{
  "abstract": "Objectives To assess the clinical and imaging characteristics associated with fibroblast activation detected by 68Gallium-labelled fibroblast activation protein inhibitor positron emission tomography/CT (68Ga-FAPI-PET/CT) in patients with psoriasis and whether 68Ga-FAPI uptake correlates with the risk of progression to psoriatic arthritis (PsA).Methods Psoriasis patients with arthralgia underwent 68Ga-FAPI-PET/CT and were followed up prospectively. 68Ga-FAPI uptake was assessed at 71 articular sites and patients with ≥1 joint with 68Ga-FAPI uptake and PET/CT Joint Index≥2 were considered FAPI positive. The associations between FAPI uptake and clinical and ultrasound (US) findings were investigated. Survival analyses were conducted to assess the association between 68Ga-FAPI uptake and progression to PsA.Results 45 patients with psoriasis were enrolled, 37 of whom (82%) were FAPI positive. FAPI-positive psoriasis patients had significantly higher body mass index (BMI) (p=0.036) and Disease Activity Score 28-C reactive protein (p=0.033) compared with FAPI-negative patients. 68Ga-FAPI uptake was most frequent in large joints and mechanically stressed sites and was more likely in the presence of low-grade synovial hyperplasia (OR: 1.77, 95% CI 1.08 to 2.89), entheseal Power Doppler (OR: 3.80, 95% CI 1.66 to 8.72) and concomitant osteoarthritis (OA). FAPI-positive patients showed a higher risk of progression to PsA compared with FAPI-negative patients (HR 7.1, 95% CI 0.9 to 53.6) (log-rank p=0.028). Only 1/8 patients with psoriasis (12.5%) without 68Ga-FAPI uptake developed PsA, as opposed to 18/37 (49%) of FAPI-positive patients.Conclusions In psoriasis patients with arthralgia, 68Ga-FAPI uptake, indicating fibroblast activation, is associated with higher BMI, more pain, subclinical US changes and concomitant OA. Pathological 68Ga-FAPI uptake at articular sites was indicative of higher risk of progression to PsA in our cohort, suggesting fibroblast activation as a crucial step to develop PsA.",
  "authors": [
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Giulia Corte"
    },
    {
      "affiliations": [
        "Department of Nuclear Medicine, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Armin Atzinger"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Serviço de Medicina Interna, Hospital Pedro Hispano, Unidade Local de Saúde de Matosinhos, Matosinhos, Portugal"
      ],
      "name": "Rita Noversa de Sousa"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Melek Yalcin Mutlu"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Alp Temiz"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Sara Bayat"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Maria Gabriella Raimondo"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Andreas Ramming"
    },
    {
      "affiliations": [
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Department of Dermatology, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Michael Sticherling"
    },
    {
      "affiliations": [
        "Department of Nuclear Medicine, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Institute for Medical Engineering, Technical University of Applied Sciences Amberg– Weiden, Weiden, Germany"
      ],
      "name": "Christian Schmidkonz"
    },
    {
      "affiliations": [
        "Department of Nuclear Medicine, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Torsten Kuwert"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Georg Schett"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Koray Tascilar"
    },
    {
      "affiliations": [
        "Department of Internal Medicine 3, Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany",
        "Deutsches Zentrum Immuntherapie (DZI), Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany"
      ],
      "name": "Filippo Fagni"
    }
  ],
  "title": "Increased synovial and entheseal fibroblast activation detected by 68Ga-FAPI-PET/CT is associated with the development of psoriatic arthritis in psoriasis patients with arthralgia",
  "uid": "7a491335-a8f9-5b7f-bd62-9a8d3be93ee7"
}