Serial change of KL-6 and development of PD-1/PD-L1 inhibitor-related pneumonitis in non-small cell lung cancer

초록

Background: Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective in the treatment of non-small cell lung cancer (NSCLC) but may occasionally cause serious pneumonitis in patients with NSCLC. Aims and objectives: To investigate the role of Krebs von den Lungen-6 (KL-6) in the prediction and diagnosis of PD-1/PD-L1 inhibitors-related pneumonitis in NSCLC. Methods: Prospective observational study conducted at university-affiliated tertial hospital in Republic of Korea from February 2022 to June 2023. KL-6 was measured before the start of PD-1/PD-L1 inhibitor treatment and tracked serially after treatment initiation or the onset of pneumonitis. Results: Eighteen patients were enrolled, and 11 had pneumonitis. Baseline KL-6 was lower in pneumonitis group without significance (261 U/ml vs 373 U/mL, P = 0.375). KL-6 level at the onset of pneumonitis was 412 U/mL, and was increased from the baseline. In non-pneumonitis group, KL-6 level was decreased from baseline in 2 patients and increased in 4 patients (Figure 1).Conclusions: Baseline KL-6 was not different between pneumonitis and non-pneumonitis group. KL-6 level showed an increasing trend in pneumonitis group but it displayed variable pattern in non-pneumonitis group.