Involvement of matrix metalloproteinases and their inhibitors in peripheral synovitis and down-regulation by tumor necrosis factor ? blockade in spondylarthropathy

Matrix Metalloproteinases; A Biomarker of Disease Activity and Prognosis in Spondyloarthritis: A Narrative Review

BACKGROUND

Matrix metalloproteinases, as components of the proteolytic system, are deemed to be implicated in the pathogenesis and progression of several rheumatic diseases. Their role in spondyloarthritis has been investigated by several studies.

OBJECTIVE

This article aims to review and summarize the current knowledge related to metalloproteinases in patients with spondyloarthritis.

METHODS

To examine the association between matrix metalloproteinases and spondyloarthritis, we conducted a narrative review using a literature search in SCOPUS for English-language sources. The search included studies published from the database inception to December 2020.

RESULTS

A total number of 74 articles were included. It was found that levels of matrix metalloproteinases 3 were higher in radiographic axial spondyloarthritis patients and seemed to play a role in the progression of joint damage. The levels of matrix metalloproteinases 1, 2, and 9 were upregulated in psoriatic arthritis patients compared to psoriasis and could identify psoriasis patients who would develop rheumatic manifestations. The levels of matrix metalloproteinases correlated significantly with disease activity in ankylosing spondylitis and decreased upon treatment with Tumor Necrosis Factor inhibitors (TNFi).

CONCLUSION

Excessive matrix metalloproteinases activity is associated with articular destruction. Their levels can reflect disease activity, structural damage, and response to TNFi in patients with spondyloarthritis. Nevertheless, further studies are needed to confirm these results.

A2A adenosine receptor agonist reduced MMP8 expression in healthy M2-like macrophages but not in macrophages from ankylosing spondylitis patients

BACKGROUND

Ankylosing spondylitis (AS) is an inflammatory autoimmune disease that mostly affects different joints of the body. Macrophages are the predominant cells that mediate disease progression by secreting several pro-inflammatory mediators. Different receptors are involved in macrophages' function including the adenosine receptors (AR). Our main objective in this study was to assess the effect of applying A_2A adenosine receptor agonist (CGS-21,680) on the gene expression of inflammatory mediators including bone morphogenetic proteins (BMP)-2, 4 and matrix metalloproteinases (MMP)-3, 8, 9, and 13 on the macrophages from AS patients compared to healthy macrophages.

METHODS

Monocytes were isolated from the whole blood of 28 individuals (AS patients and healthy controls in a 1:1 ratio). Macrophages were differentiated using macrophage colony-stimulating factor (M-CSF), and flow cytometry was performed to confirm surface markers. CGS-21,680 was used to treat cells that had been differentiated. Using SYBR green real-time PCR, relative gene expression was determined.

RESULTS

Activating A_2AAR diminished MMP8 expression in healthy macrophages while it cannot reduce MMP8 expression in patients' macrophages. The effect of A_2AAR activation on the expression of BMP2 and MMP9 reached statistical significance neither in healthy macrophages nor in the patients' group. We also discovered a significant positive connection between MMP8 expression and patient scores on the Bath ankylosing spondylitis functional index (BASFI).

CONCLUSION

Due to the disability of A_2AAR activation in the reduction of MMP8 expression in patients' macrophages and the correlation of MMP8 expression with BASFI index in patients, these results represent defects and dysregulations in the related signaling pathway in patients' macrophages.

Extracellular matrix protein turnover markers are associated with axial spondyloarthritis-a comparison with postpartum women and other non-axial spondyloarthritis controls with or without back pain

Background

Axial spondyloarthritis (axSpA) is a common chronic inflammatory disease, associated with extracellular matrix (ECM) remodeling of the cartilage, bone, and connective tissues. The primary symptom of axSpA is back pain, caused by inflammation. However, there is a medical need to truly identify patients with axSpA from other subjects with buttock or low back pain attributable to other reasons. We aimed to investigate circulating biomarkers of ECM/inflammation (MMP-degraded type I (C1M), II (C2M, T2CM), III (C3M), IV (C4M), VI (C6M), and X (C10C, COL10NC) collagens, CRPM, PROM and VICM) and ECM formation of type II (PRO-C2), III (PRO-C3), IV (PRO-C4), and VI (PRO-C6) collagens as potential biomarkers to identify patients with axSpA.

Methods

We measured biomarkers from a cross-sectional study with 204 participants by enzyme-linked immunosorbent assay (ELISA). The study included axSpA patients (N = 41), women with postpartum buttock/pelvic pain (N = 46), disc herniation (N = 25), and a group of healthy subjects (including women without postpartum pelvic pain (N = 14), subjects with various types of physical strain (cleaning staff (N = 26) long-distance runners (N = 23)), and healthy men (N = 29)). Differences between the groups were calculated by ANCOVA and AUC, while Spearman’s correlations were performed with ECM biomarkers and clinical scores.

Results

Patients with axSpA expressed significantly higher levels of C1M, C4M, and VICM (p < 0.05-p < 0.0001) compared to all the non-axSpA control groups. Further, C6M and PRO-C4 were significantly higher in patients with axSpA (both p < 0.0001) compared to women with postpartum pelvic pain and healthy subjects, whereas PRO-C3 was significantly lower compared to healthy subjects (p = 0.01). The best ECM common biomarker to differentiate between axSpA and the non-axSpA control groups was PRO-C4 (AUC ≥ 0.75; specificity ≥ 0.79, sensitivity = 0.65). Mild correlations were observed between collagen turnover and inflammation biomarkers and CRP and MRI (ρ ≥ 0.3; p < 0.05-p < 0.001).

Conclusions

Biomarkers of type I, IV, and VI collagen and biomarkers of inflammation showed an altered turnover in patients with axSpA compared with the non-axSpA control groups. Such biomarkers may be useful in combination with MRI or independently to separate patients with axSpA from other back pain conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02839-1.

Downregulation of Tumour Necrosis Factor α Gene Expression in Peripheral Blood Mononuclear Cells Cultured in the Presence of Tofacitinib Prior to Therapy Is Associated with Clinical Remission in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by pain, synovial hyperplasia, mononuclear cell infiltration, bone erosion and joint destruction. Efficacy of personalized therapy in RA is associated with correct choice of therapeutic agent and a possibility to predict its effect prior to treatment. Our objective was to examine the association of baseline expression of metalloproteinase (MMP)-9 and cathepsin K, which are involved in cartilage and bone degradation, as well as proinflammatory cytokines tumour necrosis factor (TNF)α and interleukin (IL)-1β in the peripheral blood mononuclear cells (PBMCs) obtained from patients with RA cultured with tofacitinib (TFCN) and remission achievement. We examined 12 tofacitinib-naïve patients with RA, with a median age of 51 years and disease duration of 37.6 months. After three months of TFCN therapy, six of these patients reached clinical remission criteria while others preserved high and moderate disease activity. PBMCs were tested prior to therapy followed by their isolation in Ficoll density gradient and cultured with 100 nM TFCN for 48 h. Gene expression analysis for MMP-9, cathepsin K, IL-1β, and TNFα was performed with quantitative real-time RT-PCR using total RNA isolated from and cultured with TFCN PBMCs compared with untreated cells. Expression of all the examined genes was significantly upregulated in those cultured with TFCN PBMCs from patients who maintained high and moderate disease activity after TFCN therapy while TNFα gene expression was significantly downregulated in patients who gained remission compared with untreated counterparts. Downregulation of TNFα gene expression in PBMCs from TFCN-naïve patients with RA cultured with TFCN prior to therapy compared with untreated counterparts might serve a prognostic biomarker for remission attainment in response to tofacitinib therapy.

