Radiographic progression is associated with resolution of systemic inflammation in patients with axial spondylarthritis treated with tumor necrosis factor α inhibitors: A study of radiographic progression, inflammation on magnetic resonance imaging, and c

Serum biomarkers and their relationship to axial spondyloarthritis associated with inflammatory bowel diseases

Spondyloarthritis (SpA) constitute a group of chronic inflammatory immune-mediated rheumatic diseases characterized by genetic, clinical, and radiological features. Recent efforts have concentrated on identifying biomarkers linked to axial SpA associated with inflammatory bowel disease (IBD), offering predictive insights into disease onset, activity, and progression. Genetically, the significance of the HLA-B27 antigen is notably diminished in ankylosing spondylitis (AS) associated with IBD, but is heightened in concurrent sacroiliitis. Similarly, certain polymorphisms of endoplasmic reticulum aminopeptidase (ERAP-1) appear to be involved. Carriage of variant NOD2/CARD15 polymorphisms has been demonstrated to correlate with the risk of subclinical intestinal inflammation in AS. Biomarkers indicative of pro-inflammatory activity, including C-reactive protein (CRP) along with erythrocyte sedimentation rate (ESR), are among the consistent predictive biomarkers of disease progression. Nevertheless, these markers are not without limitations and exhibit relatively low sensitivity. Other promising markers encompass IL-6, serum calprotectin (s-CLP), serum amyloid (SAA), as well as biomarkers regulating bone formation such as metalloproteinase-3 (MMP-3) and Dickkopf-related protein 1 (DKK-1). Additional candidate indicators of structural changes in SpA patients include matrix metalloproteinase-3 (MMP-3), vascular endothelial growth factor (VEGF), tenascin C (TNC), and CD74 IgG. Fecal caprotein (f-CLP) levels over long-term follow-up of AS patients have demonstrated predictive value in anticipating the development of IBD. Serologic antibodies characteristic of IBD (ASCA, ANCA) have also been compared; however, results exhibit variability. In this review, we will focus on biomarkers associated with both axial SpA and idiopathic intestinal inflammation, notably enteropathic spondyloarthritis.

Spinal Radiographic Progression and Predictors of Progression in Patients With Radiographic Axial Spondyloarthritis Receiving Ixekizumab Over 2 Years

OBJECTIVE

To evaluate the long-term effect of ixekizumab (IXE) on radiographic changes in the spine in patients with radiographic axial spondyloarthritis (r-axSpA) by measuring change from baseline through 2 years in modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS), and to identify potential predictors of progression.

METHODS

This study evaluates patients from COAST-V (ClinicalTrials.gov: NCT02696785, biologic disease-modifying antirheumatic drug-naïve) and COAST-W (NCT02696798, tumor necrosis factor inhibitor-experienced) who had mSASSS data at baseline in the originating studies and 108 weeks after baseline in the extension study COAST-Y (NCT03129100). We examined the proportion of patients who did not have spinal radiographic progression through 2 years (108 weeks) of treatment with IXE (80 mg every 2 or 4 weeks) and the change from baseline to year 2 in mSASSS. Potential predictors of spinal radiographic progression were also evaluated.

RESULTS

Among patients with evaluable radiographs who were originally assigned to IXE (n = 230), mean (SD) change in mSASSS from baseline at year 2 was 0.3 (1.8). The proportion of nonprogressors over 2 years was 89.6% if defined as mSASSS change from baseline < 2 and 75.7% if defined as mSASSS change from baseline ≤ 0. Predictors of structural progression at year 2 (mSASSS change > 0) were age ≥ 40, baseline syndesmophytes, HLA-B27 positivity, and male sex. Week 52 inflammation in Spondyloarthritis Research Consortium of Canada spine was also a predictor of radiographic progression at year 2 in patients with magnetic resonance imaging data in COAST-V (n = 109).

CONCLUSION

The majority of patients with r-axSpA receiving IXE had no radiographic progression in the spine through 2 years of treatment. Predictors were generally consistent with previous studies.

The value of SPARCC sacroiliac MRI scoring in axial psoriatic arthritis and its association with other disease parameters

OBJECTIVES

This study aimed to assess patients with axial psoriatic arthritis (AxPsA) using the Canadian Spondyloarthritis Research Consortium (SPARCC) sacroiliac joint (SIJ) scores and to seek correlations between magnetic resonance imaging (MRI) scores and disease characteristics.

METHODS

Forty PsA patients (32 females, mean age 46.4 years) who had been documented to have active or structural lesions on SIJ MRI were retrospectively evaluated. Disease duration, medications, and disease activity, including Disease Activity in Psoriatic Arthritis (DAPSA), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), minimal disease activity (MDA), and Ankylosing Spondylitis Disease Activity Score (ASDAS) were recorded. On sacroiliac MRI scans, the SPARCC scores of sacroiliac joint inflammation (SIS) and sacroiliac joint structural damage (SSS) were evaluated.

RESULTS

The mean disease duration was 51.4 ± 70.4 months. MRI showed active inflammation in 30 patients (75%) and at least 1 structural lesion in 32 patients (92.5%). The most prevalent structural lesion was erosion (82.5%), followed by fat metaplasia (65%), backfill (12.5%), and ankylosis (2.5%). Only fat metaplasia scores were significantly higher in men than in women (P = .007). Of clinical and laboratory parameters, only C-reactive protein (CRP) was significantly higher in the presence of active inflammation (P = .01). The SIS score was significantly correlated with disease duration (r = -.35) and CRP levels (r = .42,). The SSS score was inversely correlated with BASDAI (r = -.37), ASDAS-CRP (r = -.39), and ASDAS - erythrocyte sedimentation rate (r = -.32). The overall SPARCC scores did not differ between patients in DAPSA remission and non-remission and between those in MDA and non-MDA.

CONCLUSION

Although radiologic involvement is generally not severe in AxPsA, MRI still provides additional information about inflammatory activity and structural lesions. CRP may be helpful in monitoring the radiologic disease activity in AxPsA.

Anti-Osteogenic Effect of Danshensu in Ankylosing Spondylitis: An in Vitro Study Based on Integrated Network Pharmacology

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by abnormal bone metabolism, with few effective treatments available. Danshensu [3-(3,4-dihydroxy-phenyl) lactic acid) is a bioactive compound from traditional Chinese medicine with a variety of pharmacologic effects. In the present study, we investigated the pharmacologic effect and molecular mechanism of Danshensu in AS. Potential targets of Danshensu were identified in four drugs-genes databases; and potential pharmacologic target genes in AS were identified in three diseases-genes databases. Differentially expressed genes related to AS were obtained from the Gene Expression Omnibus database. Overlapping targets of Danshensu and AS were determined and a disease–active ingredient–target interaction network was constructed with Cytoscape software. Enrichment analyses of the common targets were performed using Bioconductor. To test the validity of the constructed network, an in vitro model was established by treating osteoblasts from newborn rats with low concentrations of tumor necrosis factor (TNF)-α. Then, the in vitro model and AS fibroblasts were treated with Danshensu (1–10 μM). Osteogenesis was evaluated by alkaline phosphatase staining and activity assay, alizarin red staining, quantitative PCR, and western blotting. We identified 2944 AS-related genes and 406 Danshensu targets, including 47 that were common to both datasets. The main signaling pathways associated with the targets were the c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) pathways. A low concentration of TNF-α (0.01 ng/ml) promoted the differentiation of osteoblasts; this was inhibited by Danshensu, which had the same effect on AS fibroblasts but had the opposite effect on normal osteoblasts. Danshensu also decreased the phosphorylation of JNK and ERK in AS fibroblasts. There results provide evidence that Danshensu exerts an anti-osteogenic effect via suppression of JNK and ERK signaling, highlighting its therapeutic potential for the treatment of AS.

