Interstitial lung disease in systemic sclerosis: Pathophysiology and therapy

Systemic sclerosis or scleroderma (SSc) is an autoimmune disease characterized by a widespread microangiopathy, immune system alterations and fibrosis of the skin and internal organs. Lung involvement is a frequent complication and interstitial lung disease (ILD) represents a leading cause of morbidity and mortality in SSc patients. Unlike idiopathic ILD, SSc-ILD corresponds to non-specific interstitial pneumonia (NSIP) in most cases, whereas usual interstitial pneumonia (UIP) is less frequently encountered. Therefore, the prognosis of SSc-ILD is better than that for idiopathic ILD. However, in a small number of cases, it may progress rapidly to end-stage respiratory insufficiency. Thoracic high-resolution computed tomography (HRCT), pulmonary function tests (PFT) including carbon monoxide diffusing capacity (DLCO) and 6-minute walk (6MWT) test with measurement of oxygen saturation are essential at the time of diagnosis of SSc. Generally, a lung biopsy is not needed in patients with SSc-ILD, except in the case of a discrepancy between clinical manifestations and HRCT findings. Treatment of ILD remains disappointing although many promising therapies are emerging. Cyclophosphamide (CYC), which has been used for 20 years, has recently been evaluated in two prospective randomized studies that failed to demonstrate a major benefit for lung function. Mycophenolate mofetil, azathioprine and rituximab are as alternatives to CYC. Promising cellular and molecular targeted anti-fibrotic therapeutic options have emerged. Lung transplantation can be proposed in the absence of other major organ involvement. © 2013 Nova Science Publishers, Inc.