IL-12p40/IL-23p40 Blockade With Ustekinumab Decreases the Synovial Inflammatory Infiltrate Through Modulation of Multiple Signaling Pathways Including MAPK-ERK and Wnt

Background: Psoriatic arthritis (PsA) is a chronic inflammatory joint disease within the spondyloarthritis spectrum. IL-12p40/IL-23p40 blockade reduces PsA disease activity, but its impact on synovial inflammation remains unclear. Objectives: To investigate the cellular and molecular pathways affected by IL-12p40/IL-23p40 blockade with ustekinumab in the synovium of PsA patients. Methods: Eleven PsA patients with at least one inflamed knee or ankle joint were included in a 24-week single-center open-label study and received ustekinumab 45 mg/sc according to standard care at week 0, 4, and 16. Besides clinical outcomes, synovial tissue (ST) samples were obtained by needle arthroscopy from an inflamed knee or ankle joint at baseline, week 12 and 24 and analyzed by immunohistochemistry, RNA-sequencing and real-time quantitative polymerase chain reaction (qPCR). Results: We obtained paired baseline and week 12, and paired baseline, week 12 and 24 ST samples from nine and six patients, respectively. Eight patients completed 24 weeks of clinical follow-up. At 12 weeks 6/11 patients met ACR20, 2/11 met ACR50 and 1/11 met ACR70 improvement criteria, at 24 weeks this was 3/8, 2/8 and 1/8 patients, respectively. Clinical and serological markers improved significantly. No serious adverse events occurred. We observed numerical decreases of all infiltrating cell subtypes at week 12, reaching statistical significance for CD68+ sublining macrophages. For some cell types this was even more pronounced at week 24, but clearly synovial inflammation was incompletely resolved. IL-17A and F, TNF, IL-6, IL-8, and IL-12p40 were not significantly downregulated in qPCR analysis of W12 total biopsies, only MMP3 and IL-23p19 were significantly decreased. RNA-seq analysis revealed 178 significantly differentially expressed genes between baseline and 12 weeks (FDR 0.1). Gene Ontology and KEGG terms enrichment analyses identified overrepresentation of biological processes as response to reactive oxygen species, chemotaxis, migration and angiogenesis as well as MAPK-ERK and PI3K-Akt signaling pathways among the downregulated genes and of Wnt signaling pathway among the upregulated genes. Furthermore, ACR20 responders and non-responders differed strikingly in gene expression profiles in a post-hoc exploratory analysis. Conclusions: Ustekinumab suppresses PsA synovial inflammation through modulation of multiple signal transduction pathways, including MAPK-ERK, Wnt and potentially PI3K-Akt signaling rather than by directly impacting the IL-17 pathway.

Anti-IL-17A treatment reduces serum inflammatory, angiogenic and tissue remodeling biomarkers accompanied by less synovial high endothelial venules in peripheral spondyloarthritis

Spondyloarthritis (SpA) is characterized by inflammation and new bone formation. The exact pathophysiology underlying these processes remains elusive. We propose that the extensive neoangiogenesis in SpA could play a role both in sustaining/enhancing inflammation and in new bone formation. While ample data is available on effects of anti-TNF on angiogenesis, effects of IL-17A blockade on serum markers are largely unknown. We aimed to assess the impact of secukinumab (anti-IL-17A) on synovial neoangiogenesis in peripheral SpA, and how this related to changes in inflammatory and tissue remodeling biomarkers. Serum samples from 20 active peripheral SpA patients included in a 12 week open-label trial with secukinumab were analyzed for several markers of angiogenesis and tissue remodeling. Synovial biopsies taken before and after treatment were stained for vascular markers. Serum levels of MMP-3, osteopontin, IL-6 (all P < 0.001), IL-31, S100A8, S100A9, Vascular Endothelial Growth Factor A (VEGF-A), IL-33, TNF-α (all P < 0.05) decreased significantly upon anti-IL17A treatment. Secukinumab treatment resulted in a decrease in the number of synovial high endothelial venules and lymphoid aggregate score. These results indicate that anti-IL-17A not only diminishes inflammation, but also impacts angiogenesis and tissue remodeling/new bone formation. This may have important implications for disease progression and/or structural damage.

An update on serum biomarkers to assess axial spondyloarthritis and to guide treatment decision

Axial spondyloarthritis (axSpA) is a group of debilitating, chronic, rheumatic conditions characterized by inflammation and new bone formation, mainly involving the spine and the sacroiliac joints. The lack of biomarkers in axSpA is well known. Despite significant treatment advances in recent years thanks to the introduction of drugs with a new mode of action, such as new biologic and targeted synthetic disease-modifying antirheumatic drugs, no relevant improvement in the identification of disease biomarkers has been achieved. Common parameters, such as erythrocyte sedimentation rate and C-reactive protein, which are routinely used to measure systemic inflammation, are the sole markers available to date and are not adequate to assess disease activity in all patients. The aim of this study is to review the most promising serum biomarkers that may help treatment decision in axSpA via a proper assessment of disease activity and identification of negative prognostic factors.

Nanomedicine for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that results in severe inflammatory microenvironments in the joint tissues. In clinics, disease-modifying antirheumatic drugs (DMARDs) are generally prescribed to patients with RA, but their long-term use often shows toxicity in some organs such as the gastrointestinal system, skin, and kidneys and immunosuppression-mediated infection. Nanomedicine has emerged as a new therapeutic strategy to efficiently localize the drugs in inflamed joints for the treatment of RA. In this Review, we introduce recent research in the area of nanomedicine for the treatment of RA and discuss how the nanomedicine can be used to deliver therapeutic agents to the inflamed joints and manage the progression of RA, particularly focusing on targeted delivery, controlled drug release, and immune modulation.

Association study between matrix metalloproteinase-3 gene (MMP3) polymorphisms and ankylosing spondylitis susceptibility

BACKGROUND

Ankylosing spondylitis (AS) is the second most common cause of inflammatory arthritis worldwide affecting the axial skeleton. Single nucleotide polymorphisms (SNPs) of matrix metalloproteinase-3 (MMP3) in the development of AS has few been investigated in Chinese population.

METHODS

A total of 362 patients with AS and 362 healthy controls were enrolled in the study. Five SNPs in MMP3 genotypes were identified by Agena MassARRAY. Chi-squared tests and genetic model were used to evaluate associations.

RESULTS

rs522616 had a significant risk of AS development compared to those with the TT genotype (p = 0.008). By multiple logistic regression models analysis, in codominant model, rs522616 CT genotypes also had a 1.44-fold risk (95% CI = 1.06-1.96, p = 0.008) for AS development compared to those with TT genotypes. In recessive model, the CC genotypes was a significantly reduced AS risk for individuals with TT/CT genotype (OR = 0.64; 95% CI = 0.41-0.99, p = 0.040).

CONCLUSION

The present study suggests that MMP3 rs522616 polymorphism is associated with AS susceptibility and MMP3 might be a potential diagnostic biomarker for AS. Further independent studies with larger cohorts are warranted to validate our findings in different populations.

Pharmacodynamic Monitoring of Biological Therapies in Chronic Inflammatory Diseases

BACKGROUND

Psoriasis, psoriatic arthritis, spondyloarthritis, rheumatoid arthritis, ulcerative colitis, and Crohn disease share similar underlying pathophysiological processes, providing the opportunity to treat the patients using similar biological therapies. Failure of biological treatments due to underexposure can be managed by therapeutic drug monitoring. Adjusting the treatment based on pharmacokinetic monitoring can be further improved by taking pharmacodynamic parameters such as clinical and molecular markers into account.

