Interstitial lung disease in scleroderma

Abstract

Systemic sclerosis is a heterogeneous disease of unknown etiology with limited effective therapies. It is characterized by autoimmunity, vasculopathy, and fibrosis and is clinically manifested by multiorgan involvement. Interstitial lung disease is a common complication of systemic sclerosis and is associated with significant morbidity and mortality. The diagnosis of interstitial lung disease hinges on careful clinical evaluation and pulmonary function tests and high-resolution computed tomography. Effective therapeutic options are still limited. Several experimental therapies are currently in early-phase clinical trials and show promise.

Keywords: Diagnosis; Fibrosis; Interstitial lung disease; Pathogenesis; Systemic sclerosis; Treatment.

Figure 1. Key mediators in the pathogenesis of pulmonary fibrosis in SSc

Pulmonary fibrosis is initiated by damage to the vasculature and lung parenchyma, resulting in endothelial and epithelial cell injury. This subsequently results in the release of a number of cytokines and growth factors which in turn activate fibroblasts, resulting in extracellular matrix deposition and ultimately fibrosis. CTGF, connective tissue growth factor; TGF-β, transforming growth factor beta.

Figure 2. Representative radiographic findings on high-resolution computed tomography

a) subpleural ground glass opacities (white arrows) and traction bronchiectasis consistent with nonspecific interstitial pneumonia, and b) honeycombing (black arrow), bronchiectasis and ground glass opacities suggestive of usual interstitial pneumonia.