Interstitial Lung Abnormalities: Recognition, Risk Stratification, and When to Act

An interstitial lung abnormality (ILA) discovered incidentally on chest CT can be a difficult finding to communicate: the patient feels well, nothing requires immediate treatment, and yet the discovery carries real prognostic weight. Between 20% and 60% of ILAs progress to interstitial lung disease (ILD) over 2 to 5 years — making early recognition and structured follow-up important, and making the absence of a standardized management framework a genuine clinical problem.1 That framework arrived in May 2025, when the American Thoracic Society published its first formal clinical practice guidelines on ILA evaluation and management.2

Jessica Glennie, MSN, APRN, of the Cleveland Clinic ILD Center in Cleveland, Ohio, addressed ILAs in her session at APAP 2026, calling the findings "almost like the origin story of interstitial lung disease."1 She described the new ATS guidelines as a meaningful improvement over prior Fleischner Society guidance — providing more granular direction on monitoring intervals, biomarker testing, and which patient subgroups warrant closer surveillance.

One of the more clinically consequential changes in the 2025 ATS guidelines is the reclassification of high-risk populations, including patients with connective tissue diseases such as rheumatoid arthritis and scleroderma. Previously, these patients were excluded from ILA classification because their findings were considered attributable to known underlying disease. The new guidelines permit an ILA designation in these patients, with the recognition that they carry elevated progression risk and require more intensive monitoring — a change Glennie called important for guiding follow-up in patients she routinely sees in the ILD clinic.2

For APPs encountering an ILA for the first time on a scan, she emphasized risk factor management as a unifying priority regardless of ILA subtype: smoking cessation, vaccination to reduce the risk of pneumonia and respiratory infections that can accelerate progression, and optimization of any underlying rheumatologic disease in coordination with rheumatology. Monitoring frequency — CT scans and pulmonary function testing — should be guided by whether the ILA has fibrotic features and other risk factors for progression per the ATS framework.2

Counseling the patient who feels well and is surprised by the finding requires calibration. Glennie described her approach as honest about the range of outcomes — many ILAs do not progress — while being clear that some do, and that the goal of surveillance is to catch progression early and intervene before function declines. "You sit down with that patient and explain what we find, talk about those percentages of patients that can progress, and then make sure that any risk factors they have are managed," she said. "It's usually a good discussion of preventative medicine."

Integration of the new guidelines into practice is still lagging, she acknowledged — a predictable dynamic for guidance released less than a year ago — but she anticipates their adoption will accelerate as APPs and other clinicians become more familiar with the updated framework.

Glennie has no disclosures to report.

References

1. Glennie J. ILAs. Presented at: APAPP National Conference 2026, June 18-20; Las Vegas, NV.
2. Raghu G, Remy-Jardin M, Richeldi L, et al. Approach to the evaluation and management of interstitial lung abnormalities: an official ATS clinical practice guideline. Am J Respir Crit Care Med. 2025. doi:10.1164/rccm.202503-0617ST