Systemic Autoimmune Rheumatic Disease-Associated Interstitial Lung Disease: A Pulmonary Perspective on Recent Guidelines.

Systemic autoimmune rheumatic disease-associated interstitial lung disease (SARD-ILD) represents a heterogeneous group of pulmonary disorders with substantial effects on morbidity and mortality. The clinical course varies according to the underlying rheumatic disease, radiological phenotype, extent of lung involvement and risk of progression. Although interstitial lung disease is particularly frequent in systemic sclerosis and idiopathic inflammatory myopathies, it also significantly contributes to outcomes in rheumatoid arthritis, Sjögren's disease and mixed connective tissue disease. Early recognition is essential, as clinically silent disease may progress to irreversible fibrosis, whereas some patients may present with rapidly progressive or progressive fibrosing phenotypes requiring urgent or intensified treatment. Recent American College of Rheumatology/American College of Chest Physicians (ACR/CHEST) and European Respiratory Society/European Alliance of Associations for Rheumatology (ERS/EULAR) guidelines provide an important framework for screening, monitoring and management of SARD-ILD, but differ in several clinically relevant aspects. ACR/CHEST adopts a largely risk-based and pragmatic approach, whereas ERS/EULAR places greater emphasis on disease-specific assessment, the central role of high-resolution computed tomography in screening and structured monitoring according to progression risk. In treatment, both guidelines support immunosuppression as the main therapeutic strategy, while recognizing the growing role of antifibrotic therapy in selected patients with fibrotic or progressive disease. The available evidence remains strongest for systemic sclerosis-associated interstitial lung disease, with important uncertainties persisting across other SARD subtypes. This narrative review summarizes the epidemiology, clinical and radiological phenotypes, and pathobiological basis of SARD-ILD, and critically discusses recent guideline recommendations from a pulmonary perspective. Particular emphasis is placed on translating the differences between the current guidelines into practical multidisciplinary decisions regarding screening, longitudinal assessment, treatment selection and future research priorities.