Cytokine "fine tuning" of enthesis tissue homeostasis as a pointer to spondyloarthritis pathogenesis with a focus on relevant TNF and IL-17 targeted therapies

A curious feature of axial disease in ankylosing spondylitis (AS) and related non-radiographic axial spondyloarthropathy (nrAxSpA) is that spinal inflammation may ultimately be associated with excessive entheseal tissue repair with new bone formation. Other SpA associated target tissues including the gut and the skin have well established paradigms on how local tissue immune responses and proven disease relevant cytokines including TNF and the IL-23/17 axis contribute to tissue repair. Normal skeletal homeostasis including the highly mechanically stressed entheseal sites is subject to tissue microdamage, micro-inflammation and ultimately repair. Like the skin and gut, healthy enthesis has resident immune cells including ILCs, γδ T cells, conventional CD4+ and CD8+ T cells and myeloid lineage cells capable of cytokine induction involving prostaglandins, growth factors and cytokines including TNF and IL-17 that regulate these responses. We discuss how human genetic studies, animal models and translational human immunology around TNF and IL-17 suggest a largely redundant role for these pathways in physiological tissue repair and homeostasis. However, disease associated immune system overactivity of these cytokines with loss of tissue repair “fine tuning” is eventually associated with exuberant tissue repair responses in AS. Conversely, excessive biomechanical stress at spinal enthesis or peripheral enthesis with mechanically related or degenerative conditions is associated with a normal immune system attempts at cytokine fine tuning, but in this setting, it is commensurate to sustained abnormal biomechanical stressing. Unlike SpA, where restoration of aberrant and excessive cytokine “fine tuning” is efficacious, antagonism of these pathways in biomechanically related disease may be of limited or even no value.

Exploring IL-17 in spondyloarthritis for development of novel treatments and biomarkers

Spondyloarthritis (SpA) is an umbrella term describing a family of chronic inflammatory rheumatic diseases. These diseases are characterised by inflammation of the axial skeleton, peripheral joints, and entheseal insertion sites throughout the body which can lead to structural joint damage including formation of axial syndesmophytes and peripheral osteophytes. Genetic evidence, preclinical and clinical studies indicate a clear role of interleukin (IL)- 23 and IL-17 as mediators in SpA pathogenesis. Targeting the IL-23/-17 pathways seems an efficient strategy for treatment of SpA patients, and despite the remaining challenges the pathway holds great promise for further advances and improved therapeutic opportunities. Much research is focusing on serological markers and imaging strategies to correctly diagnose patients in the early stages of SpA. Biomarkers may facilitate personalised medicine tailored to each patient's specific disease to optimise treatment efficacy and to monitor therapeutic response. This narrative review focuses on the IL-17 pathway in SpA-related diseases with emphasis on its role in pathogenesis, current approved IL-17 inhibitors, and the need for biomarkers reflecting core disease pathways for early diagnosis and measurement of disease activity, prognosis, and response to therapy.

Diagnostic value of anti-CD74 antibodies in early and late axial spondyloarthritis and its relationship to disease activity

OBJECTIVES

This study was designed to evaluate the role of anti-CD74 antibodies in diagnosis of axial spondyloarthritis (axSpA) and their relationship to disease duration and disease activity.

METHODS

Fifty patients with axSpA, 15 patients with RA and 15 healthy subjects were included in the study. Clinical examination and laboratory tests were done. The ESR, CRP level and ASDAS were measured as markers of the disease activity. Quantitative determination of human CD74 IgG antibodies was done.

RESULTS

The mean age of the patients was 38.22 (S.D.12.20) years. The level of CD74 autoantibodies was significantly higher in axSpA in comparison to control groups. Most patients with positive articular and extra-articular manifestations were positive for CD74 autoantibodies. In patients with inactive disease, 33.3% were positive for CD74 autoantibodies, as were 83% with active disease. High percentages of patients with early and late axSPA were CD74 autoantibody positive. The majority of patients with positive disease activity in early and late axSpA were CD74 autoantibody positive. CD74 autoantibodies had 80% sensitivity vs both control groups with 87% specificity vs the healthy control group and 80% vs the RA control group in the diagnosis of axSpA.

CONCLUSIONS

The frequency of positive anti-CD74 IgG antibodies was as high in patients with early axSpA as in those with late axSpA, with no significant differences. There was a significant difference in the frequency of positive anti-CD74 IgG antibodies between patients with positive and negative disease activity. Based on the sensitivity and specificity of anti-CD74 IgG, this is a promising diagnostic tool to support the clinical diagnosis of axSpA.

Serum Biomarkers of Inflammation and Turnover of Joint Cartilage Can Help Differentiate Psoriatic Arthritis (PsA) Patients from Osteoarthritis (OA) Patients

The aim of this study was to find characteristic biomarkers in the serum of patients with osteoarthritis (OA) and psoriatic arthritis (PsA) responsible for inflammation and destruction of joint cartilage, which could differentiate these two diseases. The study included 67 people: 22 patients with knee OA, 22 patients with PsA, and 23 individuals who were the control group of healthy individuals (HC). The concentration of IL-18, IL-20, IL-6, MMP-1, MMP-3, COMP, PG-AG, and YKL-40 in serum were determined. Among the OA and PsA patients group, the radiological assessment and clinical assessment were also performed. The concentration of 7 out of 8 of examined biomarkers (except MMP-1) was statistically significantly higher in the serum of patients with OA and PsA than in the control group. Compering OA and PsA groups only, the serum PG-AG level in OA patients was statistically significantly higher than in PsA patients (p < 0.001). The results of univariate and multivariate logistic regression analysis comparing OA and PsA biomarker serum levels identified PG-AG and COMP as markers that are significantly different between patients with OA and PsA (odds ratio 0.995 and 1.003, respectively). The ROC curve constructed using the model with age showed PG-AG and COMP had an AUC of 0.907. The results of this study show that COMP and PG-AG may be sensitive markers differentiating patients with osteoarthiritis from psoriatic arthritis.

The role of biochemical markers of joint tissue remodelling to predict progression and treatment efficacy in inflammatory rheumatic diseases

Structural damage is a hallmark in RA, spondyloarthropy (SpA) and psoriatric arthritis (PsA). Its progression is difficult to predict and current radiological or inflammatory biological markers lack sensitivity. Biochemical markers of bone, cartilage and synovial tissues provide a dynamic indication of the anabolism and catabolism of joint tissues and can be easily measured by immunoassays. Novel biochemical markers including post-translational modifications of matrix proteins and enzyme-generated neoepitopes with increased tissue and/or biological pathway specificity have been developed. Their evaluation in clinical trials of novel biologic therapies and epidemiological studies indicated that their measurements could be useful to predict progression of structural damage and treatment efficacy, independently of current clinical, radiological and biological indices of disease activity. In this paper we briefly describe the latest developments in biochemical markers and critically analyse the clinical data assessing the utility of established and novel biochemical markers in RA, SpA and PsA.

