Interstitial Lung Disease in Connective Tissue Disease

ABSTRACT

Interstitial lung disease (ILD) is one of the most serious pulmonary complications of connective tissue diseases (CTDs), resulting in significant morbidity and mortality. ILD is frequently seen in CTDs, particularly systemic sclerosis, polymyositis/dermatomyositis, and rheumatoid arthritis; however, determining that ILD is associated with an established CTD requires the exclusion of alternative causes. Non-specific interstitial pneumonia is the most commonly observed histopathological pattern in CTD-associated ILD (CTD-ILD) except for rheumatoid arthritis, characterized by a higher frequency of usual interstitial pneumonia. Although CTD-ILD usually shows a stable or slowly progressive course, a subgroup exhibits a more severe and progressive course and requires pharmacologic intervention. Treatment strategies typically involve empirical use of immunosuppressive therapies, although a large, randomized study has examined the impact of immunosuppressive therapy for systemic sclerosis associated ILD and should also address comorbid conditions considering implementation of adjunctive therapeutic strategies. A subgroup of patients with idiopathic interstitial pneumonia who meet some, but not all, diagnostic criteria for CTDs were identified and well organized prospective studies are needed in to better determine whether evidence of autoimmunity in those plays a part in the evolution to well-defined CTDs or carries prognostic significance.