Imaging technologies for preclinical models of bone and joint disorders

Preclinical models for musculoskeletal disorders are critical for understanding the pathogenesis of bone and joint disorders in humans and the development of effective therapies. The assessment of these models primarily relies on morphological analysis which remains time consuming and costly, requiring large numbers of animals to be tested through different stages of the disease. The implementation of preclinical imaging represents a keystone in the refinement of animal models allowing longitudinal studies and enabling a powerful, non-invasive and clinically translatable way for monitoring disease progression in real time. Our aim is to highlight examples that demonstrate the advantages and limitations of different imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), single-photon emission computed tomography (SPECT) and optical imaging. All of which are in current use in preclinical skeletal research. MRI can provide high resolution of soft tissue structures, but imaging requires comparatively long acquisition times; hence, animals require long-term anaesthesia. CT is extensively used in bone and joint disorders providing excellent spatial resolution and good contrast for bone imaging. Despite its excellent structural assessment of mineralized structures, CT does not provide in vivo functional information of ongoing biological processes. Nuclear medicine is a very promising tool for investigating functional and molecular processes in vivo with new tracers becoming available as biomarkers. The combined use of imaging modalities also holds significant potential for the assessment of disease pathogenesis in animal models of musculoskeletal disorders, minimising the use of conventional invasive methods and animal redundancy

Human epidermal growth factor receptor bispecific ligand trap RB200: abrogation of collagen-induced arthritis in combination with tumour necrosis factor blockade

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic disease associated with inflammation and destruction of bone and cartilage. Although inhibition of TNFα is widely used to treat RA, a significant number of patients do not respond to TNFα blockade, and therefore there is a compelling need to continue to identify alternative therapeutic strategies for treating chronic inflammatory diseases such as RA. The anti-epidermal growth factor (anti-EGF) receptor antibody trastuzumab has revolutionised the treatment of patients with EGF receptor-positive breast cancer. Expression of EGF ligands and receptors (known as HER) has also been documented in RA. The highly unique compound RB200 is a bispecific ligand trap that is composed of full-length extracellular domains of HER1 and HER3 EGF receptors. Because of its pan-HER specificity, RB200 inhibits responses mediated by HER1, HER2 and HER3 in vitro and in vivo. The objective of this study was to assess the effect of RB200 combined with TNF blockade in a murine collagen-induced arthritis (CIA) model of RA. METHODS: Arthritic mice were treated with RB200 alone or in combination with the TNF receptor fusion protein etanercept. We performed immunohistochemistry to assess CD31 and in vivo fluorescent imaging using anti-E-selectin antibody labelled with fluorescent dye to elucidate the effect of RB200 on the vasculature in CIA. RESULTS: RB200 significantly abrogated CIA by reducing paw swelling and clinical scores. Importantly, low-dose RB200 combined with a suboptimal dose of etanercept led to complete abrogation of arthritis. Moreover, the combination of RB200 with etanercept abrogated the intensity of the E-selectin-targeted signal to the level seen in control animals not immunised to CIA. CONCLUSIONS: The human pan-EGF receptor bispecific ligand trap RB200, when combined with low-dose etanercept, abrogates CIA, suggesting that inhibition of events downstream of EGF receptor activation, in combination with TNFα inhibitors, may hold promise as a future therapy for patients with RA

Concurrent Oral 9 - Rheumatoid Arthritis: Aetiopathogenesis [OP59-OP64]: OP59. The Value of Interleukin-17 Serum Level in Rheumatoid Arthritis Immunopathogenesis

