Clinical Manifestations and Management of Fibrotic Pulmonary Sarcoidosis

Abstract

Fibrotic pulmonary sarcoidosis represents a distinct and relatively uncommon manifestation within the spectrum of sarcoidosis and has substantial morbidity and mortality. Due to the scarcity of research focused on this specific disease subtype, our current understanding of pathogenesis and optimal management remains constrained. This knowledge gap underscores the need for further investigation into areas such as targeted therapies, lung transplantation, and quality of life of patients with fibrotic pulmonary sarcoidosis. The primary aim of this review is to discuss recent developments within the realm of fibrotic pulmonary sarcoidosis to foster a more comprehensive understanding of the underlying mechanisms, prognosis, and potential treatment modalities.

Keywords: advanced pulmonary sarcoidosis; fibrotic pulmonary sarcoidosis; pulmonary fibrosis; sarcoidosis.

Figure 1

Drivers that may be involved in fibrotic pulmonary sarcoidosis. GREM1, gremlin 1; TLR3, toll-like receptor 3; ANXA11, annexin 11; Tregs, T-regulatory cells; Th17, T-helper 17 cells; mTOR, mammalian target of rapamycin complex 1; HIF1α, hypoxia inducible factor 1; CCL-18, C-C motif chemokine ligand 18.

Figure 2

Images of three patients with advanced pulmonary sarcoidosis: patient 1 with biapical cavities and mycetoma (asterisk) on chest X-ray (A), large biapical bronchiectatic cavities (arrows) on coronal image of CT chest (B), right apical mycetoma (asterisk) and extensive left-sided upper-zone predominant fibrosis (arrow head) of anterior lung on axial image of CT chest (C); patient 2 with enlarged pulmonary artery diameter (45 mm) on axial image of CT chest (D); patient 3 with bilateral irregular reticular and nodular fibrosis (arrow head) on coronal image of CT chest (E) with air trapping (arrow) on axial image of CT chest (F).

Figure 3

FDG-PET/CT imaging of a 68-year-old male with fibrotic pulmonary sarcoidosis on chronic methotrexate with metabolically active infiltrates (arrows) in the right upper lobe and left upper lobe extending into the pleura (A,B); reduced density and activity on follow-up imaging 12 months after the addition of anti-TNF-alpha inhibitor (C,D).

Figure 4

Simplified algorithm for the management of fibrotic pulmonary sarcoidosis. *Investigations with pulmonary function test, 6-min walk test, high-resolution computed tomography, echocardiogram, and fluorodeoxyglucose positron emission tomography integrated with computed tomography.