Pulmonary Involvement in Autoimmune-Mediated Disease

Pulmonary involvement in the form of interstitial lung disease (ILD) is an important organ manifestation of many autoimmune diseases (AID). The management of ILD in different types of AID is described.

This review is based on pertinent publications retrieved by a search in PubMed, with particular emphasis on meta-analyses and randomized controlled trials, supplemented by guidelines, expert consensus statements, and the authors' clinical experience.

The prevalence of ILD among patients with inflammatory rheumatic systemic diseases ranges from 7% to 50% (7-15% in rheumatoid arthritis, 44-50% in systemic sclerosis, and 33-50% in idiopathic inflammatory myopathies). ILD is much less common in organ-specific types of AID (e.g., multiple sclerosis). ILD takes a progressive, fibrosing course in 16-40% of cases. If the patient's history or clinical manifestations suggest the possibility of ILD, pulmonary function tests and thin-slice computed tomography of the lung (high-resolution computed tomography, HRCT) should be performed. Patients with types of AID associated with a high prevalence of ILD should undergo regular pulmonary function testing in addition to directed history-taking and lung auscultation. Pulmonary HRCT should be performed on initial diagnosis of an AID. Invasive measures are needed only to resolve differential diagnostic uncertainty. The pharmacotherapy of ILD is initially oriented toward the immune-modulating or immunosuppressive treatment of the underlying disease. Antifibrotic treatment is given in addition in cases of progressive pulmonary fibrosis. The management of ILD should ideally be decided on by an interdisciplinary ILD board. The prognosis of ILD depends on that of the underlying disease; ILD is associated with elevated mortality.

ILDs are critical manifestations of a variety of systemic autoimmune and inflammatory rheumatic diseases. Early recognition and targeted pharmacotherapy optimize the clinical outcome.