Research progress of KL-6 in respiratory system diseases

Abstract

This article comprehensively elucidates the discovery of Krebs von den Lungen-6 (KL-6), its structural features, functional mechanisms, and the current research status in various respiratory system diseases. Discovered in 1985, KL-6 was initially considered a tumor marker, but its elevated levels in interstitial lung disease (ILD) led to its recognition as a relevant serum marker for ILD. KL-6 is primarily produced by type 2 alveolar epithelial cell regeneration. Over the past 30 years since the discovery of KL-6, the number of related research papers has steadily increased annually. Following the coronavirus disease 2019 (COVID-19) pandemic, there has been a sudden surge in relevant literature. Despite KL-6's potential as a biomarker, its value in the diagnosis, treatment, and prognosis varies across different respiratory diseases, including ILD, idiopathic pulmonary fibrosis (IPF), COVID-19, and lung cancer. Therefore, as an important serum biomarker in respiratory system diseases, the value of KL-6 still requires further investigation.

Keywords:

• KL-6
• respiratory diseases
• biomarkers

Acknowledgments

We thank Untitled (https://www.biorender.com/) for providing us with a drawing platform.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This review was supported by the Major Projects of Institute of Science and Technology, National Health Commission [2021KYSHX00601].