Interstitial Lung Disease in Idiopathic Inflammatory Myopathy

The lung is one of the most common extra-muscular targets in idiopathic inflammatory myopathies (IIM) and interstitial lung disease (ILD) is a prevalent and often devastating manifestation of IIM. IIM-associated ILD (IIM-ILD) contributes to nearly 80% of the mortality in IIM with a reported prevalence of 65% of newly diagnosed IIM cases. Although ILD frequently accompanies clinical and laboratory findings of myositis, overt signs of muscle disease may be absent in the setting of significant lung disease. Understanding the varied scope of presentation of these diseases is essential to providing optimal patient care. This review will provide an in depth examination of ILD in IIM both from a rheumatologic and pulmonary perspective and will discuss the scope of disease, presenting features, genetic associations, pathogenesis, diagnosis, radiographic and histopathologic findings, along with biomarker assessment and a rationale for therapeutic intervention.