Both SLE and RA are connective tissue diseases which are characterized by the presence of auto-immune antibodies and subsequent organ damage. The lung is frequently affected in CTDs.
Systemic lupus erythematosus is a chronic autoimmune disease affecting multiple systems, characterized by periods of relapses and remissions, with the thoracic involvement has a high rate of prevalence. Pulmonary involvement can include pleura, lung parenchyma and pulmonary vessels, with higher morbidity and mortality rates. pleural disease is the most common thoracic manifestation in SLE patients. HRCT is crucial in detecting pulmonary involvement.
Rheumatoid arthritis stands out as the most prevalent form of inflammatory arthritis. As the disease advances, many patients experience thoracic involvement. All components of the respiratory tract can be affected by RA, with the pleural disease is the most common thoracic manifestation.
Thoracic manifestations, particularly RA-ILD, significantly elevate rates of morbidity and mortality among RA patients. The assessment of disease extent via HRCT can predict survival in RA-ILD. The HRCT is also found to be more sensitive than pulmonary function testing in diagnosing asymptomatic patients with small airway disease.