Biomarker development for axial spondyloarthritis

The term axial spondyloarthritis (axSpA) encompasses a heterogeneous group of diseases that have variable presentations, extra-articular manifestations and clinical outcomes, and that will respond differently to treatments. The prototypical type of axSpA, ankylosing spondylitis, is thought to be caused by interaction between the genetically primed host immune system and gut microbiota. Currently used biomarkers such as HLA-B27 status, C-reactive protein and erythrocyte sedimentation rate have, at best, moderate diagnostic and predictive value. Improved biomarkers are needed for axSpA to assist with early diagnosis and to better predict treatment responses and long-term outcomes. Advances in a range of 'omics' technologies and statistical approaches, including genomics approaches (such as polygenic risk scores), microbiome profiling and, potentially, transcriptomic, proteomic and metabolomic profiling, are making it possible for more informative biomarker sets to be developed for use in such clinical applications. Future developments in this field will probably involve combinations of biomarkers that require novel statistical approaches to analyse and to produce easy to interpret metrics for clinical application. Large publicly available datasets from well-characterized case-cohort studies that use extensive biological sampling, particularly focusing on early disease and responses to medications, are required to establish successful biomarker discovery and validation programmes.

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.

Spine and Sacroiliac Joints Lesions on Magnetic Resonance Imaging in Early Axial-Spondyloarthritis During 24-Months Follow-Up (Italian Arm of SPACE Study)

Objectives: Our study aimed to identify: (1) the prevalence of spine and pelvis magnetic resonance imaging (MRI-spine and MRI-SIJ) inflammatory and structural lesions in patients (pts) with a diagnosis of axial spondyloarthritis (axSpA); (2) the predictive factors for a severe disease pattern with a higher probability of radiographic progression. Materials and Methods: Seventy-five pts with low back pain (LBP) (≥3 months, ≤2 years, onset ≤45 years) underwent physical examination, questionnaires, laboratory tests, X-rays, MRI-spine, and MRI-SIJ at baseline (T0) and during a 24-months follow-up. Two expert rheumatologists made axSpA diagnosis and classification (according ASAS criteria). MRI-spine, MRI-SIJ and X-rays were scored independently by 2 readers following the SPARCC, mSASSS, and mNY-criteria. According to ASAS criteria, 21 pts fulfilled imaging arm only and 29 clinical arm with/without imaging arm; 25 pts did not fulfill ASAS criteria. Results: At T0 the mean ± SD LBP onset was 28.51 ± 8.05 years, 45.3% pts were male, 38.7% were HLA-B27+; 56% showed bone marrow oedema (BMO) at MRI-spine and 64% at MRI-SIJ. Signs of enthesitis were found in 58% pts in the thoracic spine. Eighteen (24%) pts presented BMO at MRI-spine with a negative MRI-SIJ. The prevalence of BMO lesions and the SPARCC SIJ and spine score decreased during the follow-up in the 2 cohorts meeting ASAS criteria. An early onset of LBP, a lower use of NSAIDs, a BASDAI>4 were identified as predictors of spine structural damage; the high SPARCC SIJ score appeared to be a predictor of SIJ structural damage. A higher mSASSS was predicted by a lower age of onset of LBP. Predictor of higher SPARCC spine was a higher NSAIDs and of higher SPARCC SIJ score the HLA-B27 positivity with increased inflammatory biomarkers. Conclusions: At T0 a significant prevalence of BMO lesions was observed both in SIJ and spine, with predominant involvement of thoracic district. Since positive MRI-spine images were observed in the absence of sacroiliitis, these findings seem to be relevant in the axSpA diagnosis. Early age of disease onset, long duration of LBP, increased inflammatory biomarkers, higher use of NSAIDs, male gender, HLA-B27 positivity, SPARCC SIJ score>2 appeared predictors of radiological damage and activity.

Circulating Retinol-Binding Protein 4 as a Possible Biomarker of Treatment Response for Ankylosing Spondylitis: An Array-Based Comparative Study

Objective

To explore proteins associated with ankylosing spondylitis (AS) and to investigate potential proteins that may predict treatment response of adalimumab (ADA) in AS patients.

Methods

In the discovery cohort, 39 AS patients and 20 healthy controls (HCs) were included, and 16 AS patients received ADA treatment for 24 weeks after included. In the validation cohort, 43 AS patients and 39 HCs were enrolled, and all 43 patients received ADA treatment after enrollment. Blood samples and clinical information were collected from two cohorts at baseline from all participants and week 24 from patients received ADA treatment. A human antibody array containing 1,000 proteins was used in the discovery phase, and Elisa kits were used for protein validation.

Results

Compared with HCs, we identified 53 differentially expressed proteins (DEPs) in AS patients. Bioinformatics analysis revealed they were mostly enriched in coagulation function-related pathways, acute response signaling, and LXR/RXR activation. Bone metabolism pathways were also associated. Comparison between samples of pre- and post-ADA treatment revealed 42 DEPs. They were mostly associated with bone metabolism and inflammation response pathways. Significant enrichment was also found in LXR/RXR activation but not the coagulation function-related pathways. Upstream regulator analysis suggested that most regulators also significantly functioned under usage of ADA. Precisely, seven proteins were abnormally expressed in AS and restored after ADA treatment. Retinol-binding protein 4 (RBP4), one of the seven proteins, was validated that its baseline levels were inversely correlated with improvements in Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP). Likewise, percentage changes in RBP4 levels were inversely correlated with changes in ASDAS-CRP score.

Conclusion

A dysregulated serum protein profile existed in AS. ADA exerted a considerable but not entire alteration toward the dysregulation. RBP4 could be a biomarker for predicting and monitoring ADA treatment response.

Biologic therapy and spinal radiographic progression in patients with axial spondyloarthritis: A structured literature review

We aimed to perform a structured literature review of spinal radiographic progression, as assessed by the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), in patients with ankylosing spondylitis (AS) or nonradiographic axial spondyloarthritis (nr-axSpA) treated with biologic therapy. Searches were limited to English language manuscripts published in the 11 years prior to 9 July 2019. Randomized controlled trials, open-label extensions (OLEs) and observational studies reporting mSASSS progression in patients with AS or nr-axSpA treated with biologics were eligible for inclusion. Bias was assessed using the methodological index for nonrandomized studies (MINORS) tool. Among the 322 studies identified in the literature search, 23 (11 OLEs and 12 cohort studies) met the eligibility criteria and were selected for inclusion. Most studies reported mSASSS progression in patients with AS receiving tumor necrosis factor inhibitor (TNFi) treatment. One study reported mSASSS progression in patients with AS treated with secukinumab, an interleukin-17A inhibitor. The mean (range) MINORS score was 11.3 (7-15) for the 15 noncomparative studies and 15 (12-22) for the 8 comparative studies. Although results of the individual studies were variable, mSASSS progression in patients with AS was generally minimal and slow with long-term TNFi therapy. Moreover, odds ratios for the likelihood of mSASSS progression with/without TNFi favoured TNFi therapy in several of the cohort studies. The rate of mSASSS progression following continuous secukinumab treatment was low and remained stable over 4 years. Of two studies reporting progression in patients with nr-axSpA treated with TNFis, one showed no mSASSS progression; however, the lack of control limited comparative conclusions.

miR-21 may Act as a Potential Mediator Between Inflammation and Abnormal Bone Formation in Ankylosing Spondylitis Based on TNF-α Concentration-Dependent Manner Through the JAK2/STAT3 Pathway

Objective:

To explore the role of microRNA (miR-21) in new bone formation in ankylosing spondylitis (AS) as mediated by different concentration of tumor necrosis factor-α (TNF-α).

