Anti-TNF therapy reduces serum levels of chemerin in rheumatoid arthritis: a new mechanism by which anti-TNF might reduce inflammation

BACKGROUND

Chemerin is a specific chemoattractant for macrophages and dendritic cells (DC). In addition, it can rapidly stimulate macrophage adhesion to extracellular matrix proteins and adhesion molecules and is able to activate fibroblast-like synoviocytes (FLS), suggesting a role in the pathogenesis of rheumatoid arthritis (RA). Chemerin is also an adipocytokine that has been related to the inflammatory state of endothelial cells and as such could be involved in the changes in endothelial cells in RA and perhaps increased cardiovascular morbidity. We investigated whether anti-Tumor Necrosis Factor (TNF) treatment affects chemerin levels.

MATERIALS AND METHODS

49 patients with active RA (disease activity score evaluated in 28 joints (DAS28) ≥3.2) were started on adalimumab therapy. Blood was drawn from patients while fasting at baseline and 16 weeks after initiation of treatment. Chemerin serum levels were measured by ELISA and related to disease activity, mediators of inflammation and known risk factors for cardiovascular disease.

RESULTS

Adalimumab therapy reduced chemerin serum levels, which was correlated with the reduction in DAS28 (r = 0.37, p = 0.009). In addition, the decrease in chemerin serum levels after anti-TNF treatment was associated with the decrease in serum levels of IL-6 (r = 0.39, p = 0.033) and macrophage migration inhibitory factor (MIF) (r = 0.31, p = 0.049). Baseline chemerin serum levels were not related to traditional risk factors for atherosclerosis, except perhaps for smoking (p = 0.07).

CONCLUSIONS

This exploratory study shows that adalimumab therapy lowers chemerin levels, which is associated with the reduction in disease activity parameters, and inflammatory mediators IL-6 and MIF. This suggests a possible involvement of chemerin in the migration/retention of macrophages in the synovium. TRIAL REGISTRATION NEDERLANDS TRIAL REGISTER: NTR 857.

Efficacy and safety of secukinumab, a fully human anti-interleukin-17A monoclonal antibody, in patients with moderate-to-severe psoriatic arthritis: a 24-week, randomised, double-blind, placebo-controlled, phase II proof-of-concept trial

OBJECTIVE

To evaluate the efficacy and safety of secukinumab, a fully human, anti-interleukin (IL)-17A monoclonal antibody, in patients with psoriatic arthritis (PsA).

METHODS

42 patients with active PsA fulfilling ClASsification for Psoriatic ARthritis (CASPAR) criteria were randomly assigned (2:1) to receive two intravenous secukinumab doses (10 mg/kg; n=28) or placebo (n=14) 3 weeks apart. The primary endpoint was the proportion of American College of Rheumatology (ACR) 20 responses at week 6 for secukinumab versus placebo (one-sided p<0.1).

RESULTS

Primary endpoint: ACR20 responses at week 6 were 39% (9/23) for secukinumab versus 23% (3/13) for placebo (p=0.27). ACR20 responses were greater with secukinumab versus placebo at week 12 (39% (9/23) vs 15% (2/13), p=0.13) and week 24 (43% (10/23) vs 18% (2/11), p= 0.14). At week 6, 'good' European League Against Rheumatism response was seen in 21.7% (5/23) secukinumab versus 9.1% (1/11) placebo patients. Compared with placebo at week 6, significant reductions were observed among secukinumab recipients for C reactive protein (p=0.039), erythrocyte sedimentation rate (p=0.038), Health Assessment Questionnaire Disability Index (p=0.002) and Short Form Health Survey (SF-36; p=0.030) scores. The overall adverse event (AE) frequency was comparable between secukinumab (26 (93%)) and placebo (11 (79%)) recipients. Six serious AEs (SAEs) were reported in four secukinumab patients and one SAE in one placebo patient.

CONCLUSIONS

Although the primary endpoint was not met, clinical responses, acute-phase reactant and quality of life improvements were greater with secukinumab versus placebo, suggesting some clinical benefit. Secukinumab exhibited satisfactory safety. Larger clinical trials of secukinumab in PsA are warranted.

Relationship between inflammation, bone destruction, and osteoproliferation in the HLA-B27/human β2 -microglobulin-transgenic rat model of spondylarthritis

OBJECTIVE

Inhibition of inflammation and destruction, but not of osteoproliferation, in patients with spondylarthritis (SpA) treated with anti-tumor necrosis factor raises the question of how these three processes are interrelated. This study was undertaken to analyze this relationship in a rat model of SpA.

METHODS

Histologic spine and joint samples from HLA-B27/human β(2) -microglobulin (hβ(2) m)-transgenic rats were analyzed for signs of spondylitis and destructive arthritis and semiquantitatively scored as showing mild, moderate, or severe inflammation.

RESULTS

In rats exhibiting spondylitis, mildly inflamed sections displayed lymphocyte infiltration in connective tissue adjacent to the junction of the anulus fibrosus and vertebral bone but not at the enthesis. Moderately inflamed tissue samples contained osteoclasts eroding bone outside the cartilage end plate. In sections from rats with severe inflammation, the cartilage end plate and underlying bone marrow were also affected. End-stage disease was characterized by complete destruction of the intervertebral disc and vertebrae, with ongoing infiltration. Osteoproliferation was not observed in samples from rats with no or mild inflammation, but was present at the edge of the vertebrae in sections with moderate inflammation and persisted during severe inflammation and end-stage destruction. Osteoproliferation occurred at the border of inflammation, at a distance from bone destruction. A strong correlation between the extent of inflammation, destruction, and osteoproliferation was observed. Sections from rats with arthritis displayed a similar pattern of synovial inflammation associated with bone destruction, and simultaneous but topographically distinct osteoproliferation starting from the periosteum.

