Interstitial Lung Disease in Systemic Sclerosis

Abstract

HRCT was a powerful predictor of mortality (P , 0.0005), with an optimalextentthresholdof20%.InpatientswithHRCTextentof10- 30% (termed indeterminate disease), an FVC threshold of 70% was an adequate prognostic substitute. On the basis of these observa- tions, SSc-ILD was staged as limited disease (minimal disease on HRCT or, in indeterminate cases, FVC > 70%) or extensive disease (severe disease on HRCT or, in indeterminate cases, FVC , 70%). This system (hazards ratio (HR), 3.46; 95% confidence interval (CI), 2.19-5.46; P , 0.0005) was more discriminatory than an HRCT threshold of 20% (HR, 2.48; 95% CI, 1.57-3.92; P , 0.0005) or an FVC threshold of 70% (HR, 2.11; 95% CI, 1.34-3.32; P 5 0.001). The system was evaluated by four trainees and four practitioners, with minimal and severe disease on HRCT defined as clearly , 20% or clearly . 20%, respectively, and the use of an FVC threshold of 70% in indeterminate cases. The staging system was predictive of mor- tality for all scorers, with prognostic separation higher for practi- tioners (HR, 3.39-3.82) than trainees (HR, 1.87-2.60). Conclusions: An easily applicable limited/extensive staging system for SSc-ILD, based on combined evaluation with HRCT and PFTs, provides discriminatory prognostic information.