METHODS

Here, we critically evaluate the existing evidence, the hurdles to be taken, and the opportunities for a widespread implementation of pharmacodynamic monitoring.

RESULTS

Pharmacodynamic monitoring typically is the monitoring of biochemical markers. A pharmacodynamic marker preferably is specific for the pharmacological action of a drug, but most of the time nonspecific pharmacodynamic markers are used, such as C-reactive protein and the erythrocyte sedimentation rate. Clinical pharmacodynamic markers typically evaluate physical variables or symptoms. Although physician-reported outcomes have been studied for a longer time and often have been shown to correlate well with molecular pharmacodynamic markers and treatment outcomes, the introduction of mobile health or mHealth technologies caused a shift toward patient-reported outcomes, with the associated challenge to consistently reflect the inflammatory state, thereby preventing undertreatment or unnecessary overdosing of patients.

CONCLUSIONS

The primary goal of pharmacodynamic monitoring is to optimize the response, but it can also have an impact on safety, costs, patient adherence, etc. Ideally, the constant remote monitoring of patient-reported disease activity is expected to become the standard, facilitated by mHealth technologies.

Hepatocyte growth factor is a potential biomarker for osteoproliferation and osteoporosis in ankylosing spondylitis

We explored relations between serum hepatocyte growth factor (HGF), disease activity, osteoproliferation, and bone mineral density (BMD) in ankylosing spondylitis (AS), in comparison with healthy controls. HGF was increased especially in male AS patients and smokers and associated with both lower BMD and more chronic radiographic changes in the spine.

INTRODUCTION

Ankylosing spondylitis (AS) is characterized by both osteoproliferation and increased bone loss. Biomarkers are requested to predict the processes. The aims of this study were to compare serum levels of hepatocyte growth factor (HGF), matrix metalloproteinase-3 (MMP-3), and vascular endothelial growth factor (VEGF) in AS patients with healthy controls (HC) and to explore the associations with disease activity, osteoproliferation, and bone mineral density (BMD).

METHODS

Serum from AS patients (modified NY-criteria) and HC was analyzed for HGF, MMP-3, and VEGF with ELISA. Disease activity parameters were collected. Osteoproliferation was assessed with modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and BMD was measured in femoral neck.

RESULTS

Totally, 204 AS patients and 80 sex and age matched HC were included. Serum HGF was higher in the AS patients compared with the HC, whereas serum MMP-3 and VEGF were not. Serum HGF was also higher in smokers and in the male AS patients positively correlated with age, BASMI, and mSASSS, and negatively correlated with BMD. The biomarkers were all positively associated with ESR, CRP, and WBC. In multiple linear regression analysis serum HGF remained associated with higher mSASSS and lower BMD, after adjusting for age, sex, CRP, smoking, and body mass index.

CONCLUSIONS

Serum HGF was increased in male AS patients and associated with higher mSASSS and lower BMD. In addition, serum HGF was positively associated with risk factors for osteoproliferation such as age, CRP and smoking. HGF could be a potential biomarker of importance for the bone metabolism in AS.

TRIAL REGISTRATION

NCT00858819.

Brief Report: Interleukin-17 Blockade With Secukinumab in Peripheral Spondyloarthritis Impacts Synovial Immunopathology Without Compromising Systemic Immune Responses

OBJECTIVE

Secukinumab (anti-interleukin-17A [anti-IL-17A]) is an effective therapy for ankylosing spondylitis and psoriatic arthritis, the prototypical forms of spondyloarthritis (SpA). We undertook this study to determine whether secukinumab modulates the immunopathology of target lesions without blunting systemic immune responses, using peripheral SpA as a model.

METHODS

Twenty patients with active peripheral SpA were included in a 12-week open-label trial with secukinumab (300 mg once weekly from baseline to week 4 and then every 4 weeks thereafter). Outcomes included clinical response, cytokine production by peripheral blood cells using TruCulture technology, and histologic and real-time quantitative polymerase chain reaction analysis of synovial biopsy samples before and after treatment.

RESULTS

All patients completed the 12-week study without severe adverse events (AEs) or severe treatment-related AEs. The efficacy end point, the number of patients meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) at 12 weeks, was achieved by 13 of the 20 patients, of whom 8 achieved an ACR50 response and 5 achieved an ACR70 response, with rapid and significant improvements in all clinical disease activity measures. Clinical improvement in joint counts was associated with a histologic decrease in synovial sublining macrophages (P = 0.028) and neutrophils (P = 0.004), both of which are sensitive synovial biomarkers of inflammatory response in peripheral SpA, as well as with decreased synovial expression of IL-17A messenger RNA (mRNA) (P = 0.010) but not of tumor necrosis factor mRNA. Systemically, secukinumab treatment decreased the C-reactive protein level and the erythrocyte sedimentation rate (both P < 0.01), and also decreased matrix metalloproteinase 3 production in the TruCulture system (P < 0.05). However, with the exception of IL-17A itself, the capacity of peripheral blood cells to produce a broad panel of cytokines and chemokines upon stimulation with microbial antigens was not affected.

CONCLUSION

This mechanism-of-action study in peripheral SpA indicates that clinical improvement with secukinumab treatment is paralleled by immunomodulation of inflamed target tissues without compromising systemic immune responses.

Proteinases and their receptors in inflammatory arthritis: an overview

Proteinases are enzymes with established roles in physiological and pathological processes such as digestion and the homeostasis, destruction and repair of tissues. Over the past few years, the hormone-like properties of circulating proteinases have become increasingly appreciated. Some proteolytic enzymes trigger cell signalling via proteinase-activated receptors, a family of G protein-coupled receptors that have been implicated in inflammation and pain in inflammatory arthritis. Proteinases can also regulate ion flux owing to the cross-sensitization of transient receptor potential cation channel subfamily V members 1 and 4, which are associated with mechanosensing and pain. In this Review, the idea that proteinases have the potential to orchestrate inflammatory signals by interacting with receptors on cells within the synovial microenvironment of an inflamed joint is revisited in three arthritic diseases: osteoarthritis, spondyloarthritis and rheumatoid arthritis. Unanswered questions are highlighted and the therapeutic potential of modulating this proteinase-receptor axis for the management of disease in patients with these types of arthritis is also discussed.

Serum bone-turnover biomarkers are associated with the occurrence of peripheral and axial arthritis in psoriatic disease: a prospective cross-sectional comparative study

Background

A recent systematic review identified four candidate serum-soluble bone-turnover biomarkers (dickkopf-1, Dkk-1; macrophage-colony stimulating factor, M-CSF; matrix metalloproteinase-3, MMP-3; osteoprotegerin, OPG) showing possible association with psoriatic arthritis (PsA). We aimed to: (i) confirm and determine if these four biomarkers are associated with PsA; (ii) differentiate psoriasis cases with and without arthritis; and (iii) differentiate PsA cases with and without axial arthritis.

Methods

A prospective cross-sectional comparative two-centre study recruited 200 patients with psoriasis without arthritis (PsC), 127 with PsA without axial arthritis (pPsA), 117 with PsA with axial arthritis (psoriatic spondyloarthritis, PsSpA), 157 with ankylosing spondylitis (AS) without psoriasis, and 50 matched healthy controls (HC). Serum biomarker concentrations were measured using ELISA. Multivariable regression and receiver operating characteristic analyses were performed.

