Pulmonary dendritic cell accumulation in usual interstitial pneumonia and nonspecific interstitial pneumonia.

BACKGROUND: Pulmonary dendritic cells (DCs) are key regulators of immune responses. An increased accumulation of DCs was reported in the lungs of patients with idiopathic interstitial pneumonia (IIP). OBJECTIVE: This study aimed to investigate the number of pulmonary DCs in patients with collagen vascular disease associated interstitial lung diseases (CVD-ILDs). DESIGN: Lung tissue samples obtained from 27 patients with IIP and 39 patients with CVD-ILD were detected using monoclonal antibodies against CD1a, CD1c, CD83, Langerin and DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN). RESULTS: No significant differences in the number or distribution of DCs were observed between patients with IIP and CVD-ILDs. When DC marker expression was analyzed according to pathological subgroup, patients with idiopathic usual interstitial pneumonia (UIP) showed increased DC-SIGN staining when compared with CVD-UIP (p < 0.05). CONCLUSION: Both mature and immature DCs accumulate in CVD-ILDs. The number of DCs expressing DC-SIGN in CVD-UIP was decreased compared with that in idiopathic UIP. The variation in accumulated DC-SIGN-positive cells might help to explain the differences in the development and maintenance of lung inflammation between idiopathic UIP and CVD-UIP.