State of the Art: The Relationship Between GERD and Interstitial Lung Disease

Background: Interstitial lung diseases (ILDs) are progressive fibrotic lung disorders associated with substantial morbidity and mortality. Gastroesophageal reflux disease (GERD) is increasingly recognized as a common comorbidity in ILD, particularly in idiopathic pulmonary fibrosis (IPF) and connective tissue disease-associated ILD (CTD-ILD), though its clinical significance remains incompletely understood. Methods: We reviewed current evidence regarding the epidemiology, pathophysiology, diagnosis, and management of GERD in ILD, including reflux prevalence, mechanisms of lung injury, pharmacologic and surgical therapies, and transplant-related outcomes. Results: GERD affects more than 50% of patients with ILD and up to 90% of individuals with IPF on objective reflux testing, frequently without classic symptoms. Experimental and clinical studies suggest that recurrent microaspiration of gastric contents may contribute to fibrotic lung injury through epithelial damage, inflammatory signaling, and fibroblast activation. Genetic studies further support an association between GERD predisposition and increased lifetime risk of IPF. Despite these findings, current evidence has not established GERD as a definitive modifiable risk factor for ILD progression. Antacid therapy has not consistently improved lung function decline, exacerbation rates, or mortality in IPF. In contrast, anti-reflux surgery appears beneficial in lung transplant recipients with GERD and is associated with improved allograft outcomes and survival. Conclusions: GERD is strongly associated with ILD, but causality and optimal management strategies remain uncertain. Prospective studies with objective reflux assessment are needed to clarify the role of GERD in ILD progression and guide targeted treatment strategies.