Results

MMP-3 concentrations were significantly higher and M-CSF significantly lower in each arthritis disease group compared with HC (p ≤ 0.02). MMP-3 concentrations were significantly higher (adjusted odds ratio, OR_adj 1.02 per ng/ml increase in concentration; p = 0.0004) and M-CSF significantly lower (OR_adj 0.44 per ng/ml increase; p = 0.01) in PsA (pPsA and PsSpA combined) compared with PsC. Dkk-1 concentrations were significantly higher (OR_adj 1.22 per ng/mL increase; p = 0.01), and OPG concentrations significantly lower (OR_adj 0.20 per ng/mL increase; p = 0.02) in patients with axial arthritis (PsSpA and AS combined) than in those without (pPsA). Furthermore, Dkk-1 concentrations were significantly higher along a spectrum of increasing axial arthritis; Dkk-1 concentrations were higher in AS compared with PsSpA (OR_adj 1.18 per ng/mL increase; p = 0.02). Receiver operating characteristic analysis showed MMP-3 to be the best single biomarker for differentiating PsA from PsC (AUC 0.70 for a cut-off of 14.51 ng/mL; sensitivity 0.76, specificity 0.60).

Conclusions

MMP-3 and M-CSF are biomarkers for the presence of arthritis in psoriatic disease, and could therefore be used to screen for PsA in psoriasis cohorts. Dkk-1 and OPG are biomarkers of axial arthritis; they could therefore be used to screen for the presence of axial disease in PsA cases, and help differentiate PsSpA from AS. High concentrations of Dkk-1 in AS and PsSpA compared with HC, support previous reports that Dkk-1 is dysfunctional in the spondyloarthritides.

Serum inflammatory biomarkers fail to identify early axial spondyloarthritis: results from the SpondyloArthritis Caught Early (SPACE) cohort

Introduction

Decreasing the diagnostic delay in axial spondyloarthritis (axSpA) remains a major challenge. Here, we assessed the value of serum inflammatory biomarkers to distinguish early axSpA from other pathologies in a large cohort of patients referred with early back pain.

Methods

Serum c reactive protein (CRP), erythrocyte sedimentation rate (ESR) and calprotectin were determined in the SPondyloArthritis Caught Early (SPACE) cohort (n=310), an early back pain inception cohort. Additionally, explorative serum biomarkers derived from the literature (interleukin-27 (IL-27), human β-defensin-2 (hBD-2) and lipcolin-2 (LCN-2)) were determined by ELISA in full-blown patients with ankylosing spondylitis (AS) (n=21) and healthy controls (n=20).

Results

Serum CRP and ESR levels were not elevated in early axSpA versus ‘control’ back pain patients. Serum calprotectin was elevated in early axSpA versus controls (p=0.01) but failed to identify early axSpA at the individual level (positive predictive value of 38.7%). As to explorative biomarkers, serum levels of IL-27 were not detectable, and hBD-2 and LCN-2 serum levels were not elevated in full-blown AS versus healthy controls (p=0.572, p=0.562, respectively). Therefore, these markers were not further determined in the SPACE cohort.

Conclusions

None of the candidate serum inflammatory markers were useful as diagnostic markers in the early phase of axSpA.

A proof-of-concept study with the tyrosine kinase inhibitor nilotinib in spondyloarthritis

Background

To evaluate the immunomodulating and clinical effects of nilotinib, a tyrosine kinase inhibitor, in a proof-of-concept study in spondyloarthritis (SpA) assessing the mast cell as potential novel therapeutic target in this disease.

Methods

Twenty eight patients with active peripheral (pSpA) and/or axial SpA (axSpA) were included in a randomized, double-blind, placebo-controlled clinical trial (Trial registration: Trialregister.nl NTR2834). Patients were treated 1:1 with nilotinib or placebo for 12 weeks, followed by an open label extension for another 12 weeks. Paired synovial tissue biopsies, serum sampling and assessment of clinical symptoms were performed serially.

Results

In pSpA (n = 13) synovial inflammation appeared to diminish after 12 weeks of nilotinib treatment as evidenced by histopathology (decrease in number of infiltrating CD68+ and CD163+ macrophages and mast cells). Compared to placebo mRNA expression of c-Kit as mast cell marker (p = 0.037) and of pro-inflammatory cytokines such as IL-6 (p = 0.024) were reduced. The reduction of synovial inflammation was paralleled by a decrease in serum biomarkers of inflammation such as C-reactive protein (p = 0.024) and calprotectin (p = 0.055). Also clinical parameters such as patient’s global assessment of disease activity (p = 0.031) and ankylosing spondylitis disease activity score (p = 0.031) showed improvement upon 12 weeks of nilotinib but not placebo treatment. This improvement was further augmented at week 24. In contrast to pSpA, neither serum biomarkers of inflammation nor clinical parameters improved upon nilotinib treatment in axSpA. During the trial one serious adverse event occurred, which was considered unrelated to the study drug.

Conclusions

This small proof-of-concept study suggests that nilotinib treatment modulates inflammation and clinical symptoms in pSpA. A similar effect was not seen in axSpA.

Trial registration: trialregister.nl registration code NTR2834 registered 31 March 2011

Hyperoside exerts anti-inflammatory and anti-arthritic effects in LPS-stimulated human fibroblast-like synoviocytes in vitro and in mice with collagen-induced arthritis

AIM

Hyperoside is a flavonol glycoside mainly found in plants of the genera Hypericum and Crataegus, which has shown anti-oxidant, anti-cancer and anti-inflammatory activities. In this study, we investigated the effects of hyperoside on human rheumatoid fibroblast-like synoviocytes (FLSs) in vitro and on mouse collagen-induced arthritis (CIA) in vivo.

METHODS

FLSs were isolated from primary synovial tissues obtained from rheumatoid arthritis (RA) patients and exposed to LPS (1 μg/mL). Cell viability and proliferation were measured with MTT and BrdU assay. Cell migration was assessed using wound-healing assay and Transwell assay. DNA binding of NF-κB was measured using a TransAM-NFkappaB kit. The localization of p65 subunit was detected with immunocytochemistry. CIA was induced in mice by primary immunization with Bovine Type II collagen (CII) emulsified in CFA, followed by a booster injection 3 weeks later. The arthritic mice were treated with hyperoside (25, 50 mg·kg(-1)·d(-1), ip) for 3 weeks, and the joint tissues were harvested for histological analysis.

RESULTS

Hyperoside (10, 50, 100 μmol/L) dose-dependently inhibited LPS-induced proliferation and migration of human RA FLSs in vitro. Furthermore, hyperoside decreased LPS-stimulated production of TNF-α, IL-6, IL-1 and MMP-9 in the cells. Moreover, hyperoside inhibited LPS-induced phosphorylation of p65 and IκBα, and suppressed LPS-induced nuclear translocation of p65 and DNA biding of NF-κB in the cells. Three-week administration of hyperoside significantly decreased the clinical scores, and alleviated synovial hyperplasia, inflammatory cell infiltration and cartilage damage in mice with CIA.

CONCLUSION

Hyperoside inhibits LPS-induced proliferation, migration and inflammatory responses in human RA FLSs in vitro by suppressing activation of the NF-κB signaling pathway, which contributes to the therapeutic effects observed in mice with CIA.

Brucella abortus-infected B cells induce osteoclastogenesis

Brucella abortus is an intracellular bacterium that establishes lifelong infections in livestock and humans although the mechanisms of its chronicity are poorly understood. Activated B cells have long lifespan and B. abortus infection activates B cells. Our results indicate that the direct infection of B cells with B. abortus induced matrix metalloproteinase-9 (MMP-9), receptor activator for NF κB ligand (RANKL), tumor necrosis factor (TNF)-α and interleukin (IL)-6 secretion. In addition, supernatants from B. abortus-infected B cells induced bone marrow-derived monocytes to undergo osteoclastogenesis. Using osteoprotegerin, RANKL's decoy receptor, we determined that RANKL is involved in osteoclastogenesis induced by supernatants from B. abortus-infected B cells. The results presented here shed light on how the interactions of B. abortus with B cells may have a role in the pathogenesis of brucellar osteoarticular disease.