CONCLUSION

SpA in B27/hβ(2) m-transgenic rats is characterized by destructive inflammatory pannus tissue rather than by enthesitis or osteitis. Destruction and osteoproliferation occur simultaneously but at distinct sites in joints with moderate to severe inflammation.

Local administration of soluble CD40:Fc to the salivary glands of non-obese diabetic mice does not ameliorate autoimmune inflammation

Objective

CD40–CD154 (CD40 ligand) interaction in the co-stimulatory pathway is involved in many (auto)immune processes and both molecules are upregulated in salivary glands of Sjögren’s syndrome (SS) patients. Interference within the CD40 pathway has ameliorated (auto)inflammation in a number of disease models. To test the potential role of the CD40 pathway in loss of gland function and inflammation in SS, an inhibitor of CD40-CD154 interaction was overexpressed in the salivary glands (SGs) of a spontaneous murine model of SS; the Non-Obese Diabetic (NOD) mouse.

Materials and Methods

At different disease stages an adeno associated viral vector encoding CD40 coupled to a human Fc domain (CD40:Fc) was injected locally into the SGs of NOD mice. Delivery was confirmed by PCR. The overall effect on local inflammation was determined by assessment of the focus score (FS), quantification of infiltrating cell types, immunoglobulin levels, and microarray analysis. The effect on SG function was determined by measuring stimulated salivary flow.

Results

CD40:Fc was stably expressed in the SG of NOD mice, and the protein was secreted into the blood stream. Microarray analysis revealed that expression of CD40:Fc affected the expression of many genes involved in regulation of the immune response. However, FS, infiltrating cell types, immunoglobulin levels, and salivary gland output were similar for treated and control mice.

Discussion

Although endogenous CD40 is expressed in SG inflammatory foci in the SG of NOD mice, the expression of soluble CD40:Fc did not lead to reduced overall inflammation and/or improved salivary gland function. These data indicate possible redundancy of the CD40 pathway in the SG and suggests that targeting CD40 alone may not be sufficient to alter the disease phenotype.

A prospective, randomized, placebo-controlled study to identify biomarkers associated with active treatment in psoriatic arthritis: effects of adalimumab treatment on lesional and nonlesional skin

BACKGROUND

There is a need for biomarkers to screen the effectiveness of (novel) therapeutic agents for psoriasis at an early stage.

OBJECTIVE

We aimed to determine which of the changes in psoriatic skin correlates best with clinical improvement 4 weeks after effective adalimumab therapy.

METHODS

Twenty-two psoriatic arthritis patients were randomized to receive adalimumab or placebo. T cell numbers and markers of innate immunity were estimated in lesional and nonlesional skin biopsies at baseline and after 4 weeks of treatment.

RESULTS

CD161+ and elastase+ dermal cells in lesional skin were significantly reduced upon 4 weeks of successful adalimumab treatment compared with placebo.

CONCLUSION

Early improvement of psoriasis lesions during adalimumab therapy is associated with a marked reduction of infiltrated dermal CD161+ T cells and elastase+ neutrophils, suggesting that these parameters could be used as biomarkers to monitor early changes after active treatment in small proof-of-concept studies of short duration.

Genome-wide association analysis of anti-TNF drug response in patients with rheumatoid arthritis

BACKGROUND

Treatment strategies blocking tumour necrosis factor (anti-TNF) have proven very successful in patients with rheumatoid arthritis (RA). However, a significant subset of patients does not respond for unknown reasons. Currently, there are no means of identifying these patients before treatment. This study was aimed at identifying genetic factors predicting anti-TNF treatment outcome in patients with RA using a genome-wide association approach.

METHODS

We conducted a multistage, genome-wide association study with a primary analysis of 2 557 253 single-nucleotide polymorphisms (SNPs) in 882 patients with RA receiving anti-TNF therapy included through the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry and the database of Apotheekzorg. Linear regression analysis of changes in the Disease Activity Score in 28 joints after 14 weeks of treatment was performed using an additive model. Markers with p<10(-3) were selected for replication in 1821 patients from three independent cohorts. Pathway analysis including all SNPs with p<10(-3) was performed using Ingenuity.

RESULTS

772 markers showed evidence of association with treatment outcome in the initial stage. Eight genetic loci showed improved p value in the overall meta-analysis compared with the first stage, three of which (rs1568885, rs1813443 and rs4411591) showed directional consistency over all four cohorts studied. We were unable to replicate markers previously reported to be associated with anti-TNF outcome. Network analysis indicated strong involvement of biological processes underlying inflammatory response and cell morphology.

CONCLUSIONS

Using a multistage strategy, we have identified eight genetic loci associated with response to anti-TNF treatment. Further studies are required to validate these findings in additional patient collections.

The resolution of inflammation

In 2012, Nature Reviews Immunology organized a conference that brought together scientists and clinicians from both academia and industry to discuss one of the most pressing questions in medicine--how do we turn off rampant, undesirable inflammation? There is a growing appreciation that, similarly to the initiation of inflammation, the resolution of inflammation is an intricate and active process. Can we therefore harness the mediators involved in resolution responses to treat patients with chronic inflammatory or autoimmune diseases? Here, we ask five of the speakers from the conference to share their thoughts on this emerging field.

Enhanced costimulation by CD70+ B cells aggravates experimental autoimmune encephalomyelitis in autoimmune mice

OBJECTIVE

Assess whether CD70+ B cells contribute to EAE.

