{
  "abstract": "Background and Aims. Interpretation of isolated lupus anticoagulant (LAC) positivity remains challenging because LAC represents a functional coagulation abnormality rather than an antigen-defined immune response. Anti-phosphatidylserine/prothrombin (aPS/PT) antibodies have been proposed as non-criteria antiphospholipid antibodies that may refine serological characterization of LAC-positive patients. The study aims to determine whether aPS/PT antibodies identify antigen-defined subgroups associated with thrombotic phenotype among consecutive patients undergoing antiphospholipid antibody testing. Methods. We performed a retrospective two-center observational study including 131 consecutive adult patients referred for antiphospholipid antibody evaluation (Fig. 1). All underwent testing for LAC, anticardiolipin antibodies, anti-β2-glycoprotein I antibodies, and aPS/PT antibodies. Because antibody testing was performed after clinical events, thrombosis was analyzed as a historical clinical phenotype. Associations were assessed using stratified comparisons and logistic regression adjusted for age, sex, smoking status, and hypertension. Results. A history of objectively confirmed thrombosis was present in 72.1% of patients. aPS/PT IgM levels correlated with LAC activity measured by the dRVVT ratio. Patients positive for LAC and aPS/PT IgM but negative for anticardiolipin and anti-β2-glycoprotein I antibodies had significantly higher odds of prior thrombosis compared with the reference serological profile (adjusted OR 11.2; 95% CI 2.5–50.8; p = 0.002). Conclusions. In this selected tertiary referral cohort enriched for thrombotic disease, aPS/PT IgM identified a biologically and clinically distinct subset within LAC-positive patients associated with prior thrombosis. These findings support further prospective evaluation of aPS/PT testing for refinement of heterogeneous LAC positivity.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "name": "Raimondo De Cristofaro"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/08b7htygakcg7.bib",
  "cited_by": 0,
  "doi": null,
  "fulltext_url": "https://www.btvb.org/btvb/article/view/816",
  "id": "08b7htygakcg7",
  "issns": [
    "2785-5309"
  ],
  "landing_url": "https://www.btvb.org/btvb/article/view/816",
  "language": "en",
  "licence": "CC-BY-NC",
  "licence_label": "CC BY-NC",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "lcc",
      "RC666-701"
    ]
  ],
  "openalex": null,
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": "PAGEPress Publications",
  "ris": "https://research.draconitic.com/paper/08b7htygakcg7.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T13:47:29Z",
      "native_id": "5afb3ba777324c058e4d2ade2ffbbdb6",
      "source": "doaj",
      "url": "https://www.btvb.org/btvb/article/view/816"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "lcc:RC666-701",
      "subfield": "cardiovascular"
    }
  ],
  "title": "CO114 | ANTI-PS/PT IgM IDENTIFIES AN ANTIGEN-DEFINED SUBSET WITHIN LUPUS ANTICOAGULANT POSITIVITY ASSOCIATED WITH THROMBOTIC PHENOTYPE",
  "title_text": "CO114 | ANTI-PS/PT IgM IDENTIFIES AN ANTIGEN-DEFINED SUBSET WITHIN LUPUS ANTICOAGULANT POSITIVITY ASSOCIATED WITH THROMBOTIC PHENOTYPE",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T13:47:29Z",
  "url": "https://research.draconitic.com/paper/08b7htygakcg7",
  "venue": "Bleeding, Thrombosis and Vascular Biology",
  "versions": []
}