Cartilage collagen type II seromarker patterns in axial spondyloarthritis and psoriatic arthritis: associations with disease activity, smoking and HLA-B27

The aim of the study was to assess the possible association between type II collagen turnover seromarkers and disease profile in patients with axial spondyloarthritis (SpA) and psoriatic arthritis (PsA). Outpatients with axial SpA (n = 110) or PsA (n = 101) underwent clinical examination including disease activity measures and HLA-B27 typing. The procollagen IIA N-terminal peptide (PIIANP) and a matrix metalloproteinase-generated type II collagen fragment (C2M) were quantified in serum by ELISA. C2M was higher in SpA than in controls, 0.41 versus 0.36 ng/ml (p = 0.004), while PIIANP did not differ between patients and healthy subjects, 2252 versus 2142 ng/ml (p = 0.13). However, DMARD-naïve SpA patients had higher PIIANP, 2461 ng/ml (p = 0.01) and C2M, 0.44 ng/ml (p = 0.0007) levels than controls, and PIIANP correlated with CRP (ρ = 0.34). C2M was lower in SpA smokers, 0.36 ng/ml versus non-smokers, 0.43 ng/ml (p = 0.02), while PIIANP was higher in HLA-B27 positive, 2312 ng/ml versus negative patients, 2021 ng/ml (p = 0.03). In PsA, PIIANP and C2M did not differ between patients and controls, but PIIANP was elevated in patients not receiving DMARDs, 2726 ng/ml. In PsA, PIIANP and C2M did not differ according to smoking and HLA-B27. Cartilage degradation assessed by C2M is increased in SpA irrespective of treatment but not in PsA. Cartilage synthesis reflected by PIIANP is increased in untreated SpA and PsA. PIIANP correlates with CRP in SpA while not in PsA. In DMARD-naïve SpA but not in PsA, HLA-B27 positivity and smoking are associated with a chondro-proliferative metabolic pattern.

Proteolytic cleavage and loss of function of biologic agents that neutralize tumor necrosis factor in the mucosa of patients with inflammatory bowel disease

BACKGROUND & AIMS

Many patients with inflammatory bowel disease (IBD) fail to respond to anti-tumor necrosis factor (TNF) agents such as infliximab and adalimumab, and etanercept is not effective for treatment of Crohn's disease. Activated matrix metalloproteinase 3 (MMP3) and MMP12, which are increased in inflamed mucosa of patients with IBD, have a wide range of substrates, including IgG1. TNF-neutralizing agents act in inflamed tissues; we investigated the effects of MMP3, MMP12, and mucosal proteins from IBD patients on these drugs.

METHODS

Biopsy specimens from inflamed colon of 8 patients with Crohn's disease and 8 patients with ulcerative colitis, and from normal colon of 8 healthy individuals (controls), were analyzed histologically, or homogenized and proteins were extracted. We also analyzed sera from 29 patients with active Crohn's disease and 33 patients with active ulcerative colitis who were candidates to receive infliximab treatment. Infliximab, adalimumab, and etanercept were incubated with mucosal homogenates from patients with IBD or activated recombinant human MMP3 or MMP12 and analyzed on immunoblots or in luciferase reporter assays designed to measure TNF activity. IgG cleaved by MMP3 or MMP12 and antihinge autoantibodies against neo-epitopes on cleaved IgG were measured in sera from IBD patients who subsequently responded (clinical remission and complete mucosal healing) or did not respond to infliximab.

RESULTS

MMP3 and MMP12 cleaved infliximab, adalimumab, and etanercept, releasing a 32-kilodalton Fc monomer. After MMP degradation, infliximab and adalimumab functioned as F(ab')2 fragments, whereas cleaved etanercept lost its ability to neutralize TNF. Proteins from the mucosa of patients with IBD reduced the integrity and function of infliximab, adalimumab, and etanercept. TNF-neutralizing function was restored after incubation of the drugs with MMP inhibitors. Serum levels of endogenous IgG cleaved by MMP3 and MMP12, and antihinge autoantibodies against neo-epitopes of cleaved IgG, were higher in patients who did not respond to treatment vs responders.

CONCLUSIONS

Proteolytic degradation may contribute to the nonresponsiveness of patients with IBD to anti-TNF agents.

Brucella abortus Invasion of Osteocytes Modulates Connexin 43 and Integrin Expression and Induces Osteoclastogenesis via Receptor Activator of NF-κB Ligand and Tumor Necrosis Factor Alpha Secretion

Osteoarticular brucellosis is the most common localization of human active disease. Osteocytes are the most abundant cells of bone. They secrete factors that regulate the differentiation of both osteoblasts and osteoclasts during bone remodeling. The aim of this study is to determine if Brucella abortus infection modifies osteocyte function. Our results indicate that B. abortus infection induced matrix metalloproteinase 2 (MMP-2), receptor activator for NF-κB ligand (RANKL), proinflammatory cytokines, and keratinocyte chemoattractant (KC) secretion by osteocytes. In addition, supernatants from B. abortus-infected osteocytes induced bone marrow-derived monocytes (BMM) to undergo osteoclastogenesis. Using neutralizing antibodies against tumor necrosis factor alpha (TNF-α) or osteoprotegerin (OPG), RANKL's decoy receptor, we determined that TNF-α and RANKL are involved in osteoclastogenesis induced by supernatants from B. abortus-infected osteocytes. Connexin 43 (Cx43) and the integrins E11/gp38, integrin-α, integrin-β, and CD44 are involved in cell-cell interactions necessary for osteocyte survival. B. abortus infection inhibited the expression of Cx43 but did not modify the expression of integrins. Yet the expression of both Cx43 and integrins was inhibited by supernatants from B. abortus-infected macrophages. B. abortus infection was not capable of inducing osteocyte apoptosis. However, supernatants from B. abortus-infected macrophages induced osteocyte apoptosis in a dose-dependent manner. Taken together, our results indicate that B. abortus infection could alter osteocyte function, contributing to bone damage.

Changes of serum levels of MMP-3, sRANKL, and OPG in juvenile-onset ankylosing spondylitis patients carrying different HLA-B27 subtypes

Ankylosing spondylitis (AS) patients whose symptom onset occurs before 16 years of age are termed juvenile-onset ankylosing spondylitis (JAS). Investigations suggested that JAS had worse functional outcome, and abnormality of bone metabolism can appear in early stage of AS. The objectives of this study are to compare changes of serum inflammatory and bone metabolic markers and to explore the relationship between these biomarkers and disease activity in JAS with different HLA-B27 subtypes. Serum matrix metallopeptidase-3 (MMP-3), soluble receptor activator of nuclear factor-κB ligand (sRANKL), and osteoprotegerin (OPG) were detected by ELISA in 56, 62, and 68 JAS patients, respectively, and 32 healthy individuals were as controls. Serum MMP-3 and sRANKL were significantly higher and OPG in JAS was slightly higher than those in controls. There was no significant difference in the level of MMP-3, sRANKL, and OPG among JAS patients with B27 negativity, B*2704, B*2705, and B*2715, respectively. Serum levels of MMP-3 showed positive correlation with BASDAI and BASFI (Bath Ankylosing Spondylitis Disease Activity Index and Functional Index). Serum level of sRANKL showed positive correlation with MMP-3 and negative correlation with disease duration. The significantly higher sRANKL expression suggested the enhanced osteoclast function and imbalance of RANKL/OPG system in the inflammatory process of JAS patients carrying different B27 subtypes. It should be paid attention to the abnormality of bone metabolism during the treatment of JAS.

