Fibrocytes and Progression of Fibrotic Lung Disease: Ready for Showtime?

摘要

Hermansky-Pudlak syndrome (HPS) is group of autosomal recessive disorders, of which three subtypes, HPS-1, HPS-2, and HPS-4, reproducibly result in interstitial lung disease (ILD). The nature of the hereditary mutation allows ILD to develop at much younger ages than seen in idiopathic pulmonary fibrosis (IPF), and the corresponding presence of albinism in these patients allows a unique opportunity to identify patients at very high risk of developing lung fibrosis before the disease process is well established. In this issue of the Journal, Trimble and colleagues (pp. 1395-1401) studied a group of 65 patients with HPS to correlate circulating fibrocytes with measures of lung fibrosis in a cross-sectional and longitudinal analysis. They found that patients with HPS with ILD had elevated numbers of fibrocytes in their circulation when compared with patients with HPS without ILD or with normal control patients. Interestingly, the increased fibrocytes seen in patients with ILD were driven by a subset of patients with very high counts (n = ～10). This is reminiscent of previous findings in IPF, in which a subset of patients with IPF also had high circulating fibrocyte levels, which was predictive for patients at risk for acute exacerbation and death.