Lung ultrasound B-lines and serum KL-6 in the management of connective tissue disease-associated interstitial lung disease

Background and objectives: Interstitial lung disease (ILD) is a major cause of morbidity and mortality in patients with connective tissue diseases (CTDs). Early diagnosis, appropriate intervention, and close monitoring are critical to mitigate the progression of CTD-ILD. Lung ultrasound (LUS) B-lines and serum Krebs von den Lungen-6 (KL-6) have emerged as promising, non-invasive, and radiation-free biomarkers for ILD. This single-center retrospective study aimed to evaluate the combined diagnostic and assessment value of B-lines and KL-6 in patients with CTD-ILD.