The scientific focus of MIAMI - directed to achieving better diagnostic tools and novel targets for pharmaceutical therapies to significantly improve patient care in seronegative arthritis  - can be summarized into four main objectives:

Objective 1 - Mechanisms of initiation and progression of the disease

  • We will analyse of the expression of S100-DAMPs in arthritis and mucosal inflammation, using synovial fluid, articular and intestinal biopsy tissue (to be completed at month 24). Special attention will be given to compare their role in systemic immune activation (by analysing S100-DAMPs on human monocyte-macrophage functions) as opposed to their role at sites of inflammation (gut or/and joint compartments).
  • Investigation of S100-DAMPs as bystanders, amplifiers, or as disease-driving forces in cellular assays and mouse models of experimental arthritis and colitis (mouse models see WP1 and WP2). We will analyse the proinflammatory function of S100-DAMPs in arthritis and mucosal inflammation (to be completed at month 36).

Objective 2 - The potential of biomarkers for patient identification and stratification

  • DAMPs will be used as biomarkers for an early identification of patients (e.g. systemic JIA) or groups at special risk (e.g. mucosal or articular inflammation in relatives of patients with SpA, IBD, or Psoriasis), completed at month 36.
  • We will optimize the performance of different assays for S100A8/A9 and S100A12 regarding disease-specific cut-offs in the different forms of seronegative arthritis and bowel disease. In addition, and as a strong translational link to objective 1, we will develop a quantitative assay for murine S100A8/A9 and in this way will establish (in murine models of arthritis) the first reliable biomarker to monitor disease activity. 
  • For a major technical innovation, we will translate our findings from objective 1 into clinical application by addressingspecific targets (monomers of S100A8 and S100A9, complex forms, other S100-DAMPS); specific formats (semi-quantitative bedside tests, stool assays, blood, synovial fluid, imaging); or specific indications (screening of risk populations, detection of organ-involvement, prediction of response and outcome, confirmation of disease remission). Novel point-of-care tests will be developed and validated, e.g. lateral-flow immunoassays. This represents a ‘horizontal’ task (across WP’s), to analyse/validate the results from other objectives (to be completed at month 36).

Objective 3 - Identification of novel disease markers for monitoring activity

  • We will use a comprehensive and co-ordinated approach to identify promising new biomarkers (to be completed at month 24), using advanced protein expression profiling technology by label-free LC-MS/MS (proteomics), multiplex cytokine and chemokine assays (cytokinomics), and screening of micro-RNA profiles (transcriptomics). This will give us a unique and distinctive advantage of being able to integrate the results of different discovery (molecular profiling) strategies.
  • We will use samples from existing cohorts and biobanks to analyse the identified biomarker panels as tools to improve outcome measures in chronic joint and gut disease. After providing proof-of-principle, prospective clinical studies implementing stratified therapeutic approaches based upon biomarkers will be designed longitudinally (existing experience at UCMU and WWU for JIA, WWU for IBD, UGent for SpA, and UCD for PsA).
  • We will monitor therapy and search for subclinical inflammation in patients during disease remission. By defining clinically valuable cut-offs for definition of immunological remission we will provide therapy-stop-rules, with the aim of developing commercial assays (to be completed at month 36).

Objective 4 - Monitoring local disease activity and extension

  • Starting from preliminary data, molecular imaging using S100-DAMPs will first be established in animal models. We will image-track macrophages to inflamed joints in mouse models of seronegative arthritis or to the inflamed intestine in experimental colitis. We will combine imaging of S100-DAMPs with specific fluorescent antibodies and enzyme (metalloproteinases) activity using fluorescent probes and correlate that to joint destruction in seronegative arthritis (to be completed at month 36).
  • Comparison with data from humans will be analysed by also correlating to imaging results and immunohistochemical analyses in biopsy specimens (synovia, gut, skin). These studies will provide insights on how targets that can be detected by molecular imaging correlate to the site and extent of inflammation in vivo (to be completed at month 36).
  • To foster translational activities, we will develop new means to image inflammation by using existing small molecules binding to S100-DAMPs, which are approved for use in humans (to be completed at month 36).