Thoracic involvement of systemic lupus erythematosus: clinical, pathologic, and radiologic findings.

Thoracic involvement occurs more frequently in systemic lupus erythematosus than in any other connective tissue diseases, and more than half of patients with the disease suffer from the involvement. Primary intrathoracic manifestations include pleural disease (effusions and/or thickening), acute lupus pneumonitis, subacute interstitial lung disease including bronchiolitis obliterans organizing pneumonia and non-specific interstitial pneumonia with fibrosis, chronic interstitial lung disease of usual interstitial pneumonia, pulmonary hemorrhage, pulmonary vascular disease, small airway disease of bronchiolitis obliterans, and pulmonary arterial hypertension. Secondary intrathoracic manifestations include atelectasis due to diaphragmatic dysfunction, opportunistic pneumonia, drug and oxygen toxicity, aspiration, and pleuropulmonary consequences of cardiac and renal failure.