Interstitial lung disease in systemic sclerosis: progress in screening and early diagnosis

Interstitial lung disease (ILD) is the major determinant of morbidity and mortality in systemic sclerosis (SSc). In highly selected SSc patients, it was recently shown that stem cell therapy early in the disease course improved survival and reduced the extent of ILD, providing a rationale for early ILD detection strategies in this disease. Here, we review recent progress on ILD screening and early diagnosis in SSc.

Two studies showed that over 60% of unselected SSc cases with ILD by high-resolution computer tomography (HRCT) had normal range pulmonary function tests (PFTs); indicating poor performance of PFTs for ILD screening purposes. Serial, paired HRCT and PFT analyses indicated that screening by HRCT at baseline predicted risk for lung fibrosis development, progression rate of fibrosis and PFT decline. Analyses of circulating biomarkers, like CCL18, and nonradiating lung imaging modalities, like ultrasound and MRI, showed promise as tools for early ILD detection; but further work is needed.

Prospective cohort data indicated poor performance of PFT as a stand-alone method for ILD screening. Lung HRCT appeared promising, but radiation is an issue. Promising biomarker data indicate the possibility of new ILD screening algorithms in SSc.