Methods:

Fibroblasts isolated from the hips of patients with AS were induced to osteogenesis. These cells were then stimulated with varying concentrations of TNF-α. MicroRNA-21 expressions were evaluated using reverse transcription–polymerase chain reaction (RT-PCR) and osteogenesis was detected via Alizarin Red S (ARS) staining and measurement of alkaline phosphatase (ALP) activity. Relative expressions of p-STAT3, Nuclear STAT3, cytoplasm STAT3, Runx2, BMP2, osteopontin, osteocalcin, and LC3B in AS fibroblasts were measured after exposure to different concentrations of TNF-α. The STAT3-inhibiting small interfering RNA allowed further exploration on its impact on miR-21 and primary miR-21 expressions. A proteoglycan-induced arthritis (PGIA) Balb/c mouse model was established in order to monitor sacroiliac joint (SIJ) inflammation and subsequent damage through magnetic resonance image. Serum miR-21 and TNF-α expressions were evaluated using RT-PCR and enzyme-linked immunosorbent assay. At week 16, mice models were transfected intravenously with miR-21 overexpressing agomir and miR-21 inhibiting antagomir for 7 successive days. The rate of abnormal bone formation at SIJ was evaluated using microcomputed tomography and hematoxylin and eosin staining at week 24. Western blot analysis enabled quantification of STAT-3, JAK-2, and interleukin (IL)-17A expressions present in the SIJ.

Results:

The in vitro miR-21 expression and osteogenesis activity were noted to be augmented in the setting of low TNF-α concentrations (0.01-0.1 ng/mL) while they were depressed in settings with higher TNF-α concentrations (1-10 ng/mL). Samples with the most distinct ARS manifestation and ALP activity as well as the highest miR-21 expressions were those who received 0.1 ng/mL of TNF-α. Primary miR-21 was found to be notable raised by Si-STAT3, while the converse effect was seen in mature miR-21 expressions. Intravenous injection of exogenous miR-21 contributed to new bone formation and significantly elevated expressions of STAT3, JAK2, and IL-17 in PGIA mice.

Conclusions:

The results revealed that miR-21 may act as a potential mediator between new bone formation and inflammation in AS.

Serological Biomarkers in Early Axial Spondyloarthritis During 24-Months Follow Up (Italian Arm of Space Study)

Objectives: The study aimed to evaluate biomarkers facilitating early axial-spondyloarthritis (axSpA) diagnosis and disease activity and imaging indices correlated. Materials and Methods: Seventy-five patients with low back pain (LBP) (≥3 months, ≤2 years, onset ≤45 years) participating in the Italian arm of the SpondyloArthritis-Caught-Early (SPACE) study underwent a physical examination, questionnaires, laboratory tests, spine, and sacroiliac joints (SIJ) X-rays and magnetic resonance imaging (MRI) at baseline and during a 24-months follow-up. Two expert rheumatologists formulated axSpA diagnosis and assessed fulfillment of Assessment of SpondyloArthritis International Society (ASAS) criteria. Disease activity and physical functioning were assessed using imaging, clinical, and serological indices. Spine and SIJ MRI and X-rays were scored independently by 2 readers following the Spondyloarthritis Research Consortium of Canada (SPARCC), mSASSS, and mNY-criteria. Patients were classified in accordance to ASAS criteria as: 21 patients classified according to axSpA imaging arm; 29 patients classified according to axSpA clinical ± imaging arm; 25 patients not fulfilling ASAS criteria. Results: At baseline biomarker levels were not significantly increased in any of the patient groups. Instead, a significant decrease of all functional and disease activity indices from baseline to 24 months was observed in all the three groups. In the same period, there were no significant variation in the serological markers values within each group. The correlations between IL-17 and IL-23 and clinical and functional indices were not significant. On the other hand, significant correlations were found between IL-22 and Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Patient Global Score (BASG1), Health Assessment Questionnaire (HAQ), Visual Analog Scale (VAS pain); MMP3 and mSASSS; MMP3 and hsCRP. Conclusions: Although not significantly higher in any of the cohorts, IL-22, MMP3, and hsCRP values correlated with some disease activity indices and with mSASSS. Further studies are warranted to confirm these preliminary findings.

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.

Humoral and Cellular Patterns of Early Endothelial Progenitor Cells in Relation to the Cardiovascular Risk in Axial Spondylarthritis

Background

Spondylarthritis (SpA) significantly affects sacroiliac, intervertebral and peripheral joints. Patients with SpA suffer from increased cardiovascular risk (CVR). The endothelial progenitor cell (EPC) system critically perpetuates vascular repair. The aim of the study was to evaluate circulating EPCs in axial (ax)SpA with special attention on parameters of disease activity and CVR.

Methods

Disease activity and functional impairment were quantified in 50 axSpA patients by using standardized parameters (Bath ankylosing spondylitis disease activity index (BASDAI), C-reactive protein (CRP), finger-floor distance (FFD) and Ott’ sign). Circulating EPCs and EPC regeneration were analyzed (fluorescence-activated cell sorting (FACS) and colony-forming unit (CFU) assay). Serum vasomodulatory mediators were quantified by enzyme-linked immunosorbent assay (ELISA).

Results

EPC colony numbers were lower in axSpA as compared to controls. Females displayed more colonies than males. In addition, fewer colonies were observed in smokers, in patients with a BASDAI of below 4 and in hypertension. Circulating CD133⁺/KDR⁺ cells did not differ between the groups. Follow-up analysis (33 months later) did not show any differences in gender, colony formation, CD133⁺/KDR⁺ cells or serum levels of vasomodulatory mediators if related to the categories of BASDAI, Ott’ sign or FFD.

Conclusions

EPC colony formation is significantly affected in axSpA with particularly low levels in males. EPC-related parameters do not allow predicting disease activity-related or functional parameters nor are they useful for CVR assessment in SpA.

Aberrant expression of microRNAs in peripheral blood mononuclear cells as candidate biomarkers in patients with axial spondyloarthritis

OBJECTIVES

Axial spondyloarthritis (axSpA) is a chronic inflammatory arthritis involving the axial skeleton. Recent evidence suggests that microRNAs (miRNAs) play a critical role in ankylosing spondylitis (AS). In this study, we aimed to investigate whether miR-17-5p, miR-27a, miR-29a and miR-126-3p can be verified as potential biomarkers of axSpA.

METHODS

Peripheral blood mononuclear cell (PBMC) miRNA expression was evaluated by quantitative real-time polymerase chain reaction among 43 patients with AS, 26 patients with non-radiographic axSpA (nr-axSpA) and 39 healthy controls. Detailed clinical histories were recorded and the correlation of miRNAs and clinical features were analyzed.

RESULTS

When compared to controls, both patients with AS and nr-axSpA had significantly higher expression levels of miR-17-5p, miR-27a, miR-29a and miR-126-3p. MiR-27a was negatively correlated with Ankylosing Spondylitis Disease Activity Score as well as C-reactive protein in patients with nr-axSpA (r = -0.51, P < 0.01 and r = -0.42, P = 0.034 respectively). No other clinical features were found to correlate with the four miRNAs in patients with AS. Mir-29a showed highest area under the curve with 0.952 and these four miRNAs may be potential biomarkers in patients with axSpA.

CONCLUSIONS

We reported elevated miR-17-5p, miR-27a, miR-29a and miR-126-3p expression in PBMCs of patients with axSpA, and the expression of these four miRNAs might be used as useful diagnostic markers in axSpA.

Autoantibodies in Spondyloarthritis, Focusing on Anti-CD74 Antibodies

Spondyloarthritis (SpA) is an inflammatory rheumatic disease with diverse clinical presentation. The diagnosis of SpA remains a big challenge in daily clinical practice because of the limitation in specific biomarkers of SpA, more biomarkers are still needed for SpA diagnosis and disease activity monitoring. In the past, SpA was considered predominantly as auto-inflammatory disease vs. autoimmune disease. However, in recent years several researches demonstrated a broad autoantibody response in SpA patients. Study also indicated that mice lack of ZAP70 in T cell develop SpA featured inflammation. These studies indicated the autoimmune features of SpA and gave rise to the potential use of autoantibody in SpA management. In this article, we reviewed recent reports of autoantibodies associated with SpA patients, revealing the autoimmune features of SpA, suggesting the hypothesis that SpA was also an autoimmune disease, studies about the autoimmune features might provide more insights in the pathogenesis of SpA. In addition, as there are two opposite conclusions in the role of anti-CD74 autoantibody in the diagnosis of SpA, we also gave our own data on the diagnostic value of anti-CD74 in Chinese SpA patients. Though our data indicated that anti-CD74 might not be a good biomarker for SpA diagnosis in Asian people, CD74 was still a good molecule target in the research of SpA pathogenesis.