Ultrasonographic evaluation of femoral cartilage thickness in patients with ankylosing spondylitis

OBJECTIVE

To evaluate femoral cartilage thickness in patients with ankylosing spondylitis (AS) by using ultrasonography.

METHODS

Eighty-four patients (55 M, 29 F) with a diagnosis of AS and 84 age-, gender- and body mass index-matched healthy subjects were enrolled. Demographic and clinical characteristics of the patients including disease duration, morning stiffness and medications were recorded. The femoral cartilage thicknesses of both knees were measured with a 7-12 MHz linear probe while subjects' knees were held in maximum flexion. Three mid-point measurements were taken from both knees (lateral femoral condyle (LFC), intercondylar area (ICA) and medial femoral condyle (MFC)).

RESULTS

Concerning both ICA (p < 0.001) and left MFC (p = 0.013), cartilage measurements were significantly thicker in AS patients than control subjects. In a subgroup analysis (anti-tumour necrosis factor (TNF) users vs anti-TNF naive), cartilage thickness measurements - bilateral ICA (p = 0.000) and left MFC (p = 0.017) - were found to be greater in AS patients under anti-TNF treatment (n = 65) when compared with those of healthy controls.

CONCLUSION

We imply that AS patients seem to have thicker femoral cartilage, which could be related to anti-TNF treatment.

Calprotectin (S100A8/9) as serum biomarker for clinical response in proof-of-concept trials in axial and peripheral spondyloarthritis

Introduction

Biomarkers complementing clinical evaluations may help to reduce the length and size of proof-of-concept (PoC) trials aimed to obtain quick “go/no go” decisions in the clinical development of new treatments. We aimed to identify and validate serum biomarkers with a high sensitivity to change upon effective treatment in spondyloarthritis (SpA) PoC trials.

Methods

The candidate biomarkers high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), pentraxin-3 (PTX-3), alpha-2-macroglobulin (alpha-2-MG), matrix metalloproteinase-3 (MMP-3), calprotectin, and vascular endothelial growth factor (VEGF) were determined by enzyme-linked immunosorbent assay (ELISA) in healthy controls (n = 20) and SpA patients before and after 2 weeks of infliximab (n = 18) or placebo (n = 19) treatment in cohort 1. Clinical outcome was evaluated at week 12. Results were validated in ankylosing spondylitis (AS) with infliximab (cohort 2, n = 21) and peripheral SpA with etanercept (cohort 3, n = 20).

Results

Serum levels of calprotectin, hs-CRP, PTX-3, VEGF (all P < 0.001) and MMP-3 (P = 0.062), but not IL-6 and alpha-2-MG, were increased in SpA versus healthy controls. Treatment with infliximab, but not placebo, significantly decreased calprotectin (P < 0.001) and hs-CRP (P < 0.001) levels, with a similar trend for MMP-3 (P = 0.063). The standardized response mean (SRM), which reflects the ability to detect changes over time, was high for calprotectin (−1.26), good for hs-CRP (−0.96) and moderate for MMP-3 (−0.52). Calprotectin and hs-CRP, but not MMP-3, were good biomarkers for treatment response in axial and peripheral SpA as evaluated and confirmed in cohort 2 and 3 respectively.

Conclusions

Calprotectin and hs-CRP are good serum biomarkers with high sensitivity to change upon effective treatment at the group level in small-scale, short term PoC trials in SpA.

Expression profiling in spondyloarthropathy synovial biopsies highlights changes in expression of inflammatory genes in conjunction with tissue remodelling genes

BACKGROUND

In the spondyloarthropathies, the underlying molecular and cellular pathways driving disease are poorly understood. By undertaking a study in knee synovial biopsies from spondyloarthropathy (SpA) and ankylosing spondylitis (AS) patients we aimed to elucidate dysregulated genes and pathways.

METHODS

RNA was extracted from six SpA, two AS, three osteoarthritis (OA) and four normal control knee synovial biopsies. Whole genome expression profiling was undertaken using the Illumina DASL system, which assays 24000 cDNA probes. Differentially expressed candidate genes were then validated using quantitative PCR and immunohistochemistry.

RESULTS

Four hundred and sixteen differentially expressed genes were identified that clearly delineated between AS/SpA and control groups. Pathway analysis showed altered gene-expression in oxidoreductase activity, B-cell associated, matrix catabolic, and metabolic pathways. Altered "myogene" profiling was also identified. The inflammatory mediator, MMP3, was strongly upregulated (5-fold) in AS/SpA samples and the Wnt pathway inhibitors DKK3 (2.7-fold) and Kremen1 (1.5-fold) were downregulated.

CONCLUSIONS

Altered expression profiling in SpA and AS samples demonstrates that disease pathogenesis is associated with both systemic inflammation as well as local tissue alterations that may underlie tissue damaging modelling and remodelling outcomes. This supports the hypothesis that initial systemic inflammation in spondyloarthropathies transfers to and persists in the local joint environment, and might subsequently mediate changes in genes directly involved in the destructive tissue remodelling.

Rheumatoid factor positivity is associated with increased joint destruction and upregulation of matrix metalloproteinase 9 and cathepsin k gene expression in the peripheral blood in rheumatoid arthritic patients treated with methotrexate

We evaluated changes in gene expression of mTOR, p21, caspase-3, ULK1, TNFα, matrix metalloproteinase (MMP)-9, and cathepsin K in the whole blood of rheumatoid arthritic (RA) patients treated with methotrexate (MTX) in relation to their rheumatoid factor status, clinical, immunological, and radiological parameters, and therapeutic response after a 24-month follow-up. The study group consisted of 35 control subjects and 33 RA patients without previous history of MTX treatment. Gene expression was measured using real-time RT-PCR. Decreased disease activity in patients at the end of the study was associated with significant downregulation of TNFα expression. Downregulation of mTOR was observed in seronegative patients, while no significant changes in the expression of p21, ULK1, or caspase-3 were noted in any RA patients at the end of the study. The increase in erosion numbers observed in the seropositive patients at the end of the follow-up was accompanied by upregulation of MMP-9 and cathepsin K, while seronegative patients demonstrated an absence of significant changes in MMP-9 and cathepsin K expression and no increase in the erosion score. Our results suggest that increased expression of MMP-9 and cathepsin K genes in the peripheral blood might indicate higher bone tissue destruction activity in RA patients treated with methotrexate. The clinical study registration number is 0120.0810610.

Circulating Levels of Soluble Receptor Activator of NF- κ B Ligand and Matrix Metalloproteinase 3 (and Their Antagonists) in Asian Indian Patients with Ankylosing Spondylitis

Background. Bone loss in ankylosing spondylitis may be related to inflammation. Data from previous studies on circulating levels of sRANKL, OPG, MMP3, and TIMP is inconsistent; thus this study is planned to look at this aspect in Asian Indian patients. Methods. Cross-sectional study included patients with ankylosing spondylitis and age- and gender-similar controls. Serum levels of sRANKL, OPG, MMP-3, and TIMP-1 were measured by ELISA. Results. Included 85 patients (M : F = 82 : 3) having mean age (±SD) 33.0 ± 10.0 years and disease duration 11.3 ± 7.3 years. BASDAI, BASFI, BASMI, and ESR were 4.0 ± 2.2, 3.9 ± 2.8, 3.0 ± 2.8, and 59.2 ± 31.2, respectively. Patients had higher mean (±SD) OPG level (649.7 ± 286.8, 389.3 ± 244.8 pg/mL, P < 0.001). However, there was no difference in sRANKL (349.2 ± 872.0, 554.7 ± 1850.1, P = ns). Serum MMP-3 (91.4 ± 84.7, 55.9 ± 37.1 ng/mL, P < 0.01) and TIMP-1 (520.6 ± 450.7, 296.5 ± 114.2 ng/mL, P < 0.001) levels were higher in patients; however, there was no difference in MMP-3/TIMP-1 ratio. Conclusion. Circulating levels of OPG were higher; however, there was no difference in sRANKL in Asian Indian ankylosing spondylitis patients. Although both MMP-3 and TIMP-1 were raised, their ratio was not different from that of controls.

