Interstitial lung disease in systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterised by fibrosis of the skin and internal organs, autoimmune abnormalities and widespread vasculopathy. A degree of interstitial lung involvement is present in the majority of patients, although clinically significant lung fibrosis is present in approximately a third. Autoantibodies are significant clinical markers; anti-topoisomerase is tightly linked to lung fibrosis, whereas anti-centromere antibodies are protective. Further evaluation of markers of progression of lung fibrosis, such as markers of epithelial permeability, will be crucial in clinical management. The clinical course of SSc-associated interstitial lung disease is highly variable, with stability observed in a significant proportion of patients. Therefore, the decision of whether to treat is a challenging one, and should be based on evaluation of disease severity (on the basis of CT extent and lung function) and longitudinal disease behaviour. Two recently published placebo controlled randomized trials have shown a significant, if small, effect of cyclophosphamide on preventing FVC decline. However, because of the significant toxicity of cyclophosphamide, the assessment of alternative, less toxic, immunosuppressive agents for the long-term management of SSc-associated interstitial lung disease is needed.