Patients with Interstitial Lung Disease Secondary to Autoimmune Diseases: How to Recognize Them?

Abstract

The diagnostic assessment of patients with Interstitial Lung Disease (ILD) can be challenging due to the large number of possible causes. Moreover, the diagnostic approach can be limited by the severity of the disease, which may not allow invasive exams. To overcome this issue, the referral centers for ILD organized Multidisciplinary Teams (MDTs), including physicians and experts in complementary discipline, to discuss the management of doubtful cases of ILD. MDT is currently considered the gold standard for ILD diagnosis, but it is not often simple to organize and, furthermore, rheumatologists are still not always included. In fact, even if rheumatologic conditions represent a common cause of ILD, they are sometimes difficult to recognize, considering the variegated clinical features and their association with all possible radiographic patterns of ILD. The first objective of this review is to describe the clinical, laboratory, and instrumental tests that can drive a diagnosis toward a possible rheumatic disease. The secondary objective is to propose a set of first-line tests to perform in all patients in order to recognize any possible rheumatic conditions underlying ILD.

Keywords: Raynaud’s phenomenon; Sjögren’s syndrome; antisynthetase syndrome; idiopathic pulmonary fibrosis; interstitial lung disease; interstitial pneumonia with autoimmune features; multidisciplinary team; myositis; nailfold videocapillaroscopy; systemic sclerosis.

Figure 1

The hands in patients with Interstitial Lung Disease (ILD) secondary to rheumatic conditions. (A): Raynaud’s phenomenon in ischemic phase during a provocation test; (B): mechanic’s hands; (C,D): Gottron’s signs; (E): Gottron papules; (F): sclerodactyly with clawed shape in systemic sclerosis; (G): pitting scars in a patient with systemic sclerosis.

Figure 2

Spectrum of autoantibodies associated with autoimmune interstitial lung disease. Legend: AAVs: ANCA (Anti-Neutrophil Cytoplasm Antibody)-Associated Vasculitis; ACPA: Anti-Citrullinated Protein Antibody; ANA: Antinuclear Antibodies; APLA: Anti-phospholipid antibodies; ATSA: Anti-T-RNA-synthetase antibodies; IIMs: Idiopathic Inflammatory Myopathies; IPAF: Interstitial Pneumonia with Autoimmune Features; MAAs: Myositis-associated antibodies; MSAs: Myositis-specific antibodies; RA: Rheumatoid Arthritis; RF: Rheumatoid Factor SjS: Sjögren’s Syndrome; SSDs: Scleroderma Spectrum Disorders.

Figure 3

Legend: AAV: ANCA-Associated Vasculitis; LIP: Lymphocytic Interstitial Pneumonia; IPAF: Interstitial Pneumonia with Autoimmune Features; IIMs: Idiopathic Inflammatory Myopathies; NSIP: Non-Specific Interstitial Pneumonia; RA: Rheumatoid Arthritis; SLE: Systemic Lupus Erythematosus; SjS: Sjögren’s Syndrome; SSD: Scleroderma Spectrum Disorders; UIP: Usual Interstitial Pneumonia.

Figure 4

Our methodology in the diagnostic assessment of patients with interstitial lung disease. Legend: AAV: ANCA-Associated Vasculitis; ALT: Alanine Transaminase; ACA: Anticentromere Antibody; ACPA: Anti-Citrullinated Protein Antibody; ANA: Antinuclear Antibody; ANCA: Anti-Neutrophil Cytoplasmic Antibody; AST: Aspartate Transaminase; C3 and C4: Complement Fraction 3 and 4; CPK: Creatine Phosphokinase; CRP: C-Reactive Protein; DsDNA: Double-Stranded DNA; ESR: Erythrocyte Sedimentation Rate; HRCT: High-Resolution Computed Tomography; LDH: Lactic Dehydrogenase; NVC: Nailfold Video Capillaroscopy; PET: Positron Emission Tomography; PFTs: Pulmonary Function Tests; RF: Rheumatoid Factor.