E af Klint

Methothrexate directly inhibits RANKL expression and osteoclast formation in very early arthritis

Methotrexate (MTX) is one of the most widely used therapies in rheumatoid arthritis (RA) due to its anti-inflammatory and potential bone protection effect. Bone biology is governed by the RANKL/RANK/OPG system that determines the balance between bone formation by osteoblasts and bone resorption by osteoclasts. We investigated the effects of MTX on the RANKL/RANK/OPG system in vivo and in vitro. 16 patients with newly diagnosed RA (mean disease duration 1 week) were started …

Effects of anti-rheumatic treatments on expression of microsomal prostaglandin E synthase-1 in rheumatoid arthritis synovium

OBJECTIVE Microsomal prostaglandin E synthase 1 (mPGES-1) catalyzes the formation of PGE(2) from cyclooxygenase-derived PGH(2). Microsomal PGES-1 is induced by proinflammatory cytokines and is strongly linked to conditions that result in high PGE(2) biosynthesis. PGE(2) contributes to the pathogenesis of rheumatoid arthritis (RA), acting as a mediator of inflammation and promoting bone destruction. Induction of mPGES-1 in rheumatoid synoviocytes by proinflammatory cytokines has been demonstrated in vitro, indicating an important role in RA pathogenesis. Recent studies using mPGES-1-deficient mice demonstrated the importance of this gene in chronic inflammation. The aim of this study was to investigate the expression and localization of mPGES-1 in synovial biopsy specimens obtained from patients with RA. METHODS Synovial tissue samples from 24 patients with RA were obtained, and immunohistologic analysis was performed using polyclonal antibodies against mPGES-1. Double immunofluorescence staining was performed with antibodies to CD3, CD19, CD20, CD68, CD163, and prolyl 4-hydroxylase. RESULTS Intracellular mPGES-1 staining was observed in synovial membranes from all of the RA patients studied. Specifically, strong expression of mPGES-1 was detected in synovial lining cells. In sublining mononuclear and fibroblast-like cells, the extent of mPGES-1 staining was less than that in the synovial lining cells. In some patients, positive staining was observed in endothelial cells. With the double immunofluorescence technique, mPGES-1 production was detected in synovial macrophages and fibroblasts, while mPGES-1 expression was not observed in lymphocytes. CONCLUSION The demonstration of mPGES-1 expression in synovial tissues from patients with RA suggests a role for mPGES-1 in the RA disease process. Microsomal PGES-1 might be a potential new target for treatment strategies to control PGE(2) synthesis in patients with RA, without the systemic side effects associated with cyclooxygenase inhibitors.

SAT0093 Hand Joint Inflammation on Fluorescence Optical Imaging Reveal Distinct Patterns in Seropositive and Seronegative Early Rheumatoid Arthritis

Background Detection of abnormal Rheumatoid Arthritis (RA) related autoantibodies, Rheumatoid Factor (RF) and Anti-Citrullinated Peptide Antibody (ACPA), along with Musculoskeletal ultrasound (MSUS) play a critical role in the diagnosis of early RA (eRA). Fluorescence optical imaging (FOI) is an emerging modality designed for the hands and wrists that detects subclinical hand joint inflammation1 and may therefore prove valuable in the assessment of eRA. Objectives Here, we analyzed the FOI results of eRA patients and investigate whether patterns of hand joint inflammation may distinguish seropositive from seronegative RA. Methods In FOI, Inflammation is considered positive, when altered microcirculation (capillary leakage/perfusion) is seen as abnormally increased focal optical signal intensities by visual inspection of the entire image series in real-time (360 seconds all 34 joints: 3 wrists, 5 MCPs, 5 PIPs and 4 DIPs, bilaterally are evaluated using post-processing imaging techniques). Unsupervised ascending hierarchical clustering was used to identify clusters of patients with different patterns of joint involvement in FOI. The robustness of the clustering was verified using another clustering method (k-means), and agreement between the 2 methods was assessed using Cohens kappa. Baseline clinical and biological characteristics of patients were compared between the clusters using non-parametric tests. Results Out of 1326 joints of 39 eRA patients (26 females; 9 with erosive RA; 54% RF+; and 69% ACPA+), 400 (30%) were considered positively inflamed by FOI. The mean (±SD) number of active joints detected by FOI was 10.3 ± 7.2. Clustering of joint involvement according to the FOI distinguished 2 separate clusters of patients: Cluster1 (n=29) and Cluster2 (n=10). The proportion of seropositive patients was significantly higher in cluster 1 versus cluster 2 (26/29 versus 3/10, p<0.01) (figure). The distribution of inflammation throughout the joints, except for right MCP2, PIPs 5, left MCP1 & DIPs in cluster 2 displayed distinguishable patterns (p<0.05) compared to cluster 1, which showed joint inflammation to be largely concentrated around wrists, right MCP2, bilateral MCP3, and to a lesser degree around PIPs 2–4, and left MCP2. The DIPs showed no significant differences between clusters. Conclusions Two separate patterns of inflammatory joint involvement may be distinguished in early RA, using fluorescence optical imaging. The proportion of seropositive patients was significantly different between these patterns, suggesting that FOI identifies patterns of joint involvement that are different for seropositive and seronegative RA. References Kisten Y, Györi N, af Klint E, et al. 2015 Detection of clinically manifest and silent synovitis in the hands and wrists by fluorescence optical imaging. RMD Open 2015;1: e000106. doi:10.1136/ rmdopen-2015-000106 (http://rmdopen.bmj.com/content/1/1/e000106.full.pdf+html) Disclosure of Interest None declared

