{
  "abstract": "Objectives As systemic lupus erythematosus(SLE) is an autoimmune disease characterised by the formation of autoantibodies, diagnostic immunology laboratory tests for detecting and quantifying autoantibodies are used for the diagnosis of SLE. These include antinuclear antibodies, anti-dsDNA and anti-Sm, together with other antibodies such as antiphospholipid(aPL) or complement proteins C3andC4. By contrast, although antibodies that recognize RNA-binding proteins are also common in patients with SLE, they are not part of the classification criteria and have a wider distribution among diseases. The aim of the study was to determine the frequency of different spectrum of antibodies in patients with SLE from the Russian cohortMethods This observational retrospective-prospective study included 140patients (88% women, median aged 34[26;41]years (median [interquartile range 25;75%]), with SLE(SLICC 2012). Baseline demographics, disease characteristic, organ system involvement/damage were analysed descriptively according to SLEDAI-2k, Systemic Lupus International Collaborating Clinics damage index(SDI).Results The median disease duration was 3,4 [0,4;12,0]years, SLEDAI-2k at the time of inclusion–6,5 [4,0;10,5]score, SDI–0 [0;2]score.At the time of inclusion, the main clinical manifestations of SLE were: hematological disorders-46%, cutaneous lupus-34%, inflammatory arthritis-33%, lupus nephritis-29%, non-scarring alopecia-23%, serositis-17%, mucosal ulcers-7%, nervous system involvement-7%. Among ‘non-criteria’ symptoms the most common were: livedo-24%, Raynaud’s phenomenon-14%, interstitial lung diseases-10%, lymphadenopathy-7%, ulcerative necrotising vasculitis-3%, myocarditis-1%. Concomitant antiphospholipid syndrome(APS) and Sjögren’s syndrome(SS) were detected in 11% and 36% of patients, respectively.Hypocomplementemia for C3 and/or C4 was detected in 64% of patients, the most common autoantibodies were positive anti-dsDNA-69%, anti-C1q -43%, anti-Ro/SSA-39% and aPL-30%, the rarest were positive anti-La/SSB-9%, anti-RNP-70 -10%, anti-Sm-11% and rheumatoid factor(RF) -14%.In patients with SLE, when SS was excluded, the frequency of diagnostic antibodies for SS decreased: RF from 14% to11%, anti-Ro/SSA from 39% to22%, anti-La/SSB from 9% to1%.When APS was excluded, the frequency aPL decreased from 30% to14%Conclusions Hypocomplementemia is as common as positive anti-dsDNA in most SLE cases. Second most common is positive anti-C1q, which is not included in either the 2012 or 2019 SLE classification criteria or the SLE activity indices. Third most common is positive anti-Ro/SSA, even when excluding SS. Other autoantibodies:anti-La/SSB, anti-RNP-70, RF, aPL(without APS) are rare, occurring in no more than 1-14%.",
  "authors": [
    {
      "affiliations": [
        "V.A.Nasonova Research Institute of Rheumatology, Moscow, Russia"
      ],
      "name": "Tatiana Panafidina"
    },
    {
      "affiliations": [
        "V.A.Nasonova Research Institute of Rheumatology, Moscow, Russia"
      ],
      "name": "Tatiana Popkova"
    },
    {
      "affiliations": [
        "V.A.Nasonova Research Institute of Rheumatology, Moscow, Russia"
      ],
      "name": "Anastasiia Shumilova"
    },
    {
      "affiliations": [
        "V.A.Nasonova Research Institute of Rheumatology, Moscow, Russia"
      ],
      "name": "Yulia Gorbunova"
    },
    {
      "affiliations": [
        "V.A.Nasonova Research Institute of Rheumatology, Moscow, Russia"
      ],
      "name": "Liubov Kondrateva"
    },
    {
      "affiliations": [
        "V.A.Nasonova Research Institute of Rheumatology, Moscow, Russia"
      ],
      "name": "Anastasia Avdeeva"
    },
    {
      "affiliations": [
        "V.A.Nasonova Research Institute of Rheumatology, Moscow, Russia"
      ],
      "name": "Alexander Lila"
    }
  ],
  "title": "PO:02:041 The frequency of different spectrum of antibodies and complement C3/C4 in patients with systemic lupus erythematosus",
  "uid": "35ff3afd-54b5-5934-960f-89812264292c"
}