MATERIALS AND METHODS

MOG-specific TCR transgenic mice (2D2) were crossed with mice with constitutive CD70 expression on B cells. The development of EAE and the phenotype of B-T lymphocytes were studied in 2D2xCD70 animals.

RESULTS

Spontaneous EAE developed in 20% of 2D2xCD70 and 3% of 2D2 mice. EAE was also more severe in 2D2xCD70 versus 2D2 animals upon MOG immunization. The susceptibility of 2D2xCD70 to EAE was associated with fewer FoxP3+ T cells.

CONCLUSIONS

Expression of CD70 by B cells aggravates EAE possibly by reducing the number of regulatory T cells.

Smoking and overweight determine the likelihood of developing rheumatoid arthritis

Objectives

Rheumatoid arthritis (RA) is a prototypic chronic inflammatory disease with a debilitating course if untreated. A genetic predisposition for RA is known, and its occurrence is associated with the presence of autoantibodies in the serum and with environmental factors. It is unknown if smoking and overweight are contributory factors for developing RA in individuals with RA-specific autoantibodies in the serum.

Methods

Fifty-five individuals at risk for developing RA, based on the presence of RA-specific autoantibodies in the serum, who never had any evidence of arthritis upon physical examination, were followed over time. Smoking was assessed as being never or ever smoker and body mass index as <25 (normal) or ≥25 kg/m² (overweight). Clinical endpoint was the occurrence of arthritis. Proportional hazard regression analysis was performed to investigate the potential of (combinations of) variables in predicting the onset of arthritis over time.

Results

After a median follow up time of 13 (IQR 6–27) months, 15 individuals (27%) developed arthritis. Smoking was associated with the development of arthritis (HR (95% CI): 9.6 (1.3 to 73.0); p=0.029). Overweight was, independently of smoking, associated with arthritis (HR (95% CI): 5.6 (1.3 to 25.0); p=0.023). The overall arthritis risk of 28% after a median of 27 months follow up increased to 60% in individuals with a smoking history combined with overweight.

Conclusions

This is the first prospective study showing that smoking and overweight increase the risk of development of arthritis in a cohort of autoantibody-positive individuals at risk for developing RA. These results show the importance of life style factors in development of RA and should be critically evaluated in future clinical research aimed at disease prevention.

Expression of IL-20 in synovium and lesional skin of patients with psoriatic arthritis: differential response to alefacept treatment

Introduction

Psoriatic arthritis (PsA) is an inflammatory joint disease associated with psoriasis. Alefacept (a lymphocyte function-associated antigen (LFA)-3 Ig fusion protein that binds to CD2 and functions as an antagonist to T-cell activation) has been shown to result in improvement in psoriasis but has limited effectiveness in PsA. Interleukin-20 (IL-20) is a key proinflammatory cytokine involved in the pathogenesis of psoriasis. The effects of alefacept treatment on IL-20 expression in the synovium of patients with psoriasis and PsA are currently unknown.

Methods

Eleven patients with active PsA and chronic plaque psoriasis were treated with alefacept (7.5 mg per week for 12 weeks) in an open-label study. Skin biopsies were taken before and after 1 and 6 weeks, whereas synovial biopsies were obtained before and 4 and 12 weeks after treatment. Synovial biopsies from patients with rheumatoid arthritis (RA) (n = 10) were used as disease controls. Immunohistochemical analysis was performed to detect IL-20 expression, and stained synovial tissue sections were evaluated with digital image analysis. Double staining was performed with IL-20 and CD68 (macrophages), and conversely with CD55 (fibroblast-like synoviocytes, FLSs) to determine the phenotype of IL-20-positive cells in PsA synovium. IL-20 expression in skin sections (n = 6) was analyzed semiquantitatively.

Results

IL-20 was abundantly expressed in both PsA and RA synovial tissues. In inflamed PsA synovium, CD68⁺ macrophages and CD55⁺ FLSs coexpressed IL-20, and its expression correlated with the numbers of FLSs. IL-20 expression in lesional skin of PsA patients decreased significantly (P = 0.04) 6 weeks after treatment and correlated positively with the Psoriasis Area and Severity Index (PASI). IL-20 expression in PsA synovium was not affected by alefacept.

Conclusions

Conceivably, the relatively limited effectiveness of alefacept in PsA patients (compared with anti-tumor necrosis factor (TNF) therapy) might be explained in part by persistent FLS-derived IL-20 expression.

Safety and efficacy of ocrelizumab in patients with rheumatoid arthritis and an inadequate response to at least one tumor necrosis factor inhibitor: results of a forty-eight–week randomized, double-blind, placebo-controlled, parallel-group phase III trial

OBJECTIVE

To evaluate the safety and efficacy of ocrelizumab plus methotrexate (MTX) or leflunomide (LEF) in patients with active rheumatoid arthritis (RA) and an inadequate response to tumor necrosis factor α inhibitors.

METHODS

This was a multicenter randomized, double-blind, placebo-controlled, parallel-group study that continued over 48 weeks. Patients receiving stable doses of MTX or LEF were randomized to receive 2 infusions of placebo (n = 277), ocrelizumab 200 mg (n = 278), or ocrelizumab 500 mg (n = 285) on days 1 and 15 as well as at weeks 24 and 26. Coprimary end points were the proportion of patients with response according to the American College of Rheumatology 20% improvement criteria (ACR20) at weeks 24 and 48. Secondary end points included the change from baseline in the modified Sharp/van der Heijde score (SHS) and the ACR50/70 responses.

