Arthritis Research & Therapy (Aug 2021)

The role of lung ultrasound B-lines and serum KL-6 in the screening and follow-up of rheumatoid arthritis patients for an identification of interstitial lung disease: review of the literature, proposal for a preliminary algorithm, and clinical application to cases

  • Yukai Wang,
  • Shaoqi Chen,
  • Shaoyu Zheng,
  • Jianqun Lin,
  • Shijian Hu,
  • Jinghua Zhuang,
  • Qisheng Lin,
  • Xuezhen Xie,
  • Kedi Zheng,
  • Weijin Zhang,
  • Guangzhou Du,
  • Guohong Zhang,
  • Anna-Maria Hoffmann-Vold,
  • Marco Matucci-Cerinic,
  • Daniel E. Furst

DOI
https://doi.org/10.1186/s13075-021-02586-9
Journal volume & issue
Vol. 23, no. 1
pp. 1 – 10

Abstract

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Abstract Screening and follow-up of interstitial lung disease associated with rheumatoid arthritis (RA-ILD) is a challenge in clinical practice. In fact, the majority of RA-ILD patients are asymptomatic and optimal tools for early screening and regular follow-up are lacking. Furthermore, some patients may remain oligosymptomatic despite significant radiological abnormalities. In RA-ILD, usual interstitial pneumonia (UIP) is the most frequent radiological and pathological pattern, associated with a poor prognosis and a high risk to develop acute exacerbations and infections. If RA-ILD can be identified early, there may be an opportunity for an early treatment and close follow-up that might delay ILD progression and improve the long-term outcome. In connective tissue disease–associated interstitial lung disease (CTD-ILD), lung ultrasound (LUS) with the assessment of B-lines and serum Krebs von den Lungen-6 antigen (KL-6) has been recognized as sensitive biomarkers for the early detection of ILD. B-line number and serum KL-6 level were found to correlate with high-resolution computed tomography (HRCT), pulmonary function tests (PFTs), and other clinical parameters in systemic sclerosis–associated ILD (SSc-ILD). Recently, the significant correlation between B-lines and KL-6, two non-ionizing and non-invasive biomarkers, was demonstrated. Hence, the combined use of LUS and KL-6 to screen and follow up ILD in RA patients might be useful in clinical practice in addition to existing tools. Herein, we review relevant literature to support this concept, propose a preliminary screening algorithm, and present 2 cases where the algorithm was used.

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