Association of biomarkers of inflammation, cartilage and bone turnover with gender, disease activity, radiological damage and sacroiliitis by magnetic resonance imaging in patients with early spondyloarthritis

To assess the association between biomarkers of inflammation, cartilage and bone turnover with gender, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Spondylitis Disease Activity Score (ASDAS) and bone marrow oedema in resonance magnetic imaging (MRI) of sacroiliac joints (SIJs) and radiological damage in early spondyloarthritis (SpA). Cross-sectional study of 60 patients (56.7 % females; mean age, 32.4 years) with early SpA. Sociodemographic data, clinical features, serum matrix metalloproteinase 3 (MMP-3), high sensitivity C-reactive protein (hsCRP), C-terminal cross-linking telopeptides of type I collagen (CTX-I) and urinary deoxypyridinoline, ASDAS, BASDAI, BASFI, BASRI and MRI of the SIJs were collected. The mean (SD) disease duration was 12.4 (6.8 months). Twenty-two (68.7 %) of the 32 patients had active sacroiliitis by MRI. MMP-3 and CTX I correlated with swollen joint (r = 0.515, r = 0.386, p = 0.01). hsCRP correlated with ESR (r = 0.303, p = 0.05), with CRP (r = 0.455, p = 0.01) and with total BASRI (r = 0.95, p = 0.05). Biomarkers were unrelated with the rest of variables. Levels of MMP-3 (44.3 ± 52.4 vs 24.7 ± 33.4, p < 0.05) and CTX-I (0.53 ± 0.45 vs 0.24 ± 0.38; p < 0.05) were higher in men. Our study shows that CTX-I and MMP-3 are a marker of peripheral disease activity in early SpA. Male gender had higher levels of CTX-I and MMP-3, which may indicate higher disease activity. Higher hsCRP levels trended towards correlation with more baseline radiographic damage. Therefore, these biomarkers may help identify a subgroup of patients who will need closer monitoring and more intensive treatment.

Why is biologic therapy useful in spondyloarthritis? Knowledge from synovial immunopathologic studies of spondyloarthritis

The pathogenesis of most rheumatic diseases remains unknown. It is believed that both genetic and environmental factors play a pivotal role in the development of synovial inflammation in rheumatoid arthritis (RA), spondyloarthritis (SpA) and osteoarthritis (OA). In the last two decades, there have been many immunopathologic studies on RA, SpA and OA, and the findings revealed different types of arthritis may also present different pathologic patterns. These included higher vascularity and increased infiltration with CD163 macrophages and neutrophils, but relatively low values for lining cell (LL) hyperplasia in SpA synovium. However, the increased LL hyperplasia, as well as CD1a+ cells and the presence of intracellular citrullinated protein were more prominent in RA than in SpA synovitis. Anti-tumor necrosis factor alpha (anti-TNFα) therapy can significantly reduce synovial LL hyperplasia, vascularity and mononuclear cells infiltration in the majority of RA or SpA patients. This may explain why clinically, arthritis patients can get significant improvement after TNFα blocker treatment.

Association of cytokine and matrix metalloproteinase profiles with disease activity and function in ankylosing spondylitis

Introduction

The pathology of ankylosing spondylitis (AS) suggests that certain cytokines and matrix metalloproteinases (MMPs) might provide useful markers of disease activity. Serum levels of some cytokines and MMPs have been found to be elevated in active disease, but there is a general lack of information about biomarker profiles in AS and how these are related to disease activity and function. The purpose of this study was to investigate whether clinical measures of disease activity and function in AS are associated with particular profiles of circulating cytokines and MMPs.

Methods

Measurement of 30 cytokines, five MMPs and four tissue inhibitors of metalloproteinases was carried out using Luminex^® technology on a well-characterised population of AS patients (n = 157). The relationship between biomarker levels and measures of disease activity (Bath ankylosing spondylitis disease activity index (BASDAI)), function (Bath ankylosing spondylitis functional index) and global health (Bath ankylosing spondylitis global health) was investigated. Principal component analysis was used to reduce the large number of biomarkers to a smaller set of independent components, which were investigated for their association with clinical measures. Further analyses were carried out using hierarchical clustering, multiple regression or multivariate logistic regression.

Results

Principal component analysis identified eight clusters consisting of various combinations of cytokines and MMPs. The strongest association with the BASDAI was found with a component consisting of MMP-8, MMP-9, hepatocyte growth factor and CXCL8, and was independent of C-reactive protein levels. This component was also associated with current smoking. Hierarchical clustering revealed two distinct patient clusters that could be separated on the basis of MMP levels. The high MMP cluster was associated with increased C-reactive protein, the BASDAI and the Bath ankylosing spondylitis functional index.

Conclusions

A profile consisting of high levels of MMP-8, MMP-9, hepatocyte growth factor and CXCL8 is associated with increased disease activity in AS. High MMP levels are also associated with smoking and worse function in AS.

MMP mediated type V collagen degradation (C5M) is elevated in ankylosing spondylitis

OBJECTIVES

Type V collagen has been demonstrated to control fibril formation. The aim of this study was to develop an ELISA capable of detecting a fragment of type V collagen generated by MMP-2/9 and to evaluate the assay as biomarker for ankylosing spondylitis (AS).

DESIGN AND METHODS

A fragment unique to type V collagen and generated by both MMP-2/9 cleaved at the amino acid position 1317 (C5M) was selected for ELISA development. 40 AS patients and 40 age-matched controls were evaluated.

RESULTS

An ELISA detecting C5M with inter- and intra-assay variations of 9.1% and 4.4% was developed. C5M levels were significantly higher in AS patients compared to controls, 229% (p<0.0001). The diagnostic AUC was 83%.

CONCLUSIONS

This ELISA is the first for detecting type V collagen degradation. AS patients had highly elevated levels of MMP mediated type V collagen degradation. The prognostic and diagnostic values need to be further investigated in additional clinical settings.

Synovial Tissue Response to Treatment with TNF Blockers in Peripheral Spondyloarthritis

This review describes the synovial response to treatment in peripheral spondyloarthritis (SpA). A series of recent studies demonstrates that the synovial histopathology is largely homogenous between different SpA subtypes and can be strongly modulated by effective treatment such as tumor necrosis factor (TNF) blockade. This includes a dramatic reduction of the infiltration with inflammatory cells (with the intriguing exception of B lymphocytes and plasma cells), a modulation of structural features such as vascularity, intimal lining layer hyperplasia, and ectopic lymphoid neogenesis, and a down-regulation of a variety of mediators involved in tissue damage. The analysis of tissue response to targeted therapies appears to be a novel and elegant approach to study the immunopathology of human peripheral SpA in vivo. Moreover, detailed cellular and molecular analysis of synovial features allows to identify synovial biomarkers of clinical response to therapeutic interventions which can be used in future early phase clinical trials in SpA.

