Serial KL-6 Changes in PD-1/PD-L1 Inhibitor-Related Pneumonitis in Non-small Cell Lung Cancer: A Single-Center Prospective Pilot Study
- Author:
Jae Kyeom SIM
1
;
Juwhan CHOI
;
Sung Won CHANG
;
Sang Hyuk KIM
;
Jee Youn OH
;
Kyung Hoon MIN
;
Gyu Young HUR
;
Hwan Seok YONG
;
Jae Jeong SHIM
;
Sung Yong LEE
Author Information
- Publication Type:Original Article
- From:Tuberculosis and Respiratory Diseases 2026;89(2):257-265
- CountryRepublic of Korea
- Language:English
-
Abstract:
Background:Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective treatments for non-small cell lung cancer (NSCLC), but their use can lead to severe pneumonitis. This study aims to evaluate the utility of Krebs von den Lungen-6 (KL-6) for predicting and diagnosing PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients.
Methods:We conducted a prospective observational study at a university-affiliated tertiary hospital in Korea from February 2022 to June 2023. Baseline KL-6 levels were measured immediately before initiating PD-1/PD-L1 inhibitor therapy. In patients who developed pneumonitis, KL-6 levels were monitored every 1–2 weeks from the onset of pneumonitis. For patients without pneumonitis, KL-6 levels were measured every 6 weeks. We compared clinical characteristics and serial KL-6 levels between the pneumonitis and non-pneumonitis groups.
Results:Eighteen patients were enrolled, with 11 developing pneumonitis. Baseline KL-6 levels did not significantly differ between the two groups (261 U/mL in the pneumonitis group vs. 373 U/mL in the non-pneumonitis group, p=0.375). In the pneumonitis group, KL-6 levels generally showed an upward trend, with a median of 412 U/mL at pneumonitis onset. Conversely, KL-6 levels in the non-pneumonitis group showed no clear overall change.
Conclusion:In this pilot study, baseline KL-6 was not clearly linked to PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. However, increases in KL-6 levels post-baseline were more frequently observed in patients who developed pneumonitis, including cases of all-cause pneumonitis.
