{
  "abstract": "Introduction Antimitochondrial antibodies (AMA), the hallmark of primary biliary cholangitis (PBC), have been inconsistently reported and poorly characterized in systemic sclerosis (SSc). AMA mainly target E2-pyruvate dehydrogenase complex (E2-PDC).Material and Methods A retrospective cross-sectional study was conducted on consecutive SSc patients followed at our referral center. According to reference standards ( www.anapatterns.org), HEp-2 indirect immunofluorescence was performed as screening for autoantibodies to nuclear and cytoplasmic antigens; then, for sera displaying a suggestive pattern (cytoplasmic reticular/AMA-like), anti-E2-PDC were confirmed by ELISA. Demographic and clinical features were compared between AMA-positive (anti-E2-PDC+) and negative (no suggestive immunofluorescence or negative anti-E2-PDC) cases.Demographic and clinical variables were collected, including skin, vascular, lung, myocardial, and gastrointestinal (GI) involvement (clinically-defined). Data of GI endoscopy were also collected; endoscopy was performed in case of positive fecal occult blood, screening of GI neoplasm, iron-deficiency anemia, unexplained weight loss, persistent epigastric/abdominal pain, early satiety, dyspepsia, bowel habit changes. Gastric antral vascular ectasia (GAVE) and GI telangiectasias were recorded, the term ‘GI vascular involvement’ encompassing both conditions.Results Among 165 SSc patients (20% diffuse disease, 33% interstitial lung disease, 7.3% pulmonary arterial hypertension; 51% with anticentromere antibodies, 29% anti-topoisomerase I, 12% anti-RNA polymerase III), 41 (25%) had the AMA-like pattern on HEp-2 immunofluorescence and 37 (22%) were finally AMA-positive (anti-E2-PDC+).AMA were more frequent in patients with PBC (41% vs. 1.6%; p<0.001) and ACA (76% vs. 44%; p=0.001), but not linked to differences in cutaneous, vascular, pulmonary, or myocardial involvement. Clinically defined SSc-GI involvement did not differ between AMA-positive and negative patients.Overall, endoscopic evaluation (available in 113 patients) revealed GI vascular involvement in 12 subjects (11% of those undergoing endoscopies, 7.3% of total cohort), including 5 cases of GAVE (4.4% and 3.0%, respectively). AMA positivity was independently associated with GI vascular involvement (OR 13.3, 95% CI 2.53-95.0; p=0.002) and more specifically with GAVE (OR 7.99, 95% CI 1.05-72.5; p=0.045). These associations were independent from demographic features (age, sex, disease duration), PBC overlap, co-existence of ACA or anti-RNA polymerase III (a notable risk factor for GAVE).Conclusions Systematic screening revealed AMA in 22% SSc patients. We confirm the association of AMA with PBC and ACA, and suggest a novel association with GI vascular involvement in SSc warranting confirmation in independent cohorts. Remarkably, a minority of SSc patients has autoantibodies targeting mitochondrial antigens distinct from E2-PDC, highlighting the importance of HEp-2 immunofluorescence and needing characterization.",
  "authors": [
    {
      "affiliations": [
        "Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy",
        "Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, Rozzano, Italy"
      ],
      "name": "Antonio Tonutti"
    },
    {
      "affiliations": [
        "Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy",
        "Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, Rozzano, Italy"
      ],
      "name": "Francesca Motta"
    },
    {
      "affiliations": [
        "Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, Rozzano, Italy"
      ],
      "name": "Natasa Isailovic"
    },
    {
      "affiliations": [
        "Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy",
        "Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, Rozzano, Italy"
      ],
      "name": "Carlo Selmi"
    },
    {
      "affiliations": [
        "Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy",
        "Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, Rozzano, Italy"
      ],
      "name": "Angela Ceribelli"
    },
    {
      "affiliations": [
        "Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy",
        "Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, Rozzano, Italy"
      ],
      "name": "Maria De Santis"
    }
  ],
  "title": "P.166 High prevalence of antimitochondrial antibodies and association with gastrointestinal vascular involvement in systemic sclerosis",
  "uid": "ae14cf67-b018-5923-bf9d-81064d7eff0b"
}