Fibrotic Pulmonary Sarcoidosis—From Pathogenesis to Management

Abstract

Sarcoidosis is a multiorgan, granulomatous disease of an unknown etiology. The characteristic feature of the disease is the formation of noncaseating granulomas. Spontaneous resolution occurs in most patients, but the clinical course may be chronic or progressive, complicated by pulmonary fibrosis, which is a major cause of mortality in sarcoidosis. Recent studies have provided new information on the immunological mechanisms of pulmonary fibrosis. Its pathogenesis includes the alteration of lymphocyte activity and the imbalance between their subpopulations, the polarization of macrophages to the profibrotic phenotype, and an imbalance between the activity of metalloproteinases and their tissue inhibitors. A multidisciplinary approach is required for the optimal management of fibrotic pulmonary sarcoidosis. Clinical symptoms, serum biomarkers, imaging, pulmonary function test results, other organ involvement, comorbidities, and complications should be considered when assessing disease activity and selecting the most appropriate treatment. The use of anti-inflammatory drugs is often discussed. There has been no consensus reached on whether antifibrotic agents should be added or used in monotherapy as initial treatment in such cases. This article will review all the information on fibrotic pulmonary sarcoidosis and present factors associated with fibrosis development, prognosis, and treatment options.