Is radiographic progression in radiographic axial spondyloarthritis related to matrix metalloproteinase degradation of extracellular matrix?

Background

Radiographic axial spondyloarthritis (r-axSpA) is associated with extracellular matrix (ECM) remodelling of affected tissues. We investigated whether there was a relationship between biomarkers of ECM remodelling and 2-year radiographic progression in r-axSpA.

Methods

Patients from the Outcome in Ankylosing Spondylitis International Study (OASIS) were included if they had serum, clinical and spinal radiographic assessments available at baseline and 2 years later. Two readers independently scored the radiographs according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). The average score was used. Type I, V and VI collagen metabolites (C1M, C5M and C6M) and citrullinated and matrix metalloproteinase-degraded vimentin (VICM) were assessed in serum by ELISAs. The relationship between serum biomarkers and 2-year radiographic progression was investigated using linear regression analyses adjusted for potential confounders. Interactions were tested.

Results

Patients included (n=122) had a mean age of 45 years (SD 12), 70% were male and 82% were human leucocyte antigen-B27 positive. The mean 2-year mSASSS progression was 2.1 (2.9) units. Only C1M was significantly associated with mSASSS progression (β=0.01, 95% CI 0.00 to 0.03). The effect disappeared after adjustment for confounders. C5M, C6M and VICM showed no relationship with mSASSS progression.

Conclusion

We did not find evidence that degradation of ECM is related to radiographic progression in patients with r-axSpA.

Involvement of sphingosine kinase/sphingosine 1-phosphate metabolic pathway in spondyloarthritis

Spondyloarthritis (SpA) is a relatively common chronic inflammatory joint disorder, with a prevalence of about 0.2-0.5% worldwide. The primary target of the pathological process is the enthesis, where tendons and ligaments attach to underlying bone. These insertion sites are hotspots of bone formation (enthesophytes), which can lead to ankylosis. Unfortunately, the mechanisms causing the onset and progression of entheseal ossification remain largely unknown. Sphingosine 1-phosphate (S1P), a lipid generated after sphingosine phosphorylation by sphingosine kinases 1 and 2 (SK1/2), plays important roles in cell proliferation, differentiation and survival. S1P regulates fundamental biological processes such as cell cycle, inflammatory response or bone homeostasis. Indeed, S1P has been involved in some of most-spread skeletal diseases such as rheumatoid arthritis or osteoarthritis. On the other hand, the implication of S1P in SpA has not been explored yet. In the present work, we observed by ELISA that S1P content was significantly increased in the serum of SpA patients (6.1±4.2μM, n=21) compared to healthy donors (1.6±0.9μM, n=12). In vitro, gene expression of SK1 and SK2 as well as their activity were increased during differentiation of primary murine chondrocytes and osteoblasts into mineralizing cells. In addition, mRNA of the S1P-specific transporter Spns2 and S1P secretion were augmented. Using the pharmacological drugs SKi (SK pan-inhibitor), PF-543 (SK1 specific inhibitor) or K-145 (SK2 specific inhibitor), we showed that the inhibition of SK1 and/or SK2 decreased matrix mineralization, alkaline phosphatase activity and the mRNA expression of Runx2 and Bglap in chondrocytes and osteoblasts. To our knowledge, this is the first study indicating that S1P levels are significantly increased in serum from SpA patients. Moreover, we showed in vitro that SK activity was involved in the mineralization capacity of osteoblasts and chondrocytes. S1P metabolic pathway may represent an ingenious therapeutic target for SpA in the future.

Glycoprotein YKL-40: A potential biomarker of disease activity in rheumatoid arthritis during intensive treatment with csDMARDs and infliximab. Evidence from the randomised controlled NEO-RACo trial

OBJECTIVE

YKL-40, a chitinase-like glycoprotein associated with inflammation and tissue remodeling, is produced by joint tissues and recognized as a candidate auto-antigen in rheumatoid arthritis (RA). In the present study, we investigated YKL-40 as a potential biomarker of disease activity in patients with early RA at baseline and during intensive treatment aiming for early remission.

METHODS

Ninety-nine patients with early DMARD-naïve RA participated in the NEO-RACo study. For the first four weeks, the patients were treated with the combination of sulphasalazine, methotrexate, hydroxychloroquine and low dose prednisolone (FIN-RACo DMARD combination), and subsequently randomized to receive placebo or infliximab added on the treatment for further 22 weeks. Disease activity was evaluated using the 28-joint disease activity score and plasma YKL-40 concentrations were measured by immunoassay.

RESULTS

At the baseline, plasma YKL-40 concentration was 57 ± 37 (mean ± SD) ng/ml. YKL-40 was significantly associated with the disease activity score, interleukin-6 and erythrocyte sedimentation rate both at the baseline and during the 26 weeks' treatment. The csDMARD combination decreased YKL-40 levels already during the first four weeks of treatment, and there was no further reduction when the tumour necrosis factor-α antagonist infliximab was added on the combination treatment.

CONCLUSIONS

High YKL-40 levels were found to be associated with disease activity in early DMARD-naïve RA and during intensive treat-to-target therapy. The present results suggest YKL-40 as a useful biomarker of disease activity in RA to be used to steer treatment towards remission.

S100-alarmins: potential therapeutic targets for arthritis

INTRODUCTION

In arthritis, inflammatory processes are triggered by numerous factors that are released from joint tissues, promoting joint destruction and pathological progression. During inflammation, a novel family of pro-inflammatory molecules called alarmins is released, amplifying inflammation and joint damage. Areas covered: With regard to the role of the alarmins S100A8 and S100A9 in the pathogenesis of arthritis, recent advances and the future prospects in terms of therapeutic implications are considered. Expert opinion: There is still an urgent need for novel treatment strategies addressing the local mechanisms of joint inflammation and tissue destruction, offering promising therapeutic alternatives. S100A8 and S100A9, which are the most up-regulated alarmins during arthritis, are endogenous triggers of inflammation, defining these proteins as promising targets for local suppression of arthritis. In murine models, the blockade of S100A8/S100A9 ameliorates inflammatory processes, including arthritis, and there are several lines of evidence that S100-alarmins may already be targeted in therapeutic approaches in man.

Spondyloarthritis: Matrix Metalloproteinasesas Biomarkers of Pathogenesis and Response to Tumor Necrosis Factor (TNF) Inhibitors

The term spondyloarthritis (SpA) is used to describe a group of multifactorial chronic inflammatory diseases characterized by a predisposing genetic background and clinical manifestations typically involving the sacroiliac joint. The absence of pathognomonic clinical and/or laboratory findings generally results in a delay in diagnosis and, consequently, in treatment. In addition, 20–40% of SpA patients are non-responders to tumor necrosis factor (TNF) inhibitor therapies. Given these considerations, it is important to identify biomarkers that can facilitate the diagnosis and assessment of disease activity. As inflammation plays a key role in the pathogenesis of SpA, inflammatory mediators have been investigated as potential biomarkers for diagnosing the disease and predicting response to therapy. Some investigators have focused their attention on the role of matrix metalloproteinases (MMPs), which are known to be markers of synovial inflammation that is generated in the joint in reaction to inflammatory stimuli. Several studies have been carried out to verify if serum MMPs levels could be useful to diagnose SpA, to assess disease severity, and to predict response to TNF inhibitor therapy. The current review focuses on MMPs’ role in SpA pathogenesis, diagnosis and therapeutic implications.