RESULTS

ACR20 responses were 22.0% in the placebo group, 42.2% in the ocrelizumab 200 mg group, and 47.9% in the ocrelizumab 500 mg group at 24 weeks and 19.5%, 48.7%, and 50.7%, respectively, at 48 weeks (P < 0.0001 versus placebo for each comparison at each time point). At 48 weeks, patients receiving both doses of ocrelizumab showed significantly improved ACR50 and ACR70 responses of ~3-fold versus placebo. Only those in the ocrelizumab 500 mg group showed statistically significant (P = 0.0017) inhibition of joint damage progression (mean change in the SHS) relative to placebo (61% inhibition) at 48 weeks. Overall adverse events and infections during the 48 weeks of study were comparable in all treatment groups. Serious infections were observed more frequently in patients taking ocrelizumab (5.1% and 4.3%) than in those taking placebo (2.5%).

CONCLUSION

Patients in both of the ocrelizumab groups met the clinical primary efficacy end points. Inhibition of change in the SHS was statistically significant at 48 weeks for those in the ocrelizumab 500 mg group. The rate of serious infections in this trial was higher for both ocrelizumab doses as compared with placebo.

Anti-TNF treatment blocks the induction of T cell-dependent humoral responses

OBJECTIVE

Experimental and human data suggest that tumour necrosis factor (TNF) blockade may affect B cell responses, in particular the induction of T cell-dependent (TD) humoral immunity. This study aimed to assess this hypothesis directly in patients with arthritis by analysing longitudinally the effect of TNF blockade on B cell activation and the maturation of humoral responses against TD and T cell-independent vaccines.

MATERIALS AND METHODS

Peripheral blood samples were obtained from 56 spondyloarthritis patients before and after treatment with either non-steroidal anti-inflammatory drug (NSAID) alone or TNF blockers and analysed for B cell activation, plasma cell differentiation, germinal centre versus extra-follicular B cell maturation, and somatic hypermutation. Vaccine responses to hepatitis B and Streptococcus pneumoniae were measured by ELISA.

RESULTS

TNF blockade augmented B cell activation as reflected by the expression of early activation markers, CD40, and costimulatory molecules, without affecting differentiation towards plasmablasts. This was associated with a specific increase of the unswitched fraction of circulating memory B cells and a decreased level of somatic hypermutation in anti-TNF treated patients, indicating an impairment of the germinal centre-dependent B cell maturation. In agreement with these findings, TNF blockade profoundly suppressed the response to the TD vaccination against hepatitis B, whereas the T cell-independent response against pneumococcal polysaccharides was only modestly affected.

CONCLUSIONS

These data indicate that TNF blockade severely impedes the induction of primary TD humoral responses, probably by interfering with the germinal centre reaction.

Signal transduction pathways in chronic inflammatory autoimmune disease: small GTPases

Ras superfamily small GTPases represent a wide and diverse class of intracellular signaling proteins that are highly conserved during evolution. These enzymes serve as key checkpoints in coupling antigen receptor, growth factor, cytokine and chemokine stimulation to cellular responses. Once activated, via their ability to regulate multiple downstream signaling pathways, small GTPases amplify and diversify signaling cascades which regulate cellular proliferation, survival, cytokine expression, trafficking and retention. Small GTPases, particularly members of the Ras, Rap, and Rho family, critically coordinate the function and interplay of immune and stromal cells during inflammatory respones, and increasing evidence indicates that alterations in small GTPase signaling contribute to the pathological behavior of these cell populations in human chronic inflammatory diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Here, we review how Ras, Rap, and Rho family GTPases contribute to the biology of cell populations relevant to human chronic inflammatory disease, highlight recent advances in understanding how alterations in these pathways contribute to pathology in RA and SLE, and discuss new therapeutic strategies that may allow specific targeting of small GTPases in the clinic.

Timing the therapeutic window of opportunity in early rheumatoid arthritis: proposal for definitions of disease duration in clinical trials

The effects of treatment in early rheumatoid arthritis (RA) and the consequences of delayed therapy represent important areas for research. The concept of a 'window of opportunity' is now well established and considerable attention has been paid to when it might close. However, in order to study how long the window of opportunity lasts, the timing of its opening must be precisely defined. An analysis of definitions of 'onset' in clinical studies reveals imprecision and heterogeneity, making accurate assessment of this important concept of the 'window of opportunity' very difficult. In this paper we propose that, in clinical trials in early RA, data on durations since onset of symptoms and onset of joint swelling as well as disease duration based on fulfilment of classification criteria should be routinely presented.

Impact of intravenous abatacept on synovitis, osteitis and structural damage in patients with rheumatoid arthritis and an inadequate response to methotrexate: the ASSET randomised controlled trial

Objectives

This randomised, double-blind, placebo-controlled phase IIIb study evaluated the impact of abatacept on MRI pathology as a primary outcome in methotrexate (MTX)-refractory patients with rheumatoid arthritis.

Methods

Patients received intravenous abatacept (∼10 mg/kg) or placebo, on background MTX, for 4 months, followed by an 8-month open-label extension (OLE; all patients received abatacept plus MTX). Patients had 1.5T MRI with intravenous contrast at baseline, Months 4 and 12; wrist synovitis (three locations assessed), and wrist and hand (15 and eight locations assessed, respectively) osteitis and erosion were scored using OMERACT-RAMRIS.

