Why a 20% Emphysema Threshold May Redefine CPFE: Yet Khor, MD, PhD

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Combined pulmonary fibrosis and emphysema (CPFE) is a common phenotype in patients with interstitial lung diseases (ILD), yet most research focuses on its overlap in patients with idiopathic pulmonary fibrosis (IPF), often omitting those with other fibrotic ILDs.¹

A recent study published in CHEST found that greater extent of emphysema on CT imaging was linked to worse lung function trajectories and transplant-free survival in patients with IPF and non-IPF fibrotic lung disease alike.¹ The study validated the current definition of CPFE—emphysema extent of 15% or greater on CT imaging—while suggesting a threshold of 20% or greater may be more clinically meaningful. These data would serve patients better if validated across cohorts from different regions and health care systems, Yet H. Khor, MD, PhD, lead study author and associate professor at Monash University, said in an interview with The American Journal of Managed Care^®.

This would allow researchers and clinicians to “set a bar that’s the same across the different regions where we have a standard definitions for CPFE that’s clinically meaningful, and we can use that as a threshold moving forward,” she said.

But there are still unanswered questions regarding what tools or biomarkers might help improve diagnosis, prognostications, and treatment for patients with these diseases. Khor emphasized that patient monitoring could also stand to be improved, as spirometry doesn’t provide as accurate a picture of emphysema as researchers and clinicians would like.

“Whether it’s another method of physiological assessment, like forced oscillometry, which has been under investigation nowadays, or it’s more serial lung assessments—serial chest CT assessments—that’s going to give us the information,” she explained.

And lastly, clinical trials can stand to be more inclusive, as prior research has often excluded patients with fibrotic ILDs.

“Moving forward with pharmacotherapies in the investigation, we need to reconsider how we design clinical trials to include this group of patients in stratification of the analysis or in pre-specified subgroup analysis so that we can better understand and apply evidence-based medicine in this group of patients,” Khor concluded.

References

1. McCrear S. CPFE: why spirometry alone misses emphysema in fibrotic ILD. AJMC^®. August 31, 2026. Accessed September 10, 2026. https://www.ajmc.com/view/cpfe-why-spirometry-alone-misses-emphysema-in-fibrotic-ild