Interstitial lung abnormalities: What do we know and how do we manage?

ABSTRACT

Introduction

Interstitial lung abnormalities (ILAs), which refer to mild or subtle nongravity-dependent interstitial changes, may be neglected by some clinicians due to many reasons, such as lack of diagnostic criteria for ILAs and absence of available treatments and surveillance strategies. However, without intervention, some ILAs may progress to interstitial lung disease (ILD). This review summarizes our current knowledge of this condition and ways of diagnosing it together with current management. We hope that this will lead to better recognition of ILAs.

Areas covered

We reviewed the literature on PubMed between 2008 and 2020 focusing on prevalence, etiology, symptoms, diagnostic biomarkers, clinical associations, and management of ILAs.

Expert opinion

Timely diagnosis with close monitoring of ILAs and appropriate intervention should be recognized as the management approach to ILAs. Research into ILAs should continue to improve its management.

KEYWORDS:

• Interstitial lung abnormalities
• subclinical interstitial lung diseases
• prevalence
• imaging
• biomarkers
• management

Availability of data and materials

All data generated or analyzed during this study are included in this published article [and its supplementary information files].

Article highlights

• The prevalence of ILAs is around 10% in the general population and up to 20% in the lung cancer screening population. The risk factors for ILAs include smoking, advanced age, air pollution, and gene polymorphisms.

• The classification of ILAs based on the Fleischner Society position paper separates ILAs into nonsubpleural, subpleural nonfibrotic and subpleural fibrotic lesions.

• Some serum circulating biomarkers have been correlated with ILAs, such as serum Krebs von der Lungen-6 (KL-6), surfactant protein-A (SP-A), surfactant protein-D (SP-D), and galectin 3 (Gal-3), which could be used for supporting the diagnosis of ILAs in the future.

• ILAs are associated with reduced lung function, decreased exercise capacity, increased incidence and mortality from lung cancer, and increased overall mortality.

• The priority remains to raise awareness of ILAs among clinicians and radiologists to enable early recognition, active monitoring, and appropriate management of ILAs.

Authors’ contributions

Q. Liu, H. Zhang, and F. Li developed the idea of the study, participated in its design and coordination, and helped to draft the manuscript. Q. Liu and F. Li contributed to the acquisition and interpretation of data. H.D. Jiang, K.F. Chung, and B.H. Han provided critical review and substantially revised the manuscript. All authors read and approved the final manuscript.

Additional information

Funding

This study was funded by National Key Technologies R & D Program Precision Medicine Research (No.2016YFC0901101).