{
  "abstract": "Objective To investigate complement system activation and complement protein levels in relation to radiographic progression in axial spondyloarthritis (axSpA) within a longitudinal randomised controlled trial (RCT) of radiographic axSpA patients initiating tumour necrosis factor inhibitor (TNFi) therapy.Methods Serum samples from 96 patients with active radiographic axSpA in the multicentre RCT CONSUL were analysed by immunoassays for complement activation, that is, C3dg and complement proteins (MBL, CL-L1, M-, H- and L-ficolin; MASP-1,–2 and −3; and MAp44) before and after 108 weeks of TNF inhibitor therapy with golimumab.Results Baseline serum levels of total complement activation, that is, C3dg and lectin pathway activating protease MASP-1 were elevated in patients with new bone formation (new syndesmophytes and/or growth of existing syndesmophytes) after 2 years of follow-up, whereas baseline MASP-3 levels were decreased. Assessed by univariate logistic regression, baseline levels of MASP-1, MASP-3 and C3dg were associated with the development of new bone formation and remained significant in a corresponding multivariate logistic regression analysis. At follow-up, serum levels of C3dg and complement lectin pathway initiator L-ficolin were elevated in patients with new bone formation, and C3dg remained significant in a corresponding multivariate logistic regression analysis.Conclusions Complement activation marker C3dg, MASP-1 and MASP-3 levels before TNFi therapy predicted new bone formation after 2 years of follow-up among axSpA patients with a high risk of radiographic progression. Furthermore, levels of L-ficolin and C3dg at follow-up were elevated in axSpA patients with new bone formation. Our findings support an association between activation of the complement system and radiographic spinal progression in patients with axSpA.",
  "authors": [
    {
      "affiliations": [
        "Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark",
        "Department of Biomedicine, Aarhus University, Aarhus, Denmark",
        "Department of Clinical Medicine, Aarhus University, Aarhus, Denmark"
      ],
      "name": "Clara Mistegaard"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark",
        "Department of Biomedicine, Aarhus University, Aarhus, Denmark",
        "Department of Clinical Medicine, Aarhus University, Aarhus, Denmark"
      ],
      "name": "Anne Troldborg"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Murat Torgutalp"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark",
        "Department of Clinical Medicine, Aarhus University, Aarhus, Denmark"
      ],
      "name": "Anne Gitte Loft"
    },
    {
      "affiliations": [
        "Department of Biomedicine, Aarhus University, Aarhus, Denmark"
      ],
      "name": "Steffen Thiel"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany",
        "Department of Rheumatology CCM, Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Burkhard Muche"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Valeria Rios Rodriguez"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Mikhail Protopopov"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Joachim Listing"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Joachim Sieper"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Denis Poddubnyy"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology, and Rheumatology (including Nutrition Medicine), Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Fabian Proft"
    }
  ],
  "title": "Complement system activation is associated with spinal radiographic progression in axial spondyloarthritis after 2 years of follow-up: findings from the CONSUL RCT",
  "uid": "ae9f3f51-60b0-52fe-9e4c-42cd16709ea8"
}