The Clinical Significance and Translational Implications of Subclinical Interstitial Lung Abnormalities in Asymptomatic Adults: A Narrative Review

This literature reports that there is a difference between interstitial lung abnormalities (ILAs) and subclinical interstitial lung abnormalities (ILAs). The objective of this narrative review was to comprehensively summarize the current knowledge on the ILA spectrum, particularly subclinical ILA. We aimed to clarify the nuanced definitions and prevalence of ILAs in asymptomatic adults, delineate their recognized risk factors, and explore the histopathological and genetic underpinnings of these conditions. This narrative literature review was conducted using relevant topic-specific keywords such as "Interstitial Lung Disease," "Subclinical Interstitial Lung Disease," "Subclinical Interstitial Lung Abnormalities," "Interstitial Lung Abnormalities," "Progression of Interstitial Lung Disease," "Subclinical Interstitial Lung Disease (ILD)," "Subclinical ILA," "Asymptomatic adults," "Computational tomography," "Incidental CT scan," "Serial CHEST CT," "Disease Progression," "Risk Factors," "Mortality," "Lung Function Tests," and "Genetic Factors." Boolean operators were used to incorporate the keywords and search on PubMed and Google Scholar, focusing on full-text open-access articles from January 2015 to July 2025. In asymptomatic adults, subclinical interstitial lung abnormalities (ILAs) were considered incidental findings. It is now increasingly being recognized that these are at least predisposing factors to early-stage interstitial lung disease, yet their clinical implications are unclear. The incidence rises with age and exposure to smoking; however, much of that evidence lacks longitudinal follow-up studies that are detailed enough to distinguish mild ILAs with benign courses and progressive disease-producing ILAs. The asymptomatic ILA management is not standardized because there is a lack of universally accepted diagnostic criteria, risk stratification assessment tools, and clearly formulated instructions referring to surveillance. To transform ILAs as incident discoveries into some clinically actionable data, there is a need to widen the views by prospective studies, the generation of biomarkers, and investigation in long-term follow-ups.