This study explored the potential predictive utility of KL-6, RDW, NLR, SII, MLR, and PLR for identifying ILD in CTD patients and for assessing the severity of CTD-ILD, with the aim of providing accessible, cost-effective, and efficient biomarkers for clinical applications. It is well-established that KL-6 is associated with lung disease, promoting the fibrosis and anti-apoptotic effects on lung fibroblasts that lead to pulmonary fibrosis (Ahmed & Handa, 2022; Zuo et al., 2022).