Results

26/27 abatacept- and 23/23 placebo-randomised patients completed Month 4 and entered the OLE; 26 and 21 completed Month 12. The primary endpoint was not achieved; mean change (SD) from baseline in synovitis was −0.44 (1.47) for abatacept versus 0.52 (1.38) for placebo (p=0.103) at Month 4. For mean change in synovitis adjusted for baseline score (sensitivity analysis), the difference between groups was −0.69, p=0.078. Adjusted mean changes (SE) in osteitis and erosion were −1.94 (0.86) and 0.45 (0.43) for abatacept, and 1.54 (0.90) and 0.95 (0.45) for placebo. Further MRI improvements were observed up to Month 12 for abatacept and from Months 4 to 12 for placebo-treated patients switched to abatacept at Month 4. Clinical efficacy was shown with abatacept and sustained to Month 12.

Conclusions

Despite small patient numbers, MRI detected structural and synovial benefit, sustained to Month 12 in abatacept+MTX-treated patients, and improvements in structural and inflammatory outcomes for placebo+MTX-treated patients following addition of abatacept.

Clinical trial registration

Clinicaltrials.gov NCT00420199.

Angiopoietin-2 promotes inflammatory activation of human macrophages and is essential for murine experimental arthritis

BACKGROUND

Angiopoietin (Ang)-1 and Ang-2, and their shared receptor Tie2, are expressed in rheumatoid arthritis (RA) synovial tissue, but the cellular targets of Ang signalling and the relative contributions of Ang-1 and Ang-2 to arthritis are poorly understood.

OBJECTIVES

To determine the cellular targets of Ang signalling in RA synovial tissue, and the effects of Ang-2 neutralisation in murine collagen-induced arthritis (CIA).

METHODS

RA and psoriatic arthritis (PsA) synovial biopsies were examined for expression of Tie2 and activated phospho (p)-Tie2 by quantitative immunohistochemistry and immunofluorescent double staining. Human monocyte and macrophage Tie2 expression was determined by flow cytometry and quantitative PCR. Regulation of macrophage intracellular signalling pathways and gene expression were examined by immunoblotting and ELISA. CIA was assessed in mice treated with saline, control antibody, prednisolone or neutralising anti-Ang-2 antibody.

RESULTS

Expression of synovial Tie2 and p-Tie2 was similar in RA and PsA. Tie2 activation in RA patient synovial tissue was predominantly localised in synovial macrophages and was expressed by human macrophage. Ang-1 and Ang-2 stimulated activation of multiple intracellular signalling pathways, and cooperated with tumour necrosis factor to induce macrophage interleukin 6 and macrophage inflammatory protein 1α production. Ang-2 selectively suppressed macrophage thrombospondin-2 production. Ang-2 neutralisation significantly decreased disease severity, synovial inflammation, neo-vascularisation and joint destruction in established CIA.

CONCLUSIONS

The authors identify synovial macrophages as primary targets of Ang signalling in RA, and demonstrate that Ang-2 promotes the pro-inflammatory activation of human macrophages. Ang-2 makes requisite contributions to pathology in CIA, indicating that targeting Ang-2 may be of therapeutic benefit in the treatment of RA.

Effect of baseline rheumatoid factor and anticitrullinated peptide antibody serotype on rituximab clinical response: a meta-analysis

BACKGROUND

Studies examining the relationship between serological status (rheumatoid factor and/or anticitrullinated antibody) and rituximab treatment outcome in rheumatoid arthritis (RA) have been hampered by limited numbers of seronegative patients.

OBJECTIVE

To carry out a meta-analysis of trials from the rituximab RA clinical programme to investigate this relationship further.

METHODS

This was a meta-analysis of four placebo-controlled, phase II or III clinical trials. The efficacy end point in all analyses was change from baseline in Disease Activity Score in 28 joints-erythrocyte sedimentation rate (DAS28-ESR) at 24 weeks. Assay of serotype and missing data imputation methods were consistent across all studies.

RESULTS

The population analysed comprised 2177 patients (rituximab, n=1416; placebo, n=761). Demographics and baseline disease characteristics were well balanced. When a fixed-effects meta-analysis approach was used, the overall-effect model indicated evidence of additional treatment benefit with rituximab in seropositive patients: reduction in DAS28-ESR at week 24 was on average 0.35 units (95% CI 0.12 to 0.84; n=1394) greater than in seronegative patients; this effect was not seen in placebo patients. Heterogeneity indices indicated significant uncertainty in the overall-effect model (Q=8.8, I=0.77; p=0.03 (χ(2) test)). Baseline Health Assessment Questionnaire score, pain visual analogue scale, swollen joint counts of 28 joints and race were significant contributors to this heterogeneity, with additional analysis indicating that these effects may predominate in early RA (methotrexate-naïve) populations. A dominant effect was seen in patients for whom one or more tumour necrosis factor inhibitors had failed.

CONCLUSION

Although the difference was modest, the overall-effect model indicates that seropositive patients respond better to rituximab than seronegative patients.

Chemokine receptor CCR1 antagonist CCX354-C treatment for rheumatoid arthritis: CARAT-2, a randomised, placebo controlled clinical trial

OBJECTIVES

CCX354-C is a specific, orally administered antagonist of the C-C chemokine receptor 1, which regulates migration of monocytes and macrophages to synovial tissue. This clinical trial evaluated the safety and efficacy of CCX354-C in patients with rheumatoid arthritis (RA).

METHODS

CARAT-2 is a 12-week double-blind, randomised, placebo controlled trial in 160 patients with RA, with 68 tender joint count and 66 swollen joint count ≥8 and C-reactive protein (CRP) >5 mg/l, despite being on methotrexate for at least 16 weeks. Subjects received placebo, CCX354-C 100 mg twice daily, or 200 mg once daily for 12 weeks. Endpoints included safety (primary) and RA disease activity assessments based on American College of Rheumatology (ACR) response, and changes in 28-joint disease activity score-CRP, individual ACR components, as well as soluble bone turnover markers.