THU0455 Evaluating Psoriatic Skin Lesions in Psoriasis and Psoriatic Arthritis: Ultrasound as A Complementary Measure

Background Currently, the diagnosis and assessment of psoriatic arthritis (PsA) and psoriasis (PsO) skin lesions are mostly done by visual inspections, and when in doubt, supplemented by biopsies. Although PsA is primarily assessed by physical examination, the utility of ultrasound (US) is beneficial. Objectives The aim of this proof of concept study was to determine the performance of ultrasound (using advanced imaging software applications) in assessing skin lesions and inflammation in selected PsA and PsO patients. Methods A rheumatologist and dermatologist assessed the PsA and PsO patients respectively. PsA examination included the standard clinical joint assessments, and we thereafter evaluated the hands & wrists and symptomatic joints with US for synovitis & tenosynovitis (including nail beds & tendons). Blinded by the clinical results and treatment plans, the epidermal, dermal and subcutaneous tissue thicknesses of 2 of the most affected psoriasis lesions were US scanned using high frequency B-Mode, automated Color Doppler quantification (CDQ; measured over 4 seconds) and elastography applications (measuring lesion size, depth, hyperemia and tissue elasticity). The skin tissue adjacent to the psoriasis lesions, as well as the unaffected skin on the contralateral side (self-control) was measured. Results A total of 270 skin depth measurements (2 of the most affected lesions, 3 intervals apart, at 3 different sites described above) of 5 PsA/PsO patients were analyzed. Epidermal thickness differed significantly between the adjacent and control tissue layers [F (2,27) =30.95, MSE =0.76, p<0.001]. Similar findings were evident for dermal thickness differences [F (2,27) =5.05, MSE =1.59, p=0.014]. In contrast and as expected, subcutaneous tissue thicknesses showed no significant differences. US using color Doppler revealed the presence of hyperemia in 80% of the examined lesions by CDQ resulted in flow averages ranging from 0.016–0.655 for minimum ratios to 0.103–0.241 for maximum ratios. Of these Doppler active lesions, 60% were echogenic (some with acoustic shadowing). Contrary, 20% of the psoriasis lesions showed no obvious Doppler activity, displaying reduced tissue stiffening on elastography (suggesting healed lesions). Two of 10 (20%) lesions showed no abnormal findings (soft on elastography) having no acoustic shadows, and low-level CDQ activity (minimum 0.016:0.034 and maximum 0.103:0.135 ratios). Ultrasound displayed the presence of synovitis, tenosynovitis, and nail-bed hyperemia together with altered microcirculation & hand psoriasis skin perfusion in PsA patients. Conclusions Ultrasound metrics of skin tissue (plaque characteristics, tissue depth & elasticity, and Doppler activity quantification) has potential as a complementary measure for the clinical assessment of PsA and PsO. Disclosure of Interest None declared

AB0981 Hand Joint Inflammation in Early Ra: Clinical Ultrasound and Fluorescence Optical Imaging Diagnostics