[Psoriatic arthritis : a permanent challenge for rheumatologists and patients--Part 1: epidemiology, pathogenesis and clinical course]

Psoriatic arthritis is still one of the big challenges in rheumatology due to the great variety of symptoms. Treatment frequently requires an interdisciplinary collaboration of general practitioners, dermatologists and rheumatologists who are able to recognize the onset of disease early by means of classification criteria and new imaging techniques followed by the implementation of appropriate antirheumatic treatment. During recent years new immunological pathways have been discovered leading to an increasing number of potential therapies, which increases the chance to find effective individualized treatment. However, tracking back the onset of the disease to specific causes is still a challenge which is made even more complex due to the absence of specific serum parameters.

Levels of serum matrix metalloproteinase-3 correlate with disease activity in the enthesitis-related arthritis category of juvenile idiopathic arthritis

OBJECTIVE

Serum matrix metalloproteinase-3 (MMP-3) has been shown to reflect disease activity in ankylosing spondylitis (AS) and rheumatoid arthritis. Elevated levels have been found in juvenile idiopathic arthritis (JIA). In the enthesitis-related arthritis category of JIA (JIA-ERA), we studied whether serum MMP-3 levels and ratios of MMP-3/tissue inhibitor of metalloproteinase (TIMP-1) are correlated with disease activity and whether they are sensitive to change in disease activity.

METHODS

A total of 54 patients with JIA-ERA (International League of Associations for Rheumatology criteria) were enrolled for study. Baseline disease activity measures included tender and swollen joint counts, Maastricht AS Enthesitis Score, Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), patient assessment of pain and global disease activity, physician assessment of global disease activity, and erythrocyte sedimentation rate (ESR). Serum MMP-3 and TIMP-1 levels were measured using ELISA. A group of 24 patients were followed up for longitudinal study.

RESULTS

The mean age of 54 patients (48 males) at disease onset was 11.8 ± 4.19 years and duration of disease was 5.2 ± 4.3 years. Median ESR was 65 mm/h (range 46.5-97) and median BASDAI was 3.4 (range 2.5-4.7). Median MMP-3, TIMP-1, and MMP-3/TIMP-1 ratio were 50.4 ng/ml (IQR 13.0-193.8), 228.9 ng/ml (IQR 108.2-290.4), and 0.3 (IQR 0.07-1.13), respectively. At inclusion MMP-3 levels correlated directly with various disease activity measures: tender joint count (TJC; r = 0.60), swollen joint count (SJC; r = 0.45), BASFI (r = 0.29), BASDAI (r = 0.32), ESR (r = 0.49), physician global assessment (r = 0.40), patient visual analog scale for pain (r = 0.28), and patient global assessment (r = 0.38; all p < 0.05). MMP-3/TIMP-1 ratio correlated only with TJC (r = 0.51), SJC (r = 0.39), and ESR (r = 0.34; p < 0.05). At followup, change in MMP-3 correlated with changes in TJC (r = 0.42) and SJC (r = 0.44; p < 0.05), while change in ESR did not correlate with change in any disease activity measure.

CONCLUSION

MMP-3 levels are a good marker for disease activity in JIA-ERA.

Spondyloarthritis

Spondyloarthritis is a group of several related but phenotypically distinct disorders: psoriatic arthritis, arthritis related to inflammatory bowel disease, reactive arthritis, a subgroup of juvenile idiopathic arthritis, and ankylosing spondylitis (the prototypic and best studied subtype). The past decade yielded major advances in the recognition of spondyloarthritis as an entity, the classification of the disease, and understanding of the genetic and pathophysiological mechanisms of disease-related inflammation and tissue damage. In parallel, new clinical and imaging outcomes have allowed the assessment of various therapeutic modalities. Blockers of tumour necrosis factor are a major therapeutic advance, but the exact roles of physiotherapy, and treatment with non-steroidal anti-inflammatory drugs and other biological treatments are unknown. The major challenges with direct relevance for clinical practice for the next decade are the development of techniques for early diagnosis, therapeutic modulation of structural damage, and, ultimately, induction of long-term, drug-free remission.

Serum MMP-3 Level as a Biomarker for Monitoring and Predicting Response to Etanercept Treatment in Ankylosing Spondylitis

Objective.

To investigate whether level of serum matrix metalloproteinase-3 (MMP-3) can serve as a biomarker for monitoring and predicting response to etanercept treatment in patients with ankylosing spondylitis (AS) in daily clinical practice.

Methods.

Ninety-two consecutive AS outpatients with active disease who started etanercept treatment were included in this longitudinal observational study. Clinical data were collected prospectively at baseline and after 3 and 12 months of treatment. At the same timepoints, serum MMP-3 levels were measured retrospectively by ELISA.

Results.

Since baseline serum MMP-3 levels were significantly higher in male compared to female patients with AS, data analysis was split for gender. Changes in serum MMP-3 levels after etanercept treatment correlated positively with changes in clinical assessments of disease activity and physical function in both male and female patients. Receiver operating characteristic analysis in male patients showed that baseline serum MMP-3 levels had poor accuracy (AUC < 0.7) to discriminate between Assessments in Ankylosing Spondylitis 20 (ASAS20) or ASAS40 responders and nonresponders after 3 or 12 months of treatment. The accuracy of change in serum MMP-3 levels from baseline to 3 months in predicting response after 3 or 12 months of treatment was poor for ASAS40 (AUC < 0.7) or moderate for ASAS20 (AUC = 0.752 and 0.744, respectively), and was not superior to the accuracy of change in the currently used objective biomarkers, erythrocyte sedimentation rate and C-reactive protein.

Conclusion.

Although significant changes in serum MMP-3 levels were found after etanercept treatment, data analysis indicates that serum MMP-3 levels are not very useful for monitoring and predicting response to etanercept treatment in patients with AS in daily clinical practice.

Biochemical markers of ongoing joint damage in rheumatoid arthritis--current and future applications, limitations and opportunities

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease associated with potentially debilitating joint inflammation, as well as altered skeletal bone metabolism and co-morbid conditions. Early diagnosis and aggressive treatment to control disease activity offers the highest likelihood of preserving function and preventing disability. Joint inflammation is characterized by synovitis, osteitis, and/or peri-articular osteopenia, often accompanied by development of subchondral bone erosions, as well as progressive joint space narrowing. Biochemical markers of joint cartilage and bone degradation may enable timely detection and assessment of ongoing joint damage, and their use in facilitating treatment strategies is under investigation. Early detection of joint damage may be assisted by the characterization of biochemical markers that identify patients whose joint damage is progressing rapidly and who are thus most in need of aggressive treatment, and that, alone or in combination, identify those individuals who are likely to respond best to a potential treatment, both in terms of limiting joint damage and relieving symptoms. The aims of this review are to describe currently available biochemical markers of joint metabolism in relation to the pathobiology of joint damage and systemic bone loss in RA; to assess the limitations of, and need for additional, novel biochemical markers in RA and other rheumatic diseases, and the strategies used for assay development; and to examine the feasibility of advancement of personalized health care using biochemical markers to select therapeutic agents to which a patient is most likely to respond.

Are current available therapies disease-modifying in spondyloarthritis?

Disease modification in spondyloarthritis should target the improvement of symptoms and preservation of function. Therefore, inhibition of structural damage caused by the disease processes appears essential. In spondyloarthritis, structural damage results mainly in progressive ankylosis of the spine and peripheral joint destruction. Currently available therapies for the treatment of spondyloarthritis appear effective at inhibiting tissue destruction but, with the exception of celecoxib, do not appear to affect new tissue formation leading to ankylosis. In this article, we discuss clinical and pathophysiological concepts of disease modification in spondyloarthritis, challenges in its evaluation, recent clinical data and new concepts that may help explain structural damage as well as the onset and progression of disease.