{
  "abstract": "Objectives Introduction Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease driven by multiple immunopathogenic pathways, including B-cell activation and type I interferon signalling. Despite therapeutic advances, many patients remain refractory to conventional immunosuppression or B-cell–targeted therapies, emphasizing the need for pathway-specific approaches.Methods Case Report A 30-year-old woman was diagnosed with SLE in 2014 (age 19) after presenting with malar rash, oral ulcers, and inflammatory arthralgias. Laboratory tests revealed ANA 1:1280 (homogeneous pattern), anti-dsDNA positivity, and hypocomplementemia, fulfilling both the SLICC 2012 and EULAR/ACR 2019 SLE classification criteria. She initiated treatment with methotrexate, hydroxychloroquine, and prednisolone. In 2015, she developed class IV diffuse proliferative lupus nephritis with nephrotic-range proteinuria and microscopic hematuria. Adequate renal response was achieved after induction therapy with mycophenolate 3 g/day and methylprednisolone pulses, followed by prednisolone 1 mg/kg/day. Maintenance therapy with mycophenolate 1.5 g/day, hydroxychloroquine, and moderate-low dose corticosteroids allowed sustained remission for several years.In 2021, she had a new flair with renal, mucocutaneous, and articular involvement; renal biopsy confirmed recurrent class IV nephritis. High-dose corticosteroids and mycophenolate 3 g/day led only to partial response (SLEDAI-2K = 10). In 2022, belimumab 200 mg weekly was added, resulting in renal remission but persistent articular, mucocutaneous, hematologic (lymphopenia), and serologic activity (SLEDAI-2K 6–8 on prednisolone 10 mg/day).Results In August 2024, anifrolumab 300 mg IV monthly was introduced. After six months, the SLEDAI-2K decreased to 2, with residual serologic activity only, and at one-year mark she remained clinically quiescent with stable renal function on low-dose prednisolone.Conclusions This case illustrates the complexity of refractory SLE and the value of mechanistically guided therapy. While belimumab controlled renal disease, interferon-driven inflammation persisted. Subsequent IFNAR1 blockade with anifrolumab effectively addressed both renal and extra-renal manifestations. Targeting the interferon pathway represents a safe and effective strategy for patients with SLE refractory to B-cell blockade.",
  "authors": [
    {
      "affiliations": [
        "Unidade Local de Santa Maria Department of Rheumatology, Lisbon, Portugal"
      ],
      "name": "Miguel Martins"
    },
    {
      "affiliations": [
        "Unidade Local de Santa Maria Department of Rheumatology, Lisbon, Portugal",
        "Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal"
      ],
      "name": "Sofia Barreira"
    },
    {
      "affiliations": [
        "Unidade Local de Santa Maria Department of Rheumatology, Lisbon, Portugal"
      ],
      "name": "Carla Macieira"
    }
  ],
  "title": "PO:04:108 From B-cell blockade to interferon inhibition: achieving remission in refractory systemic lupus erythematosus",
  "uid": "819a7dea-dff7-5120-a11a-3499b50a8770"
}