Researchers have discovered that serum Krebs von den Lungen-6 (KL-6) level may be a useful biomarker of disease progression in idiopathic pulmonary fibrosis (IPF), as published in Scientific Reports.

IPF is a progressive fibrosing interstitial pneumonia that carries a poor prognosis, with a median survival of only 3 to 5 years. Currently, physiological parameters obtained from pulmonary function tests provide physicians with important information regarding the disease progression of IPF. 

Recently, scientists have looked into the possibility of using blood biomarkers to measure disease progression. Among them, KL-6 appears to be a good candidate since an elevated level of KL-6 has already been used to predict mortality.

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However, the role of biomarkers in predicting IPF disease progression is ill-defined. The researchers of the study hence set out to evaluate the clinical usefulness of serum biomarkers, including KL-6, to predict disease progression in IPF. 

Read more about IPF prognosis

The research team recruited 74 patients with IPF who had their KL-6 level and monocyte count measured at least twice. The cut-off values for disease progression were ≥1000 U/mL for KL-6 and ≥600 /μL for monocytes. Disease progression was defined as a 10% reduction in forced vital capacity and/or a 15% decrease in the diffusing capacity of the lung for carbon monoxide relative to the baseline. 

The study revealed that the baseline serum KL-6 level was increased in patients with IPF who experienced disease progression. “These findings suggest that the baseline serum KL-6 level might be a useful predictive marker for the disease progression in IPF,” the researchers wrote. In contrast, a high monocyte count was not associated with disease progression in this study.

This study suggests that serum KL-6 level as a laboratory investigation can be incorporated into clinical practice as a useful biomarker for predicting clinical outcomes and prognosis.


Chung C, Kim J, Cho HS, Kim HC. Baseline serum Krebs von den Lungen-6 as a biomarker for the disease progression in idiopathic pulmonary fibrosisSci Rep. 2022;12(1):8564. doi:10.1038/s41598-022-12399-8