Background Altered microcirculation (abnormal perfusion/capillary leakage) of synovial tissue can be detected early using Fluorescence Optical Imaging (FOI). FOI utilizes an intravenous fluorophore1,2 that displays high-resolution hand images that can be analyzed visually (FOI-v) in real-time, or by using digital Disease ACTivity (DACT) scoring methods. We previously reported FOIs sensitivity and specificity in detecting silent synovitis in various rheumatic diseases1. Objectives Here, we test the diagnostic performance of FOI-DACT in detecting subtle hand joint inflammation in early rheumatoid arthritis (eRA), as compared to clinical evaluation and MusculoSkeletal UltraSound (MSUS). Methods Fingers and wrists of patients with eRA were assessed by clinical examination, MSUS and FOI-DACT imaging. Inflammation was defined as having synovial hypertrophy/effusions and intra-articular Doppler signaling on MSUS, and as increased optical intensities on FOI-v. Scores of DACT≥1 were considered indicative of disease activity. Results 1326 joints of 39 eRA patients [72% females, 56% previous/current smokers, 54% RF(+) and 69% ACPA(+)] were studied. The incidence and mean number ±SD of joints inflamed by clinical, MSUS and FOI-v were 23% (7.8±8.1), 29% (9.7±7.7) and 30% (10.3±7.2), respectively. Using MSUS as a reference, FOI-DACT was 95% (35/37) accurate in identifying patients with active disease, 24% (9/37) of whom had erosive RA. High correlations and agreements emerged between MSUS and FOI-v (r=0.803, p<0.001; kappa±SE:0.70±0.02 [95% CI 0.67–0.75]), clinical and FOI-v (r=0.732, p<0.001; kappa±SE:0.56±0.03 [95% CI 0.51–0.61]) and MSUS and clinical (r=0.793, p<0.001; kappa±SE:0.59±0.03 [95% CI 0.54–0.64]). The sensitivity, specificity, NPV and PPV of inflammation by FOI-v was 81% (308/380), 90% (854/946), 61%, and 96% respectively. Of the clinically negative but MSUS positive (145/1023) joints, 68% (Subclinical: 98/145) were also FOI positive. Remarkably, one patient had 15 joints that were FOI-DACT positive and MSUS negative, but a month later, the same joints became MSUS positive. Although the wrists and MCPs were frequently inflamed, DIP joint inflammation was noted in 12 patients by FOI-DACT and MSUS. Nine of these patients had osteoarthritis by conventional radiography. Conclusions In early RA, Fluorescence Optical Imaging (FOI) coupled with digital Disease ACTivity (DACT) scoring correlates well with MSUS, and has a high positive predictive value. FOI-DACT emerges as a useful automated quantitative scoring method for synovial inflammation, and may be used in monitoring the effects of therapy. References Kisten Y, Györi N, af Klint E, et al. 2015 Detection of clinically manifest and silent synovitis in the hands and wrists by fluorescence optical imaging. RMD Open 2015;1: e000106. doi: 10.1136/rmdopen-2015-000106 (http://rmdopen.bmj.com/content/1/1/e000106.full.pdf+html) Glimm AM, Werner SG, et al. Analysis of distribution and severity of inflammation in patients with osteoarthitis compared to rheumatoid arthritis by ICG-enhanced fluorescence optical imaging and musculoskeletal ultrasound: a pilot study. Annals of the Rheumatic Diseases. Published online Aug. 26, 2015. (http://dx.doi.org/10.1136/annrheumdis-2015-207345). Disclosure of Interest None declared

FRI0506 The diagnostic utility of musculoskeletal ultrasound in early arthritis – a probabilistic (bayesian) approach

Background While musculoskeletal ultrasound examination (MSUS) is used increasingly in the work-up of patients with inflammatory joint disease, the exact diagnostic utility has not been established. Objectives To quantify the diagnostic utility of MSUS using a prospective, probabilistic (Bayesian) approach. Methods All patients referred to our clinic for evaluation of arthritis were eligible, unless a prior diagnosis was indicated or a certain diagnosis could be made based on the information in the referral letter. Patients were assessed by history and physical examination including joint examination, laboratory testing including acute-phase reactants, RF, and ACPA, and plain x-ray of hands, wrists and feet if clinically indicated. A diagnostic assessment was then performed by the responsible physician where the probability of a) any inflammatory joint disease and b) rheumatoid arthritis was given on a 5-point scale ranging from unlikely (0-20% probability) to very likely (80-100% probability). Subsequently, an ultrasound examination of the wrist, MCP, PIP 2-5 in both hands, MTP 2-5 in both feet and also symptomatic joints was performed by HR and the results of the examination presented to the responsible physician. The latter then assessed the diagnostic probabilities again, using the same scale. The proportions of patients with maximal and minimal diagnostic certainty pre-test and post-test were compared by Fisher exact test. Results 67 patients were included, 52 were female, average (SD) age 47.9 (16.5) years. Symptom duration 8.9 (4.0) months, 15 patients were positive for RF and 12 for ACPA. The pre-test and post-test probability distributions for (any) inflammatory joint disease and for RA are given in the table. The final diagnoses in these patients were RA (15), other inflammatory joint diseases (21), non-inflammatory joint disease (31). With regard to a diagnosis of (any) inflammatory joint disease, the proportion of patient for whom diagnostic certainty was maximal (<20% OR >80% likelihood) was 20/67 (29.9%) before MSUS and 42/67 (62.7%) after MSUS (p=0.0002). With regard to a diagnosis of RA, the proportions were 21/67 (31.3%) pre-test and 39/67 (58.2%) post-test (p=0.003). Parallel reductions were seen in the proportions of patients with greatest diagnostic uncertainty (40-60% likelihood), from 24/67 (35.8%) to 10/67 (14.9%) (p=0.0093) and from 17/67 (25.3%) to 4/67 (6.0%) (p=0.0035), respectively. Conclusions In this probabilistic (Bayesian) analysis, musculoskeletal ultrasound when added to routine physical and laboratory examination greatly increased the diagnostic certainty in patients referred for the evaluation of arthritis. Disclosure of Interest H. Rezaei: None Declared, E. af Klint: None Declared, R. Van Vollenhoven Grant/research support from: AbbVie, BMS, GSK, MSD, Pfizer, Roche, UCB, Consultant for: AbbVie, BMS, GSK, MSD, Pfizer, Roche, UCB

Differential gene expression and protein expression levels of MMP and TIMP molecules in response to glucocorticoid treatment in arthritic patients

Differential gene expression and protein expression levels of MMP and TIMP molecules in response to glucocorticoid treatment in arthritic patients