RESULTS

CCX354-C was generally well tolerated by study subjects. The ACR20 response at week 12 was 39% in the placebo group, 43% in the 100 mg twice daily group (difference and 95% CI compared with placebo, 4.5 (-14.1 to 23.1); p=0.62) and 52% in the 200 mg once daily group (13.0 (-5.8 to 31.8); p=0.17) in the intention-to-treat population, and 30% in the placebo group, 44% in the 100 mg twice daily group (14.4 (-5.9 to 34.8); p=0.17), and 56% in the 200 mg once daily group (25.8 (5.3 to 46.4); p=0.01) in the prespecified population of patients satisfying CRP and joint count eligibility criteria at the screening and day 1 (predose) visits.

CONCLUSIONS

CCX354-C exhibited a good safety and tolerability profile and evidence of clinical activity in RA.

Triggering of the dsRNA sensors TLR3, MDA5, and RIG-I induces CD55 expression in synovial fibroblasts

BACKGROUND

CD55 (decay-accelerating factor) is a complement-regulatory protein highly expressed on fibroblast-like synoviocytes (FLS). CD55 is also a ligand for CD97, an adhesion-type G protein-coupled receptor abundantly present on leukocytes. Little is known regarding the regulation of CD55 expression in FLS.

METHODS

FLS isolated from arthritis patients were stimulated with pro-inflammatory cytokines and Toll-like receptor (TLR) ligands. Transfection with polyinosinic-polycytidylic acid (poly(I:C)) and 5'-triphosphate RNA were used to activate the cytoplasmic double-stranded (ds)RNA sensors melanoma differentiation-associated gene 5 (MDA5) and retinoic acid-inducible gene-I (RIG-I). CD55 expression, cell viability, and binding of CD97-loaded beads were quantified by flow cytometry.

RESULTS

CD55 was expressed at equal levels on FLS isolated from patients with rheumatoid arthritis (RA), osteoarthritis, psoriatic arthritis and spondyloarthritis. CD55 expression in RA FLS was significantly induced by IL-1β and especially by the TLR3 ligand poly(I:C). Activation of MDA5 and RIG-I also enhanced CD55 expression. Notably, activation of MDA5 dose-dependently induced cell death, while triggering of TLR3 or RIG-I had a minor effect on viability. Upregulation of CD55 enhanced the binding capacity of FLS to CD97-loaded beads, which could be blocked by antibodies against CD55.

CONCLUSIONS

Activation of dsRNA sensors enhances the expression of CD55 in cultured FLS, which increases the binding to CD97. Our findings suggest that dsRNA promotes the interaction between FLS and CD97-expressing leukocytes.

Adding tocilizumab or switching to tocilizumab monotherapy in methotrexate inadequate responders: 24-week symptomatic and structural results of a 2-year randomised controlled strategy trial in rheumatoid arthritis (ACT-RAY)

Objective

In patients with active rheumatoid arthritis (RA) despite methotrexate, to compare the efficacy of adding tocilizumab to that of switching to tocilizumab monotherapy.

Methods

Double-blind, 2-year study in which adults with active RA (DAS28 >4.4) despite methotrexate were randomly assigned either to continue methotrexate with the addition of tocilizumab (MTX+TCZ) 8 mg/kg every 4 weeks or switch to tocilizumab and placebo (TCZ+PBO). The primary endpoint was the DAS28–erythrocyte sedimentation rate (ESR) remission rate at week 24. Secondary objectives included other symptomatic outcomes, quality of life and progression of structural damage.

Results

Of 556 randomly assigned patients, 512 (92%) completed 24 weeks. DAS28–ESR remission rates were 40.4% for TCZ+MTX and 34.8% for TCZ+PBO (p=0.19); American College of Rheumatology 20/50/70/90 rates were 71.5%/45.5%/24.5%/5.8% (TCZ+MTX) and 70.3%/40.2%/25.4%/5.1% (TCZ+PBO; differences not significant). A significant difference between groups was seen for low DAS28 (61.7% vs 51.4%). Radiographic progression was small and not different between groups (Genant–Sharp score progression ≤ smallest detectable change in 91% (TCZ+MTX) and 87% (TCZ+PBO)). Rates per 100 patient-years of serious adverse events and serious infections were 21 and six, respectively, for TCZ+MTX and 18 and six, respectively, for TCZ+PBO. Alanine aminotransferase elevations greater than threefold the upper limit of normal occurred in 7.8% and 1.2% of TCZ+MTX and TCZ+PBO patients, respectively.

Conclusion

No clinically relevant superiority of the TCZ+MTX add-on strategy over the switch to tocilizumab monotherapy strategy was observed. The combination was more commonly associated with transaminase increases. Meaningful clinical and radiographic responses were achieved with both strategies, suggesting that tocilizumab monotherapy might be a valuable treatment strategy in suitable RA patients.

The expression of APRIL in Sjogren's syndrome: aberrant expression of APRIL in the salivary gland

OBJECTIVE

A proliferation-inducing ligand (APRIL) and B-cell activating factor (BAFF) are B-cell-related mediators and may play a role in the pathogenesis in SS. In this descriptive study we assessed the expression of APRIL and BAFF in the minor salivary gland and serum from SS patients.

