{
  "abstract": "Objective To investigate the prevalence of difficult-to-treat psoriatic arthritis (D2T-PsA) and classify patients with persistent inflammatory PsA (PIPsA) and non-inflammatory PsA (NIPsA) based on a combination of clinical and musculoskeletal ultrasound (MSUS) evidence of inflammation.Methods A multicentre cross-sectional study was conducted on PsA patients treated with biological disease-modifying anti-rheumatic drugs/targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs). D2T-PsA status was characterised by an inadequate response to ≥2 classes of b/tsDMARDs and the persistence of active disease, defined as a DAPSA >14.Results Out of 517 PsA patients on b/tsDMARDs, 53 (10.3%) met the criteria for D2T-PsA with 30 (57%) classified as PIPsA and 23 (43%) classified as NIPsA. The PIPsA phenotype had higher swollen joint count (2.5 (IQR 1.0–7.0) vs 0.0 (IQR 0.0–1.0), p<0.001), dactylitis (20% vs 0%, p=0.030) and nail psoriasis (40% vs 13%, p=0.027). Conversely, NIPsA patients had significantly greater ΔPtGA–PhGA (4.0 (IQR 2.5–5.0) vs 0.0 (IQR 0.0–1.5), p<0.001), higher tender points (16.0 (IQR 0.0–18.0) vs 0.0 (IQR 0.0–8.0), p=0.009), a higher SPARCC enthesitis index (5.0 (IQR 2.0–8.0) vs 2.0 (IQR 0.0–5.0), p=0.023). The MSUS showed higher ultrasound activity (3.81±2.0 vs 0.91±0.5, p<0.001) and greater structural damage (4.12±1.0 vs 2.38±2.1, p<0.001), with both activity and damage scores being higher in PIPsA patients.Conclusion The classification into PIPsA and NIPsA based on easily detectable clinical features can support a tailored therapeutic management of patients with D2T-PsA.",
  "authors": [
    {
      "affiliations": [
        "Department of Medicine (DMED), Rheumatology Division, University of Udine, University Hospital Santa Maria della Misericordia, Udine, Italy",
        "NIHR Leeds Musculoskeletal Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust and Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Chapel Allerton Hospital, Leeds, UK"
      ],
      "name": "Alen Zabotti"
    },
    {
      "affiliations": [
        "Department of Medicine (DMED), Rheumatology Division, University of Udine, University Hospital Santa Maria della Misericordia, Udine, Italy"
      ],
      "name": "Nicola Cabas"
    },
    {
      "affiliations": [
        "Epidemiology Unit, Italian Society for Rheumatology (SIR), Milano, Italy"
      ],
      "name": "Cristina Di Nicola"
    },
    {
      "affiliations": [
        "Academic Rheumatology Unit, Dipartimento di Medicina e Scienze della Salute \"Vincenzo Tiberio\", Università degli Studi del Molise, Campobasso, Italy"
      ],
      "name": "Fabio Massimo Perrotta"
    },
    {
      "affiliations": [
        "Department of Medicine (DMED), Rheumatology Division, University of Udine, University Hospital Santa Maria della Misericordia, Udine, Italy"
      ],
      "name": "Andrea Guiotto"
    },
    {
      "affiliations": [
        "Presidio Ospedaliero \"S. Antonio”, San Daniele del Friuli, Italy"
      ],
      "name": "Nicoletta Franzolini"
    },
    {
      "affiliations": [
        "Department of Medicine (DMED), Rheumatology Division, University of Udine, University Hospital Santa Maria della Misericordia, Udine, Italy"
      ],
      "name": "Ivan Giovannini"
    },
    {
      "affiliations": [
        "Institute of Statistics, Department of Medicine (DMED), University of Udine, Udine, Italy"
      ],
      "name": "Maria De Martino"
    },
    {
      "affiliations": [
        "Institute of Statistics, Department of Medicine (DMED), University of Udine, Udine, Italy"
      ],
      "name": "Miriam Isola"
    },
    {
      "affiliations": [
        "NIHR Leeds Musculoskeletal Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust and Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Chapel Allerton Hospital, Leeds, UK"
      ],
      "name": "Andrea Di Matteo"
    },
    {
      "affiliations": [
        "NIHR Leeds Musculoskeletal Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust and Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Chapel Allerton Hospital, Leeds, UK"
      ],
      "name": "Gabriele De Marco"
    },
    {
      "affiliations": [
        "NIHR Leeds Musculoskeletal Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust and Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Chapel Allerton Hospital, Leeds, UK"
      ],
      "name": "Dennis McGonagle"
    },
    {
      "affiliations": [
        "Academic Rheumatology Unit, Dipartimento di Medicina e Scienze della Salute \"Vincenzo Tiberio\", Università degli Studi del Molise, Campobasso, Italy"
      ],
      "name": "Ennio Lubrano"
    },
    {
      "affiliations": [
        "Department of Medicine (DMED), Rheumatology Division, University of Udine, University Hospital Santa Maria della Misericordia, Udine, Italy"
      ],
      "name": "Luca Quartuccio"
    }
  ],
  "title": "Using ultrasound to define inflammatory and non-inflammatory phenotypes in difficult-to-treat psoriatic arthritis",
  "uid": "bf515179-ff04-50ba-8ef9-8543f5b46c11"
}