Ultrasonographic evaluation of femoral cartilage thickness in patients with psoriatic arthritis

BACKGROUND

Psoriatic arthritis (PsA) is a common form of arthritis that may vary from asymmetric oligoarthritis to symmetric polyarthritis and spondyloarthritis.

OBJECTIVES

To evaluate femoral cartilage thickness using ultrasonography in patients with PsA.

METHODS

Thirty-three patients (24 female, 9 male) with a diagnosis of PsA and 31 age-, sex- and body mass index-similar healthy subjects were enrolled in this study. Demographic and clinical characteristics of the patients were recorded, including disease duration, morning stiffness and medications. The femoral cartilage thicknesses of both knees (while held in maximum flexion) were measured with a 7-12 MHz linear probe. Three mid-point measurements were taken from both knees (at the lateral condyle, intercondylar area and medial condyle).

RESULTS

Cartilage thicknesses were similar between PsA patients and healthy control subjects. However, there were significant correlations between cartilage thickness and the Maastricht Ankylosing Spondylitis Enthesitis Score, Bath AS functional index and Bath AS disease activity index scores.

CONCLUSION

Femoral cartilage thickness is similar between PsA patients and healthy controls. The femoral cartilage thickness in PsA patients is associated with disease activity, functional inadequacy, and enthesopathy scores.

Serum C-reactive Protein Levels Demonstrate Predictive Value for Radiographic and Magnetic Resonance Imaging Outcomes in Patients with Active Ankylosing Spondylitis Treated with Golimumab

OBJECTIVE

Serum C-reactive protein (CRP) associates with radiographic progression in patients with ankylosing spondylitis (AS) untreated with tumor necrosis factor (TNF) antagonists. We assessed correlations between serum CRP and radiographic progression/magnetic resonance imaging (MRI)-detected inflammation after 2 years of anti-TNF therapy.

METHODS

Patients with active AS receiving golimumab (GOL)/placebo through Week 16 (early escape) or Week 24 (crossover by design), followed by GOL through 4 years, had sera/images obtained through Week 208. Lateral spinal radiographs and spinal MRI were scored with the modified Stoke AS Spine Score (mSASSS) and the AS spine MRI activity (ASspiMRI-a) score, respectively. ANOVA assessed differences based on CRP levels and mSASSS progression. The relationships between CRP levels and mSASSS/ASspiMRI-a were assessed by Spearman correlation and logistic regression.

RESULTS

Of the randomized GO-RAISE patients, 299 (84.0%) had pre- and posttreatment spinal radiographs. Larger proportions of patients with Week 104 CRP ≥ 0.5 mg/dl (n = 47) versus < 0.5 mg/dl (n = 236, 40.4% vs 22.9%, p = 0.0121) had mSASSS changes ≥ 2 at Week 104. Across several visits, serum CRP demonstrated weak associations with mSASSS change (rs ≤ 0.21, p < 0.05, n = 262-293) and moderate associations with ASspiMRI-a change (rs = -0.33 to 0.54, p < 0.05, n = 65-89). Higher baseline CRP was associated with increased risk for syndesmophytes at Week 104/Week 208, and large, short-term decreases in CRP from baseline to Week 14/Week 24 also yielded increased syndesmophyte formation risk.

CONCLUSION

Elevated CRP after 2 years of anti-TNF treatment correlated with greater radiographic progression risk at 4 years. Elevated CRP at baseline or Week 14/Week 24 of anti-TNF treatment weakly predicted subsequent radiographic progression and modestly predicted residual spinal inflammation in patients with AS treated with anti-TNF. Findings are useful regarding new treatment options in patients treated with anti-TNF. ClinicalTrials.gov: NCT00265083.

Serum levels of Dkk-1, sclerostin and VEGF in patients with ankylosing spondylitis and their association with smoking, and clinical, inflammatory and radiographic parameters

OBJECTIVE

To evaluate serum Dickkopf-1 (Dkk-1), sclerostin and vascular endothelial growth factor (VEGF) levels in patients with ankylosing spondylitis (AS) compared to healthy controls as well as their association with smoking, and clinical, inflammatory and radiographic parameters.

METHODS

Serum samples for total Dkk-1, sclerostin and VEGF were obtained from 57 tumour necrosis factor (TNF) inhibitor naïve patients with AS and 34 sex-, age- and body mass index (BMI)-matched controls. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), modified Stroke AS Spine Score (mSASSS) and smoking status were assessed for each patient.

RESULTS

There was no significant difference in serum bone metabolism markers between AS patients and controls. Dkk-1 levels were significantly (P<0.05) higher in AS patients with elevated ESR and CRP and no syndesmophytes, and were significantly (P<0.001) correlated with sclerostin levels (r=0.592). VEGF levels were significantly (P<0.05) higher in AS patients with current and ever smoking, elevated ESR and CRP, and high BASDAI and BASFI, and were significantly (P<0.05) correlated with ESR (r=0.284), CRP (r=0.285), BASDAI (r=0.349) and BASFI (r=0.275). In multivariate regression analyses, high Dkk-1 levels were significantly (P≤0.001) associated with elevated ESR and CRP, no syndesmophytes and high sclerostin levels, and high VEGF levels significantly (P<0.05) with ever smoking, and elevated ESR and CRP.

CONCLUSION

In AS, serum Dkk-1 concentrations appear to be related not only to syndesmophyte formation but also to systemic inflammation. Furthermore, high VEGF levels may be associated with smoking exposure.

Course of Magnetic Resonance Imaging-Detected Inflammation and Structural Lesions in the Sacroiliac Joints of Patients in the Randomized, Double-Blind, Placebo-Controlled Danish Multicenter Study of Adalimumab in Spondyloarthritis, as Assessed by the Berlin and Spondyloarthritis Research Consortium of Canada Methods

OBJECTIVE

To investigate changes in magnetic resonance imaging (MRI)-assessed inflammation and structural lesions in the sacroiliac (SI) joints during treatment with adalimumab versus placebo.

METHODS

In a 48-week double-blind, placebo-controlled trial, 52 patients with spondyloarthritis were randomized to receive subcutaneous injections of either adalimumab 40 mg (n = 25) or placebo (n = 27) every other week for 12 weeks. Patients in the adalimumab group continued to receive and patients in the placebo group were switched to adalimumab 40 mg every other week for an additional 12 weeks. MRI of the SI joints was performed at weeks 0, 12, 24, and 48, and the images were assessed independently in a blinded manner using the modified Berlin and the Spondyloarthritis Research Consortium of Canada (SPARCC) MRI scores for inflammation and structural lesions of the SI joints.

RESULTS

At baseline, 56% of the adalimumab group and ∼72% of the placebo group had an MRI-assessed inflammation score of ≥1. Among the patients with inflammation at baseline, the mean percent reductions in MRI scores for inflammation from week 0 to 12 were greater in the adalimumab group compared with the placebo group (Berlin method, -62% versus -5%; SPARCC method, -58% versus -12% [both P < 0.04]). Furthermore, the mean SPARCC erosion score decreased (-0.6) and the SPARCC backfill score increased (+0.8) in the adalimumab group from week 0 to week 12. From week 12 to week 24, larger absolute reductions in the Berlin/SPARCC inflammation scores and the SPARCC erosion score and larger increases in the Berlin/SPARCC fatty lesion scores were seen in the placebo group compared with the adalimumab group. In univariate regression analyses (analysis of covariance) and multivariate stepwise regression analyses, treatment with adalimumab was independently associated with regression of the SPARCC erosion score from week 0 to 12 but not with changes in the other types of MRI lesions.

