Interstitial lung disease in systemic sclerosis - 10/03/09

Introduction Interstitial lung disease (ILD) associated with systemic sclerosis (SSc) is mainly encountered in patients with diffuse disease although it may occur less frequently in patients with limited cutaneous disease.

Background ILD should be detected early in the course of the disease with the help of high resolution computerised tomography (HRCT) and pulmonary function tests (PFT). Altogether, up to 75% of SSc patients develop ILD. However, ILD is progressive in only a minority of patients. Unlike idiopathic ILD, SSc associated ILD corresponds to non-specific interstitial pneumonia (NSIP) in most cases, whereas usual interstitial pneumonia (UIP) is encountered less frequently. This explains the better prognosis of SSc associated ILD compared to idiopathic ILD. Nevertheless, ILD represents one of the two main causes of death in SSc.

Viewpoint The treatment of SSc associated ILD is not very well established. Anti-fibrosing treatments have failed to demonstrate any benefit and cyclophosphamide, which has been used in the treatment of this condition for about 15 years, has recently been evaluated in two prospective randomised studies which showed a significant but modest effect on respiratory function.

Conclusion A subgroup of patients with rapidly progressive ILD might benefit from pulsed intravenous cyclophosphamide combined with prednisone 15 mg daily but this remains to be confirmed.