding effector domain interfering with NF-κB activation. The E-selectin-specific SLC1 inhibited NF-κB by interfering with endothelial IκB kinase 2 activity in vitro and in vivo. In murine experimental peritonitis, the application of SLC1 drastically reduced the extravasation of inflammatory cells. Furthermore, SLC1 treatment significantly ameliorated the disease course in murine models of rheumatoid arthritis. Our data establish that endothelial NF-κB activation is critically involved in the pathogenesis of arthritis and can be selectively inhibited in a cell type- and activation stage-dependent manner by the SLC approach. Moreover, our strategy is applicable to delineating other pathogenic signaling pathways in a cell type-specific manner and enables selective targeting of distinct cell populations to improve effectiveness and risk-benefit ratios of therapeutic interventions.

Autoimmune priming, tissue attack and chronic inflammation - the three stages of rheumatoid arthritis.

Extensive genome-wide association studies have recently shed some light on the causes of chronic autoimmune diseases and have confirmed a central role of the adaptive immune system. Moreover, better diagnostics using disease-associated autoantibodies have been developed, and treatment has improved through the development of biologicals with precise molecular targets. Here, we use rheumatoid arthritis (RA) as a prototype for chronic autoimmune disease to propose that the pathogenesis of autoimmune diseases could be divided into three discrete stages. First, yet unknown environmental challenges seem to activate innate immunity thereby providing an adjuvant signal for the induction of adaptive immune responses that lead to the production of autoantibodies and determine the subsequent disease development. Second, a joint-specific inflammatory reaction occurs. This inflammatory reaction might be clinically diagnosed as the earliest signs of the disease. Third, inflammation is converted to a chronic process leading to tissue destruction and remodeling. In this review, we discuss the stages involved in RA pathogenesis and the experimental approaches, mainly involving animal models that can be used to investigate each disease stage. Although we focus on RA, it is possible that a similar stepwise development of disease also occurs in other chronic autoimmune settings such as multiple sclerosis (MS), type 1 diabetes, and systemic lupus erythematosus.

MOR103, a human monoclonal antibody to granulocyte-macrophage colony-stimulating factor, in the treatment of patients with moderate rheumatoid arthritis: results of a phase Ib/IIa randomised, double-blind, placebo-controlled, dose-escalation trial.

OBJECTIVES: To determine the safety, tolerability and signs of efficacy of MOR103, a human monoclonal antibody to granulocyte-macrophage colony-stimulating factor (GM-CSF), in patients with rheumatoid arthritis (RA). METHODS: Patients with active, moderate RA were enrolled in a randomised, multicentre, double-blind, placebo-controlled, dose-escalation trial of intravenous MOR103 (0.3, 1.0 or 1.5 mg/kg) once a week for 4 weeks, with follow-up to 16 weeks. The primary outcome was safety. RESULTS: Of the 96 randomised and treated subjects, 85 completed the trial (n=27, 24, 22 and 23 for pooled placebo and MOR103 0.3, 1.0 and 1.5 mg/kg, respectively). Treatment emergent adverse events (AEs) in the MOR103 groups were mild or moderate in intensity and generally reported at frequencies similar to those in the placebo group. The most common AE was nasopharyngitis. In two cases, AEs were classified as serious because of hospitalisation: paronychia in a placebo subject and pleurisy in a MOR103 0.3 mg/kg subject. Both patients recovered fully. In exploratory efficacy analyses, subjects in the MOR103 1.0 and 1.5 mg/kg groups showed significant improvements in Disease Activity Score-28 scores and joint counts and significantly higher European League Against Rheumatism response rates than subjects receiving placebo. MOR103 1.0 mg/kg was associated with the largest reductions in disease activity parameters. CONCLUSIONS: MOR103 was well tolerated and showed preliminary evidence of efficacy in patients with active RA. The data support further investigation of this monoclonal antibody to GM-CSF in RA patients and potentially in those with other immune-mediated inflammatory diseases. TRIAL REGISTRATION NUMBER: NCT01023256.

PTPN22 is associated with susceptibility to psoriatic arthritis but not psoriasis: evidence for a further PsA-specific risk locus.

OBJECTIVES: Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis; it has a higher estimated genetic component than psoriasis alone, however most genetic susceptibility loci identified for PsA to date are also shared with psoriasis. Here we attempt to validate novel single nucleotide polymorphisms selected from our recent PsA Immunochip study and determine specificity to PsA. METHODS: A total of 15 single nucleotide polymorphisms were selected (PImmunochip <1×10(-4)) for validation genotyping in 1177 cases and 2155 controls using TaqMan. Meta-analysis of Immunochip and validation data sets consisted of 3139 PsA cases and 11 078 controls. Novel PsA susceptibility loci were compared with data from two large psoriasis studies (WTCCC2 and Immunochip) to determine PsA specificity. RESULTS: We found genome-wide significant association to rs2476601, mapping to PTPN22 (p=1.49×10(-9), OR=1.32), but no evidence for association in the psoriasis cohort (p=0.34) and the effect estimates were significantly different between PsA and psoriasis (p=3.2×10(-4)). Additionally, we found genome-wide significant association to the previously reported psoriasis risk loci; NOS2 (rs4795067, p=5.27×10(-9)). CONCLUSIONS: For the first time, we report genome-wide significant association of PTPN22 (rs2476601) to PsA susceptibility, but no evidence for association to psoriasis.

Anti-TNFα-therapy as an evidence-based treatment option for different clinical manifestations of psoriatic arthritis.

The development programmes of different TNF-blocking agents in psoriatic arthritis (PsA) not only provided substantial evidence for the therapeutic benefits of the specific treatment options, but also enabled new insights into the differential treatment effects on distinct disease manifestations. For the first time, specific robust evidence for distinctive effects on different manifestations of PsA, as a distinct entity separate from rheumatoid arthritis (RA), has been generated in a standardized way. The clearest evidence was shown for an effect on peripheral arthritis (polyarticular) with ACR20 response rates from 45 up to 58% (vs. 9-24% for placebo), and an inhibition of radiographic progression demonstrated for the first time for a treatment principle in PsA. However, as PsA does not remain confined to the peripheral joints, it was necessary to address diverse patterns of PsA-subtypes in the outcome measurements of the anti-TNF trials. Accordingly, the results of the clinical studies on anti-TNF treatment also have demonstrated efficacy on enthesitis, dactylitis and skin psoriasis, either in sub analysis of results from phase III RCTs, or in additional prospective studies.