CONCLUSION

Significant changes in the Berlin and SPARCC MRI-assessed inflammation scores and in the SPARCC MRI-assessed erosion scores occurred within 12 weeks after initiation of adalimumab. Tumor necrosis factor inhibitor treatment was associated with resolution of erosions and the development of backfill.

Association Between Intercellular Adhesion Molecule-1, -2, -3 Plasma Levels and Disease Activity of Ankylosing Spondylitis in the Chinese Han Population

STUDY DESIGN

We investigated the association between ICAM-1, -2, -3 plasma levels and ankylosing spondylitis (AS) disease activity.

OBJECTIVE

In the present study, we aimed to investigate the association between ICAM-1, -2, -3 plasma levels and AS disease activity in the Chinese Han population.

SUMMARY OF BACKGROUND DATA

AS is a chronic inflammatory rheumatic disease that effects the sacroiliac joints and axial skeleton. The intercellular adhesion molecules (ICAMs) are members of the immunoglobulin superfamily and have been identified to play major roles in inflammation and immune responses.

METHODS

A total of 60 patients with AS and 60 healthy individuals were selected. The plasma levels of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and ICAM-1, -2, -3, were analyzed by ELISA. Disease severity-related indexes, including the Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), and ankylosing spondylitis disease activity score (ASDAS), were assessed, along with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level.

RESULTS

Both ICAM-1 and ICAM-2 levels in plasma were markedly increased in AS patients compared with levels in the plasma of controls. There was no difference between controls and patients in term of ICAM-3 levels. Furthermore, in patients, correlation analysis showed that TNF-α and IL-6 production, as well as the ESR and CRP levels, have positive relationships with ICAM-1 and ICAM-2 plasma levels; the BASDAI, BASFI, and ASDAS scores were also found to be positively correlated with ICAM-2. However, no significant correlations between ICAM-1 levels and BASDAI, BASFI, or ASDAS were detected in our study.

CONCLUSION

The current findings suggest that ICAM-2 may be a potential biomarker reflecting disease activity and functional ability in AS patients.

LEVEL OF EVIDENCE

5.

Alteration of Bone Turnover Markers in Canonical Wingless Pathway in Patients With Ankylosing Spondylitis

Objectives

This study aims to determine the levels of bone turnover markers in canonical wingless pathway in patients with ankylosing spondylitis (AS) and the correlation with disease activity indexes.

Patients and methods

We recruited a total of 43 AS patients (34 males, 8 females; mean age 36.8±9.3 years; range 22 to 62 years) and age- and sex-matched 42 healthy controls (32 males, 10 females; mean age 36.1±9.7; range 24 to 59 years). Serum levels of components of canonical wingless pathway including Dickkopf-1, glycogen synthase kinase-3β, β-catenin, alkaline phosphatase, and osteocalcin were detected using enzyme- linked immunosorbent assay method. All patients were assessed in terms of erythrocyte sedimentation rate, C-reactive protein, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Ankylosing Spondylitis Disease Activity Score, and the modified Stoke's Ankylosing Spondylitis Spine Score. Pearson's correlation test was used to analyze the correlation between serum bone turnover markers and clinical assessment indexes.

Results

No significant difference was observed between AS patients and healthy controls for the levels of glycogen synthase kinase-3β, β-catenin, alkaline phosphatase, and osteocalcin, respectively (p>0.05). The level of Dickkopf-1 was significantly higher in AS patients (1914.5±407.8 pg/mL) than in healthy controls (1729.1±352.9 pg/mL) (p<0.05). There was no correlation between high Dickkopf-1 level and any of the clinical parameters contributing to inflammation or bone formation. However, the correlation between osteocalcin and disease duration was significant in AS patients (r=0.323, p=0.034).

Conclusion

Alteration of bone turnover markers in canonical wingless pathway was observed in AS. This might partially explain the complicated mechanism of bone formation in the disease.

CRP and a biomarker of type I collagen degradation, C1M, can differentiate anti-inflammatory treatment response in ankylosing spondylitis

Aim: To investigate if tissue turnover biomarkers were efficacy biomarkers in ankylosing spondylitis and if the biomarkers at baseline predicted a good outcome (BASDAI50). Patients & methods: Twenty-two etanercept treated ankylosing spondylitis patients were investigated for inflammation (CRP, ESR, CRPM) and tissue turnover (C1M, C2M, C3M) during the first year of treatment. Biomarkers profiles and treatment response were investigated. Results: ESR, CRP, BASDAI and C1M were decreased with treatment (p ≤ 0.04). C1M and CRP segregated patients into two populations predicting treatment efficacy. Conclusion: C1M and CRP were efficacy biomarkers and baseline biomarkers could select who benefited (by biomarkers) from treatment. C1M was not superior to CRP, but the biomarkers evaluate different pathologic events, indicating that C1M and CRP identify different events.

Calprotectin in rheumatic diseases

Calprotectin is a heterodimer formed by two proteins, S100A8 and S100A9, which are mainly produced by activated monocytes and neutrophils in the circulation and in inflamed tissues. The implication of calprotectin in the inflammatory process has already been demonstrated, but its role in the pathogenesis, diagnosis, and monitoring of rheumatic diseases has gained great attention in recent years. Calprotectin, being stable at room temperature, is a candidate biomarker for the follow-up of disease activity in many autoimmune disorders, where it can predict response to treatment or disease relapse. There is evidence that a number of immunomodulators, including TNF-α inhibitors, may reduce calprotectin expression. S100A8 and S100A9 have a potential role as a target of treatment in murine models of autoimmune disorders, since the direct or indirect blockade of these proteins results in amelioration of the disease process. In this review, we will go over the biologic functions of calprotectin which might be involved in the etiology of rheumatic disorders. We will also report evidence of its potential use as a disease biomarker. Impact statement Calprotectin is an acute-phase protein produced by monocytes and neutrophils in the circulation and inflamed tissues. Calprotectin seems to be more sensitive than CRP, being able to detect minimal residual inflammation and is a candidate biomarker in inflammatory diseases. High serum levels are associated with some severe manifestations of rheumatic diseases, such as glomerulonephritis and lung fibrosis. Calprotectin levels in other fluids, such as saliva and synovial fluid, might be helpful in the diagnosis of rheumatic diseases. Of interest is also the potential role of calprotectin as a target of treatment.

Effect of Tumor Necrosis Factor Inhibitor Therapy on Osteoclasts Precursors in Ankylosing Spondylitis

Introduction

Ankylosing Spondylitis (AS) is characterized by excessive local bone formation and concomitant systemic bone loss. Tumor necrosis factor (TNF) plays a central role in the inflammation of axial skeleton and enthesis of AS patients. Despite reduction of inflammation and systemic bone loss, AS patients treated with TNF inhibitors (TNFi) have ongoing local bone formation. The aim of this study was to assess the effect of TNFi in the differentiation and activity of osteoclasts (OC) in AS patients.

Methods

13 AS patients treated with TNFi were analyzed at baseline and after a minimum follow-up period of 6 months. 25 healthy donors were recruited as controls. Blood samples were collected to assess receptor activator of nuclear factor kappa-B ligand (RANKL) surface expression on circulating leukocytes and frequency and phenotype of monocyte subpopulations. Quantification of serum levels of bone turnover markers and cytokines, in vitro OC differentiation assay and qRT-PCR for OC specific genes were performed.

