What autoimmune disease is associated with pulmonary inflammation?

From the Guidelines

Autoimmune diseases that can cause inflammation in the lungs include rheumatoid arthritis, systemic lupus erythematosus (SLE), scleroderma, and Sjögren's syndrome, with rheumatoid arthritis being one of the most common causes of interstitial lung disease. These conditions can lead to various pulmonary manifestations, such as interstitial lung disease, lupus pneumonitis, pleuritis, pulmonary fibrosis, and interstitial pneumonia. According to the most recent evidence from 1, interstitial lung diseases (ILDs) are a heterogeneous group of diffuse lung parenchymal disorders that are one of the most common pulmonary manifestations of systemic rheumatic diseases.

The epidemiology of ILD in the context of connective tissue disease (CTD) is difficult to determine due to undefined classification criteria, overlap syndromes, and undifferentiated CTD. However, nearly 20% of ILDs reported in Europe and the USA are associated with autoimmune rheumatic diseases, contributing to significant morbidity and early mortality in this setting 1.

Some key points to consider include:

• Rheumatoid arthritis often leads to interstitial lung disease, with symptoms including shortness of breath and dry cough.
• SLE can cause lupus pneumonitis or pleuritis, while scleroderma frequently leads to pulmonary fibrosis.
• Sjögren's syndrome may cause interstitial pneumonia.
• Other relevant conditions include granulomatosis with polyangiitis (formerly Wegener's), which causes granulomatous inflammation in the lungs, and sarcoidosis, characterized by granulomas in multiple organs including the lungs.
• Treatment typically involves immunosuppressive medications like corticosteroids (prednisone), methotrexate, azathioprine, or biologics such as rituximab, with the specific regimen depending on the underlying disease and severity, as recommended by 1 and 1.

It's essential to note that these conditions cause lung inflammation through autoimmune mechanisms where the immune system mistakenly attacks lung tissue, leading to chronic inflammation and potential scarring if left untreated. Early detection and accurate diagnosis are crucial for informed treatment decisions and prognosis, as emphasized by 1 and 1.

In terms of specific guidance, a recent study 1 provides practical guidance for the early recognition and follow-up of patients with connective tissue disease-related interstitial lung disease, highlighting the need for a multidisciplinary approach and the importance of considering disease evaluation, patient follow-up, and treatment strategy. Another study 1 discusses the challenges in the early recognition of progressive CTD-ILD and the need for collaboration between rheumatologists and pulmonologists.

Overall, the most effective approach to managing autoimmune diseases that cause inflammation in the lungs is to prioritize early detection, accurate diagnosis, and timely treatment, with a focus on minimizing morbidity, mortality, and improving quality of life, as supported by the latest evidence from 1, 1, 1, 1, 1, 1, and 1.

From the Research

Inflammation in Lungs and Autoimmune Disease

• Inflammation in the lungs can be associated with various autoimmune diseases, with Rheumatoid Arthritis (RA) being a prominent example 2, 3, 4, 5, 6.
• RA is a chronic inflammatory autoimmune disorder that can affect extra-articular regions, including the lungs, leading to interstitial lung disease (ILD) 3, 4, 5, 6.
• RA-ILD is a significant cause of morbidity and mortality in RA patients, with a prevalence of around 3-5% 2, 4.
• The pathogenesis of RA-ILD is associated with anti-cyclic citrullinated peptide antibodies, MUC5B mutation, and smoking 4.
• Diagnostic methods for RA-ILD include high-resolution computed tomography (HRCT) imaging and pulmonary function tests 4, 6.
• Treatment options for RA-ILD include disease-modifying anti-rheumatic drugs (DMARDs), glucocorticoids, and biologic agents, such as methotrexate, leflunomide, abatacept, and rituximab 2, 4, 5.

Characteristics of RA-ILD

• RA-ILD can manifest as various histopathologic patterns, including usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP) 2, 6.
• UIP is the most common and severe subtype of RA-ILD, sharing clinical and histopathologic features with idiopathic pulmonary fibrosis 6.
• RA-ILD is associated with significant morbidity and mortality, and patients are at high risk of infection and drug toxicity 6.
• Risk factors for RA-ILD include older age, male sex, ever smoking, and seropositivity for rheumatoid factor and anti-cyclic citrullinated peptide 6.