Journal of Inflammation Research (Apr 2022)

KL-6 as a Biomarker of Interstitial Lung Disease Development in Patients with Sjögren Syndrome: A Retrospective Case–Control Study

  • Chiu YH,
  • Chu CC,
  • Lu CC,
  • Liu FC,
  • Tang SE,
  • Chu SJ,
  • Kuo SY,
  • Chen HC

Journal volume & issue
Vol. Volume 15
pp. 2255 – 2262

Abstract

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Yu-Hsiang Chiu,1,2 Chen-Chih Chu,1 Chun-Chi Lu,1 Feng-Cheng Liu,1 Shin-En Tang,3 Shi-Jye Chu,1 San-Yuan Kuo,1 Hsiang-Cheng Chen1 1Division of Rheumatology/Immunology/Allergies, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; 2Department of Rheumatology and Clinical Immunology, University Medical Centre Utrecht, Utrecht, the Netherlands; 3Division of Thoracic Medicine, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, TaiwanCorrespondence: Hsiang-Cheng Chen, Division of Rheumatology/Immunology/Allergy, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec, 2, Cheng-Gong Road, Neihu 114, Taipei, Taiwan, R.O.C, Tel +886 2 87927135, Fax +886 2 87927136, Email [email protected]: Krebs von den Lungen-6 (KL-6) is expressed on regenerating type II pneumocytes and has been recognized as biomarkers in interstitial lung disease (ILD). We aim to identify the role of the serum KL-6 level in patients with newly diagnosed Sjögren syndrome (SS), as well as the correlation between the immunoassays.Methods: Patients with newly diagnosed SS and receiving HRCT for clinical reason during follow-up were included. Baseline KL-6 level was measured via enzyme-linked immunosorbent assay (ELISA) and latex particle-enhanced turbidimetric immunoassay (LETIA).Results: Of the 39 patients, 21 (53.85%) developed interstitial lung disease (ILD) by the conclusion of the follow-up period. The median time to diagnosis of ILD was 2.24 years (IQR 1.15– 4.34) in the ILD group. The median serum KL-6 level, measured using ELISA, was 1232 U/mL (IQR 937– 2242) and 764.5 U/mL (IQR 503.25– 1035.75) in the ILD group and the non-ILD group, respectively (p = 0.001). The median LETIA for serum KL-6 was 329 U/mL (IQR 235– 619) and 245 U/mL (IQR 215.25– 291) in the ILD group and the non-ILD group, respectively (p = 0.074).Conclusion: Serum KL-6 levels were higher in newly diagnosed SS patients with ILD diagnosis during follow-up. Thus, the serum KL-6 level can serve as a valuable biomarker to identify hidden ILD in patients with newly diagnosed SS patients. However, the immunoassay procedure may influence the efficacy of the prediction and its clinical association.Keywords: Sjögren syndrome, interstitial lung disease, KL-6

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