Results

RANKL⁺ circulating lymphocytes (B and T cells) and IL-17A, IL-23 and TGF-β levels were decreased after TNFi treatment. We found no differences in the frequency of the different monocyte subpopulations, however, we found decreased expression of CCR2 and increased expression of CD62L after TNFi treatment. OC number was reduced in patients at baseline when compared to controls. OC specific gene expression was reduced in circulating OC precursors after TNFi treatment. However, when cultured in OC differentiating conditions, OC precursors from AS TNFi-treated patients showed increased activity as compared to baseline.

Conclusion

In AS patients, TNFi treatment reduces systemic pro osteoclastogenic stimuli. However, OC precursors from AS patients exposed to TNFi therapy have increased in vitro activity in response to osteoclastogenic stimuli.

Effects of tumor necrosis factor-α inhibitors on new bone formation in ankylosing spondylitis

OBJECTIVES

To better understand the effect of TNF-α inhibitors (TNFi) on new bone formation in ankylosing spondylitis (AS) patients.

METHODS

We systematically searched the articles in EMBASE and PubMed.

RESULTS

Fifteen articles were enrolled. In all the 9 TNFi-treated cohorts, the vertebral corners with inflammatory lesions at baseline were at higher risk to develop new syndesmophytes than those without inflammatory lesions, although a few syndesmophytes also developed at the vertebral corners without inflammatory lesions at baseline. The advanced inflammatory lesions including fat deposition on baseline MRI showed a higher risk for syndesmophyte formation than the acute inflammatory lesions. Because the number of analyzed vertebral corners were too small, it might not be true that new syndesmophytes developed more frequently at the corners with inflammatory lesions completely resolved than those with persistent inflammation after TNFi treatment. Four studies with 2-year follow-up revealed null effect of TNFi on radiographic progression compared with historical controls with lower disease activity, and 3 studies with ≥4-year follow-up proved inhibitory effect of TNFi on new bone formation in AS patients. Patients with a delay of >10 years in starting TNFi therapy were more likely to experience radiographic progression as compared to those who started earlier.

CONCLUSIONS

In TNFi treated AS patients, baseline inflammation is linked with syndesmophyte development. An earlier initiation of TNFi therapy may slow the radiographic progression in AS, and TNFi may lose its benefit of retarding new bone formation at advanced stage of AS especially after the focal fat infiltration or syndesmophyte formation.

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.

Biomarkers in rheumatic diseases: how can they facilitate diagnosis and assessment of disease activity?

Serological and proteomic biomarkers can help clinicians diagnose rheumatic diseases earlier and assess disease activity more accurately. These markers have been incorporated into the recently revised classification criteria of several diseases to enable early diagnosis and timely initiation of treatment. Furthermore, they also facilitate more accurate subclassification and more focused monitoring for the detection of certain disease manifestations, such as lung and renal involvement. These biomarkers can also make the assessment of disease activity and treatment response more reliable. Simultaneously, several new serological and proteomic biomarkers have become available in the routine clinical setting--for example, a protein biomarker panel for rheumatoid arthritis and a myositis antibody panel for dermatomyositis and polymyositis. This review will focus on commercially available antibody and proteomic biomarkers in rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis (scleroderma), dermatomyositis and polymyositis, and axial spondyloarthritis (including ankylosing spondylitis). It will discuss how these markers can facilitate early diagnosis as well as more accurate subclassification and assessment of disease activity in the clinical setting. The ultimate goal of current and future biomarkers in rheumatic diseases is to enable early detection of these diseases and their clinical manifestations, and to provide effective monitoring and treatment regimens that are tailored to each patient's needs and prognosis.

Fat Metaplasia on Sacroiliac Joint Magnetic Resonance Imaging at Baseline Is Associated with Spinal Radiographic Progression in Patients with Axial Spondyloarthritis

Objective

To study the relationship between inflammatory and structural lesions in the sacroiliac joints (SIJs) on MRI and spinal progression observed on conventional radiographs in patients with axial spondyloarthritis (axSpA).

Methods

One hundred and ten patients who fulfilled the ASAS axSpA criteria were enrolled. All underwent SIJ MRI at baseline and lumbar spine radiographs at baseline and after 2 years. Inflammatory and structural lesions on SIJ MRI were scored using the SPondyloArthritis Research Consortium of Canada (SPARCC) method. Spinal radiographs were scored using the Stoke AS Spinal Score (SASSS). Multivariate logistic regression analysis was performed to identify predictors of spinal progression.

Results

Among the 110 patients, 25 (23%) showed significant radiographic progression (change of SASSS≥2) over 2 years. There was no change in the SASSS over 2 years according to the type of inflammatory lesion. Patients with fat metaplasia or ankyloses on baseline MRI showed a significantly higher SASSS at 2 years than those without (p<0.001). According to univariate logistic regression analysis, age at diagnosis, HLA-B27 positivity, the presence of fat metaplasia, erosion, and ankyloses on SIJ MRI, increased baseline CRP levels, and the presence of syndesmophytes at baseline were associated with spinal progression over 2 years. Multivariate analysis identified syndesmophytes and severe fat metaplasia on baseline SIJ MRI as predictive of spinal radiographic progression (OR, 14.74 and 5.66, respectively).

Conclusion

Inflammatory lesions in the SIJs on baseline MRI were not associated with spinal radiographic progression. However, fat metaplasia at baseline was significantly associated with spinal progression after 2 years.

Inflammation: a culprit for vascular calcification in atherosclerosis and diabetes

It is today acknowledged that aging is associated with a low-grade chronic inflammatory status, and that inflammation exacerbates age-related diseases such as osteoporosis, Alzheimer's disease, atherosclerosis and type 2 diabetes mellitus (T2DM). Vascular calcification is a complication that also occurs during aging, in particular in association with atherosclerosis and T2DM. Recent studies provided compelling evidence that vascular calcification is associated with inflammatory status and is enhanced by inflammatory cytokines. In the present review, we propose on one hand to highlight the most important and recent findings on the cellular and molecular mechanisms of vascular inflammation in atherosclerosis and T2DM. On the other hand, we will present the effects of inflammatory mediators on the trans-differentiation of vascular smooth muscle cell and on the deposition of crystals. Since vascular calcification significantly impacts morbidity and mortality in affected individuals, a better understanding of its induction and development will pave the way to develop new therapeutic strategies.

Biomarkers for diagnosis, monitoring of progression, and treatment responses in ankylosing spondylitis and axial spondyloarthritis

With the growing awareness of the impact of chronic back pain and axial spondyloarthritis and recent breakthroughs in genetics and the development of novel treatments which may impact best on early disease, the need for markers that can facilitate early diagnosis and profiling those individuals at the highest risk for a bad outcome has never been greater. The genetic basis of ankylosing spondylitis has been considerably advanced, and HLA-B27 testing has a role in the diagnosis. Knowledge is still incomplete of the rest of the genetic contribution to disease susceptibility, and it is likely premature to use extensive genetic testing (other than HLA-B27) for diagnosis. Serum and plasma biomarkers have been examined extensively in assessing disease activity, treatment response, and as predictors or radiographic severity. For assessing disease activity, other than C-reactive protein and erythrocyte sedimentation rate, the most work has been in examining cytokines (particularly interleukin 17 and 23), matrix metalloproteinase (MMP) markers (particularly MMP3). For assessing those at the highest risk for radiographic progression, biomarkers of bony metabolism, cartilage and connective tissue degradation products, and adipokines have been most extensively assessed. The problem is that no individual biomarkers has been reproducibly shown to assess disease activity or predict outcome, and this area still remains an unmet need, of relevance to industry stakeholders, to regulatory bodies, to the healthcare system, to academic investigators, and finally to patients and providers.