METHODS

Paraffin-embedded minor salivary gland sections from SS patients, non-SS controls and healthy volunteers were analysed by immunohistochemistry. Digital image quantification was performed to evaluate the expression of BAFF, APRIL and transmembrane activator and CAML interactor. Furthermore, serum was analysed for soluble BAFF and APRIL levels by ELISA. All the data were also analysed for subjects with decreased and normal stimulated salivary flow independent of the classification.

RESULTS

APRIL expression was lower in minor salivary gland biopsies from SS patients compared with healthy volunteers and to a lesser extent non-SS controls, whereas BAFF expression was similar in all groups. Soluble APRIL levels in serum were increased in SS patients and in subjects with decreased salivary flow independent of the classification.

CONCLUSION

APRIL salivary gland tissue levels are decreased, suggesting that targeting this cytokine locally in the salivary glands would not benefit SS patients. Moreover, the discrepancy between local and systemic levels is striking and future research should assess this in more detail.

The features of the synovium in early rheumatoid arthritis according to the 2010 ACR/EULAR classification criteria

Objectives

It has been shown in early arthritis cohorts that the 2010 ACR/EULAR criteria for rheumatoid arthritis (RA) enable an earlier diagnosis, perhaps at the cost of a somewhat more heterogeneous patient population. We describe the features of synovial inflammation in RA patients classified according to these new criteria.

Methods

At baseline, synovial tissue biopsy samples were obtained from disease-modifying antirheumatic drug (DMARD)-naïve early RA patients (clinical signs and symptoms <1 year). Synovial tissue was analyzed for cell infiltration, vascularity, and expression of adhesion molecules. Stained sections were evaluated by digital image analysis. Patients were classified according to the two different sets of classification criteria, autoantibody status, and outcome.

Findings

Synovial tissue of 69 RA patients according to 2010 ACR/EULAR criteria was analyzed: 56 patients who fulfilled the criteria for RA at baseline and 13 who were initially diagnosed as undifferentiated arthritis but fulfilled criteria for RA upon follow up. The synovium at baseline was infiltrated by plasma cells, macrophages, and T cells as well as other cells, and findings were comparable to those when patients were selected based on the 1987 ACR criteria for RA. There was no clear cut difference in the characteristics of the synovium between RA patients initially diagnosed as undifferentiated arthritis and those who already fulfilled classification criteria at baseline.

Conclusion

The features of synovial inflammation are similar when the 2010 ACR/EULAR classification criteria are used compared to the 1987 ACR criteria.

Soluble immune complexes shift the TLR-induced cytokine production of distinct polarized human macrophage subsets towards IL-10

BACKGROUND

Costimulation of murine macrophages with immune complexes (ICs) and TLR ligands leads to alternative activation. Studies on human myeloid cells, however, indicate that ICs induce an increased pro-inflammatory cytokine production. This study aimed to clarify the effect of ICs on the pro- versus anti-inflammatory profile of human polarized macrophages.

MATERIALS AND METHODS

Monocytes isolated from peripheral blood of healthy donors were polarized for four days with IFN-γ, IL-4, IL-10, GM-CSF, M-CSF, or LPS, in the presence or absence of heat aggregated gamma-globulins (HAGGs). Phenotypic polarization markers were measured by flow cytometry. Polarized macrophages were stimulated with HAGGs or immobilized IgG alone or in combination with TLR ligands. TNF, IL-6, IL-10, IL-12, and IL-23 were measured by Luminex and/or RT-qPCR.

RESULTS

HAGGs did not modulate the phenotypic polarization and the cytokine production of macrophages. However, HAGGs significantly altered the TLR-induced cytokine production of all polarized macrophage subsets, with the exception of MΦ(IL-4). In particular, HAGGs consistently enhanced the TLR-induced IL-10 production in both classically and alternatively polarized macrophages (M1 and M2). The effect of HAGGs on TNF and IL-6 production was less pronounced and depended on the polarization status, while IL-23p19 and IL-12p35 expression was not affected. In contrast with HAGGs, immobilized IgG induced a strong upregulation of not only IL-10, but also TNF and IL-6.

CONCLUSION

HAGGs alone do not alter the phenotype and cytokine production of in vitro polarized human macrophages. In combination with TLR-ligands, however, HAGGs but not immobilized IgG shift the cytokine production of distinct macrophage subsets toward IL-10.

Intimal lining layer macrophages but not synovial sublining macrophages display an IL-10 polarized-like phenotype in chronic synovitis

INTRODUCTION

Synovial tissue macrophages play a key role in chronic inflammatory arthritis, but the contribution of different macrophage subsets in this process remains largely unknown. The main in vitro polarized macrophage subsets are classically (M1) and alternatively (M2) activated macrophages, the latter comprising interleukin (IL)-4 and IL-10 polarized cells. Here, we aimed to evaluate the polarization status of synovial macrophages in spondyloarthritis (SpA) and rheumatoid arthritis (RA).

METHODS

Expression of polarization markers on synovial macrophages, peripheral blood monocytes, and in vitro polarized monocyte-derived macrophages from SpA versus RA patients was assessed by immunohistochemistry and flow cytometry, respectively. The polarization status of the intimal lining layer and the synovial sublining macrophages was assessed by double immunofluorescence staining.

RESULTS

The expression of the IL-10 polarization marker cluster of differentiation 163 (CD163) was increased in SpA compared with RA intimal lining layer, but no differences were found in other M1 and M2 markers between the diseases. Furthermore, no significant phenotypic differences in monocytes and in vitro polarized monocyte-derived macrophages were seen between SpA, RA, and healthy controls, indicating that the differential CD163 expression does not reflect a preferential M2 polarization in SpA. More detailed analysis of intimal lining layer macrophages revealed a strong co-expression of the IL-10 polarization markers CD163 and cluster of differentiation 32 (CD32) but not any of the other markers in both SpA and RA. In contrast, synovial sublining macrophages had a more heterogeneous phenotype, with a majority of cells co-expressing M1 and M2 markers.

