Sjögren’s Syndrome is a chronic autoimmune condition primarily recognized for affecting moisture-producing glands, leading to symptoms like dry eyes and mouth. Beyond these glandular effects, it can also manifest systemically, impacting various organs throughout the body. For some individuals, lung involvement is a significant extraglandular manifestation.
The Autoimmune Link to Lung Involvement
Sjögren’s Syndrome is an autoimmune disease where the immune system mistakenly attacks healthy tissues, causing inflammation and damage. This systemic inflammation can extend to the respiratory system, influencing the airways, lung tissue, and blood vessels.
The underlying mechanism involves an infiltration of specific white blood cells, predominantly CD4+ T cells, into various tissues, including the submucosa of the bronchial and bronchiolar airways. This cellular infiltration contributes to lung inflammation. Epithelial cells within the lungs may also play a role in initiating and sustaining this autoimmune process.
Common Lung Manifestations
Sjögren’s Syndrome can affect the lungs in several distinct ways. These pulmonary manifestations can range from inflammation and scarring of lung tissue to issues affecting the airways, blood vessels, and even increasing the risk of certain growths.
Interstitial Lung Disease (ILD) is a common and serious lung complication in Sjögren’s. Nonspecific Interstitial Pneumonia (NSIP) is recognized as the most frequent pattern of ILD, often presenting with ground-glass opacities and reticular abnormalities on imaging. Lymphocytic Interstitial Pneumonia (LIP) is another pattern characterized by widespread infiltration of lymphocytes and plasma cells within the lung, which can lead to cysts and thickened bronchovascular bundles. Usual Interstitial Pneumonia (UIP), while less common, also involves a fibrotic, scarring process.
Airway diseases are also frequently observed in Sjögren’s Syndrome, affecting the trachea, bronchi, and bronchioles. Bronchiectasis, a condition where airways become abnormally widened, can lead to mucus buildup and recurrent infections. Bronchiolitis, inflammation of the small airways, is considered the most frequent airway disease and can manifest as follicular bronchiolitis, characterized by lymphoid follicles around the bronchioles. Chronic bronchitis, along with dryness of the trachea and bronchi (xerotrachea), can also be present.
Pulmonary hypertension, defined by high blood pressure in the lung arteries, is a less common but serious complication that can arise in Sjögren’s Syndrome. This condition can result from various mechanisms, including issues with blood vessels or other lung complications.
Pleural involvement, which is inflammation of the lining around the lungs, is a less frequent manifestation. Fluid accumulation around the lungs (pleural effusion) can occur. Lymphoproliferative disorders are another concern, as Sjögren’s Syndrome is associated with an increased risk of certain lymphomas. Lymphocytic infiltration can progress, and in some cases, lead to a type of non-Hodgkin lymphoma called mucosa-associated lymphoid tissue (MALT) lymphoma.
Identifying Lung Symptoms
Individuals with Sjögren’s-related lung involvement may experience a range of respiratory symptoms. A persistent dry cough is a common symptom, sometimes referred to as ‘xerotrachea.’ This cough is often non-productive.
Shortness of breath, also known as dyspnea, is frequently reported, especially with physical exertion. Wheezing or a sensation of chest tightness may also occur. Recurrent respiratory infections, such as pneumonia or bronchitis, can occur, particularly in those with conditions like bronchiectasis. Fatigue, which can be a general symptom of Sjögren’s, can also be related to reduced lung function. Less commonly, chest pain can be a symptom, especially if there is pleural involvement.
Diagnosing and Managing Lung Complications
Diagnosing lung complications in Sjögren’s Syndrome involves a clinical evaluation, starting with a detailed patient history and a physical examination. Pulmonary Function Tests (PFTs) are often performed to measure lung capacity and airflow, helping to identify restrictive or obstructive patterns of lung disease.
Imaging studies are important for diagnosis, with High-Resolution Computed Tomography (HRCT) of the chest being key. HRCT scans can reveal specific patterns of lung disease, such as ground-glass opacities, reticular abnormalities, or bronchiectasis, which may not be visible on standard chest X-rays. In some instances, a bronchoscopy or lung biopsy may be necessary to confirm a diagnosis, especially for interstitial lung diseases or to differentiate from other conditions.
Management strategies for Sjögren’s-related lung complications are tailored to the specific type and severity of lung involvement. Immunosuppressive therapy is a primary approach, aimed at reducing the overactive immune system. Medications such as corticosteroids are often used to reduce inflammation, and other disease-modifying antirheumatic drugs (DMARDs) may also be prescribed. For fibrotic ILD, anti-fibrotic medications can be considered.
Symptomatic treatments alleviate discomfort and improve lung function. These can include bronchodilators to help open airways, oxygen therapy for individuals with low oxygen levels, and mucolytics to assist with mucus clearance. Preventing and treating infections is a key aspect of care, which may involve vaccinations and antibiotics for bacterial infections. Lifestyle modifications, such as smoking cessation, are also recommended to support lung health. Regular monitoring with pulmonologists and rheumatologists is important for ongoing assessment and adjustment of treatment plans.