DIFFUSE LUNG DISEASE AND LUNG TRANSPLANT NETWORK
Interstitial Lung Disease Section
Interstitial lung diseases (ILDs) are a diverse group of relentlessly progressive fibroinflammatory disorders. Pharmacotherapy includes antifibrotics and immunosuppressants as foundational strategies to mitigate loss of lung function. There has been a growing interest in telomere length and its response to immunosuppression in the ILD community.
CHEST
Dr. Mamta Chhabria
Telomeres are repetitive nucleotide sequences that “cap” chromosomes and protect against chromosomal shortening during cell replication. Genetic and environmental factors can lead to premature shortening of telomeres. Once a critical length is reached, the cell enters senescence. Short telomere length has been linked to rapid progression, worse outcomes, and poor response to immunosuppressants in idiopathic pulmonary fibrosis (IPF).
CHEST
Dr. Ryan D. Boente
Data in patients with non-IPF ILD (which is arguably more difficult to diagnose and manage) were lacking until a recent retrospective cohort study of patients from five centers across the US demonstrated that immunosuppressant exposure in patients with age-adjusted telomere length <10th percentile was associated with a reduced 2-year transplant-free survival in fibrotic hypersensitivity pneumonitis and unclassifiable ILD subgroups.1 This study was underpowered to detect associations in the connective tissue disease-ILD group. Interestingly, authors noted that immunosuppressant exposure was not associated with lung function decline in the short telomere group, suggesting that worse outcomes may be attributable to unmasking extrapulmonary manifestations of short telomeres, such as bone marrow failure and impaired adaptive immunity. Studies like these are essential to guide decision-making in the age of personalized medicine and underscore the necessity for prospective studies to validate these findings.
References
1. Zhang D, Adegunsoye A, Oldham JM, et al. Telomere length and immunosuppression in non-idiopathic pulmonary fibrosis interstitial lung disease. Eur Respir J. 2023;62(5):2300441.