CONCLUSIONS

The intimal lining layer but not synovial sublining macrophages display an IL-10 polarized-like phenotype, with increased CD163 expression in SpA versus RA synovitis. These differences in the distribution of the polarized macrophage subset may contribute to the outcome of chronic synovitis.

Treatment-specific changes in circulating adipocytokines: a comparison between tumour necrosis factor blockade and glucocorticoid treatment for rheumatoid arthritis

Objective

There is increasing evidence that adipocytokines may exert proinflammatory and destructive effects in rheumatoid arthritis (RA). Hence, the authors investigated the relationship between adipocytokines and several features associated with RA (inflammation, joint destruction and cardiovascular disease), as well as the effect of treatment with a tumour necrosis factor inhibitor or glucocorticoids (GCs) hereupon.

Methods

Serum levels of adiponectin, leptin, resistin, visfatin, vaspin and lipids were determined in a well-defined cohort of patients with RA before and after 16 weeks of adalimumab treatment (adalimumab cohort). The same parameters were analysed in two other cohorts of patients with RA before and after 2 weeks of high-dose prednisolone (high GC cohort) and before and after 22 weeks of treatment with a combination regimen with tapered high-dose prednisolone (COBRA -GC cohort). Radiographs of hands and feet (adalimumab and COBRA-GC cohorts) were assessed at baseline and after treatment.

Results

Treatment with adalimumab or GC showed opposing effects on vaspin and visfatin levels. Lipid levels improved after several months of adalimumab or GC treatment; in the adalimumab cohort, this was related to reduced visfatin levels, independent of C reactive protein levels. After long-term adalimumab or GC treatment, resistin levels declined, which was associated with a decrease in inflammation markers. In the adalimumab cohort, baseline resistin levels were predictive of baseline radiological damage, independent of anticitrullinated peptide antibodies status or C reactive protein levels.

Conclusion

Changes in serum adipocytokine levels were treatment specific, further strengthening the role of visfatin and resistin in several disease manifestations of RA.

EULAR recommendations for terminology and research in individuals at risk of rheumatoid arthritis: report from the Study Group for Risk Factors for Rheumatoid Arthritis

The Study Group for Risk Factors for Rheumatoid Arthritis was established by the EULAR Standing Committee on Investigative Rheumatology to facilitate research into the preclinical and earliest clinically apparent phases of rheumatoid arthritis (RA). This report describes the recommendation for terminology to be used to define specific subgroups during different phases of disease, and defines the priorities for research in this area. Terminology was discussed by way of a three-stage structured process: A provisional list of descriptors for each of the possible phases preceding the diagnosis of RA were circulated to members of the study group for review and feedback. Anonymised comments from the members on this list were fed back to participants before a 2-day meeting. 18 participants met to discuss these data, agree terminologies and prioritise important research questions. The study group recommended that, in prospective studies, individuals without RA are described as having: genetic risk factors for RA; environmental risk factors for RA; systemic autoimmunity associated with RA; symptoms without clinical arthritis; unclassified arthritis; which may be used in a combinatorial manner. It was recommended that the prefix 'pre-RA with:' could be used before any/any combination of the five points above but only to describe retrospectively a phase that an individual had progressed through once it was known that they have developed RA. An approach to dating disease onset was recommended. In addition, important areas for research were proposed, including research of other tissues in which an adaptive immune response may be initiated, and the identification of additional risk factors and biomarkers for the development of RA, its progression and the development of extra-articular features. These recommendations provide guidance on approaches to describe phases before the development of RA that will facilitate communication between researchers and comparisons between studies. A number of research questions have been defined, requiring new cohorts to be established and new techniques to be developed to image and collect material from different sites.

Characteristics of synovial inflammation in early arthritis analysed by pixel-by-pixel time-intensity curve shape analysis

OBJECTIVE

Dynamic contrast-enhanced (DCE-MRI) time-intensity curve (TIC) shape analysis has previously been used in oncology, where fast initial enhancement and early washout are associated with malignancy. As RA synovium has some tumour-like features, we investigated DCE-MRI TIC shape expression in early arthritis in relationship to diagnosis.

METHODS

Twenty-eight DMARD-naïve, early arthritis patients (<1 year) with inflammation of at least one knee joint were included. At baseline DCE-MRI of the inflamed knee joint was performed, and the TIC shape type expression, maximal enhancement, maximum slope of increase and total volume of enhancing pixels were calculated. In addition, disease activity parameters were determined. At 2 years of follow-up, patients were classified as RA or non-RA according to established classification criteria.

RESULTS

Type 4 TIC shape, characterized by fast initial enhancement followed by a quick washout phase, was significantly higher in patients fulfilling classification criteria for RA after 2 years of follow-up compared with non-RA patients (15.6 and 7.9%, respectively, P = 0.02). All other DCE-MRI parameters showed no differences between the groups, highlighting the specificity of this observation.

CONCLUSION

A high expression of aggressive DCE-MRI TIC shape Type 4 is associated with RA. Our results are consistent with the view that increased vascularity plays a key role in the pathogenesis of RA. This study underlines the rationale for further studies investigating the prospect of DCE-MRI TIC shape analysis as a diagnostic tool in early arthritis and the relationship with development of destructive disease.