Photo Credit: Md Babul Hosen
The following is a summary of “Serum KL-6 and SP-D: Markers of Lung Function in Autoimmune-Related Interstitial Lung Diseases,” published in the January 2025 issue of Pulmonology by Miądlikowska et al.
Researchers conducted a retrospective study to evaluate the utility of serum KL-6, SP-D, and TGF-β1 levels in assessing lung impairment and predicting short-term progression of interstitial lung disease (ILD) in patients with interstitial pneumonia with autoimmune features (IPAF).
They assessed 24 individuals with IPAF, 21 with connective tissue disease-associated ILD (CTD-ILD), and 23 with CTD without ILD for 1 year. Serum levels of KL-6, SP-D, and TGF-β1 were measured. The relationships between these markers and disease severity, as well as progression, were analysed.
The results showed that KL-6, SP-D, and TGF-β1 levels were significantly higher in patients with IPAF and CTD-ILD compared to those with CTD without ILD (P < 0.0001, P = 0.0005, and P = 0.0001, respectively), KL-6 (r = 0.45, P = 0.002) and SP-D (r = 0.35, P = 0.02) correlated with lung involvement in high-resolution computed tomography (HRCT) in the ILD group. In IPAF, KL-6 correlated with pulmonary function tests (forced vital capacity (FVC)%, transfer factor for carbon monoxide (TLCO)%, and 6-minute walk distance [6MWD]) and SpO2, while SP-D correlated with 6MWD and SpO2. In CTD-ILD, KL-6 and SP-D were positively correlated with bronchoalveolar lavage (BAL) cell count (KL-6: r = 0.58, P = 0.04; SP-D: r = 0.63, P = 0.02) and KL-6 also showed a negative correlation with time since symptom onset (r = −0.51, P = 0.02).
Investigators concluded that while KL-6 and SP-D might be useful biomarkers for assessing lung impairment in IPAF, no significant associations were found between baseline biomarker levels and ILD progression risk, leaving the predictive value for short-term prognosis uncertain.
Source: mdpi.com/1422-0067/26/3/1091