{
  "abstract": "Objective To determine whether clinically inactive/low-activity SLE reflects immunological remission in this cross-sectional study using CD180 (RP105)-anchored, stage-resolved profiling of peripheral B-cell differentiation.Methods CD19 + B cells were analysed by flow cytometry in healthy controls (HCs; n=27), active SLE (n=29; sampled on admission before treatment initiation/escalation) and inactive/low-activity SLE (n=14; biological-free; ≥5 years of sustained Lupus Low Disease Activity State and/or Definition of Remission in SLE remission). Six ordered stages (subsets 0–5) were defined along the CD180-loss trajectory. CXCR5, CD11c, B-cell activating factor receptor and B-cell maturation antigen (BCMA) were quantified. Non-parametric tests with Benjamini-Hochberg false discovery rate (FDR) adjustment were applied.Results Active SLE redistributed towards downstream CD180 − plasmablast-lineage stages (subsets 2–5) (14.07% vs 1.92% in HCs). Inactive/low-activity SLE retained a residual plasmablast-lineage (subset 2–5: 6.17%) expansion above HC levels despite durable quiescence. In HCs, CXCR5 positivity was high in upstream CD180+ compartments and declined stepwise across the trajectory. CXCR5 positivity at subset 0 was reduced in active SLE (FDR-adjusted p=0.0273) and inactive/low-activity SLE (FDR-adjusted p=0.0015) and at subset 3 in active SLE (FDR-adjusted p=0.0273) versus HCs. CD11c was enriched in upstream compartments during active disease, whereas BCMA was increased in mature downstream CD180− stages.Conclusions CD180-anchored, stage-resolved profiling indicates that clinical quiescence may not fully equate to immunological normalisation in SLE. These cross-sectional observations do not establish durable persistence, and longitudinal validation is needed. An upstream CXCR5 decrement detectable even in long-term quiescence is consistent with extrafollicular-leaning priming changes arising before CD180 loss; however, any implications for longitudinal immunomonitoring remain hypothesis-generating.",
  "authors": [
    {
      "affiliations": [
        "Department of Medical Technology and Sciences, International University of Health and Welfare, Okawa, Japan"
      ],
      "name": "Ayana Kanagawa"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Faculty of Medicine, Saga University, Saga, Japan"
      ],
      "name": "Akihito Maruyama"
    },
    {
      "affiliations": [
        "Department of Medical Technology and Sciences, International University of Health and Welfare - Fukuoka Campus, Okawa, Japan"
      ],
      "name": "Tatsuki Shibuta"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Faculty of Medicine, Saga University, Saga, Japan"
      ],
      "name": "Mitsuteru Akahoshi"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Takagi Hospital, Okawa, Japan"
      ],
      "name": "Sachiko Soejima"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Takagi Hospital, Okawa, Japan",
        "Department of Rheumatology, Faculty of Medicine, International University of Health and Welfare, Okawa, Japan"
      ],
      "name": "Yoshifumi Tada"
    },
    {
      "affiliations": [
        "Department of Medical Technology and Sciences, International University of Health and Welfare, Okawa, Japan"
      ],
      "name": "Syuichi Koarada"
    }
  ],
  "title": "Stage-resolved mapping of RP105 (CD180)-negative B cells reveals residual plasmablast-lineage skewing in SLE: a cross-sectional study",
  "uid": "86bc12c0-1b3c-5f06-af63-7354ec727b78"
}