{
  "abstract": "Introduction Interstitial lung disease (ILD) is a leading cause of morbidity and mortality in systemic sclerosis (SSc). Early detection and continuous monitoring of ILD are critical for timely intervention and improved clinical outcomes. In recent years, serum biomarkers have gained recognition as potential non-invasive tools for evaluating ILD onset, progression, and prognosis. However, their clinical utility in SSc-ILD remains incompletely understood. This study aimed to evaluate the prognostic value of serum biomarkers—KL-6, IL-18, and IL-18 binding protein (IL-18BP)—for assessing ILD progression and mortality in SSc patients.Material and Methods This prospective cohort study followed 74 SSc patients for 24 months. Patients were stratified based on the presence or absence of ILD using high-resolution computed tomography (HRCT). Clinical assessments, pulmonary function tests (PFTs), and serum biomarker levels (KL-6, IL-18, and IL-18BP) were measured. ILD progression was defined by changes in forced vital capacity (FVC). Relationships between biomarkers, lung function, and ILD severity were analyzed using Pearson’s correlation. Receiver operating characteristic (ROC) curves determined optimal biomarker thresholds, while logistic regression identified predictors of ILD progression and mortality, accounting for potential confounders.Results Among the 74 patients, 38% had ILD at baseline, increasing to 54% over two years. The proportion of patients with lung involvement equal or more than 20% rose from 32% to 43%. Serum KL-6 emerged as a robust biomarker, with an annual increase of +14.18 identified as the threshold for progressive ILD (AUC: 0.803, P = 0.002, sensitivity: 80%, specificity: 64%). For mortality, an annual increase of +71.17 in KL-6 showed the highest predictive accuracy (AUC: 0.91, 95% CI: 0.84–0.99, P < 0.0001, sensitivity: 75%, specificity: 85%). DLCO was also predictive of mortality, with a -17% annual decrease identified as a key threshold (AUC: 0.20, P = 0.006). Changes in IL-18, IL-18BP, ESR, and CRP exhibited limited predictive utility. Logistic regression identified changes in KL-6, DLCO, CRP, and anti-Scl70 antibodies as independent predictors of progressive ILD. Multivariate analysis confirmed that immunosuppressive therapy was protective against ILD progression (OR: 0.27, 95% CI: 0.16–0.92, P = 0.004).Conclusions Serum KL-6 is a reliable biomarker for predicting ILD progression and mortality in systemic sclerosis, with well-defined thresholds showing high sensitivity and specificity. Changes in DLCO and anti-Scl70 antibodies were also independent predictors of ILD progression, while immunosuppressive therapy demonstrated a protective effect. These findings highlight the potential of KL-6 for non-invasive monitoring and risk stratification in SSc-ILD.Abstract P.086 Figure 1",
  "authors": [
    {
      "affiliations": [
        "University of Manchester, Manchester, United Kingdom"
      ],
      "name": "Cristiana Sieiro Santos"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Miriam Retuerto Guerrero"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Jose Ordas Martinez"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Sara Calleja Antolin"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Juan Garcia Herrero"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Laura Sierra Herranz"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Javier De La Calle Lorenzo"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Elena Bollo De Miguel"
    },
    {
      "affiliations": [
        "Hospital de Santa Maria & Instituto de Medicina Molecular - Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal"
      ],
      "name": "Goncalo Boleto"
    },
    {
      "affiliations": [
        "Hospital de Santa Maria & Instituto de Medicina Molecular - Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal"
      ],
      "name": "Vasco Romao"
    },
    {
      "affiliations": [
        "Complejo Asistencial Universitario de Leon, Leon, Spain"
      ],
      "name": "Elvira Diez Alvarez"
    }
  ],
  "title": "P.086 Serum KL-6 as a predictive biomarker for interstitial lung disease progression and mortality in systemic sclerosis: a prospective cohort study",
  "uid": "066a330d-f969-5818-bafd-de0bba741803"
}