Background: Interleukin (IL)-17 is the main Th-1 cytokine, produced by activated T-lymphocytes. The potential IL-17 value in rheumatoid arthritis (RA) pathogenesis consists of its independent inflammatory response induction and mediated stimulation of proinflammatory factors synthesis resulting in joint destruction. The aim of study was to determine the role of IL-17 in immuno-inflammatory/autoimmune reactions development and to reveal IL-17 serum level associations with clinical and immunological characteristics of RA. Methods: 50 patients with early RA (disease duration >, Russia), anti-CCP antibodies (Axies-Shield Diagnostic, UK) were revealed using ELISA immunoassay. Results: On the base of IL-17 serum level patients were divided in two groups: group1 (n = 28) were patients with normal IL-17 serum level and group2 (n = 22) were those with high IL-17 serum level. In the group2, the rate of patients' pain assessment by visual analogue scale (67.3 ± 7.2 vs 32.8 ± 4.6; P < 0.001), tender (16.7 ± 2.0 vs 8.4 ± 1.1; P < 0.01) and swollen (12.3 ± 2.3 vs 3.9 ± 0.8; P < 0.01) joint count, DAS28 (5.0 ± 0.4 vs 2.8 ± 0.2 P < 0.01) were significantly higher compare to group1. It was found that in group2 the higher T-lymphocyte amount (CD3) was due to CD4 higher quantity, at the same time CD8 amount was significantly lower (22.2 ± 1.5% vs 28.4 ± 1.7%, P < 0.05) compare to group1. This caused the immunoregulative index increasing and indicated in the lost of autoimmune process regulation, including B-lymphocytes (CD19) activation. The CD154 expression was significantly lower in the group2 (3.4 ± 0.4% vs 10.8 ± 2.8%, P < 0.05) compare to group1. The difference in autoimmune reaction indices wasn't significant between groups except antibody-producing B-lymphocytes (13.7 ± 1.5% vs 8.5 ± 1.0%, P < 0.05) and IgM RF serum level (2.9 ± 0.3 U/ml vs 1.6 ± 0.5 U/ml, P < 0.05), which were significantly higher in group1. The IL-17 level had a positive correlative connections with DAS28 (r = 0.7; P < 0.05), circulative immune complex level (r = 0.38; P < 0.05), anti-CCP antibodies (r = 0.4; P < 0.05), IgM RF (r = 0.41; P < 0.05), CD4 (r = 0.38; P < 0.05) and negative correlative connection with CD8 (r = -0.39; P < 0.05). Conclusions: The importance of IL-17 value in immuno-inflammatory and autoimmune reactions development through T-lymphocytes activation in RA pathogenesis was confirmed. Thus the influence on T-depended immuno-inflammatory reaction products synthesis could be a new therapeutic target of RA patients' management. Disclosure statement: All authors have declared no conflicts of interes

In vivo imaging of matrix metalloprotease 12 and matrix metalloprotease 13 activities in the mouse model of collagen-induced arthritis

Objective: To develop enzyme-activatable Förster resonance energy transfer (FRET) substrate probes to detect matrix metalloproteinase 12 (MMP-12) and MMP-13 activities in vivo in mouse models of inflammatory arthritis. Methods: Peptidic FRET probes activated by MMP-12 and MMP-13 were reverse designed from inhibitors selected from a phosphinic peptide inhibitor library. Selectivity of the probes was demonstrated in vitro using MMP-1, MMP-2, MMP-3, MMP-12, and MMP-13. In vivo activation of the probes was tested in the zymosan-induced mouse model of inflammation, and probe specificity was evaluated by the MMP inhibitor GM6001 and specific synthetic inhibitors of MMP-12 and MMP-13. The probes were used to monitor these enzyme activities in the collagen-induced arthritis (CIA) model in vivo. Results: The MMP-12 and MMP-13 activity probes (MMP12ap and MMP13ap, respectively) discriminated between the activities of the 2 enzymes. The in vivo activation of these probes was inhibited by GM6001 and by their respective specific inhibitors. In the CIA model, MMP12ap activation peaked 5 days after disease onset and showed strong correlation with disease severity during this time (r = 0.85, P < 0.0001). MMP13ap activation increased gradually after disease onset and correlated with disease severity over a longer period of 15 days (r = 0.58, P < 0.0001). Conclusion: We generated two selective FRET probes that can be used to monitor MMP-12 and MMP-13 activities in live animals. MMP12ap follows the initial stage of inflammation in CIA, while MMP13ap follows the progression of the disease. The specificity of these probes is useful in monitoring the efficacy of MMP inhibitors. © 2014, American College of Rheumatology

BSR and BHPR guideline for the treatment of systemic sclerosis

Scope and purpose: SSc is a complex, multi-organ disease that requires a comprehensive multidisciplinary guideline. This is a short summary of the guideline, which is available in full as supplementary material at Rheumatology Online. Each recommendation is graded for level of evidence (I-IV) and strength (A-D). Eligibility and exclusion criteria: Patients are classified as having SSc based on current classification criteria (ACR/EULAR 2013 [1]). Other scleroderma spectrum diseases are not included in this document