中文摘要：

肺纤维化是由多种病因引起的弥漫性肺部炎性疾病的共同结局。肺纤维化疾病包括特发性肺纤维化，结节病、尘肺、过敏性肺炎、药物和放射线导致的肺纤维化以及与胶原血管病有关的肺纤维化等。肺纤维化以大量成纤维细胞聚集、细胞外基质沉积并伴有炎症和损伤所致组织结构破坏为特征。其病理特点包括肺组织间质细胞增殖、细胞外基质增生沉积及肺实质重构，其发病率和病死率各不相同。目前大部分的研究认为肺成纤维细胞是促进细胞外基质沉积的主要细胞，然而最近的研究证实纤维细胞亦能够促进肺纤维化的演进。纤维细胞是骨髓来源的问叶祖细胞，是成纤维细胞、肌成纤维细胞及脂肪细胞的前体细胞，它能够表达与白细胞、单核巨噬细胞和成纤维细胞相关的细胞标记。本文将简单讨论纤维细胞在肺纤维化发病机制中的作用。

英文摘要：

Pulmonary fibrosis encompasses a heterogeneous group of disorders characterized by replacement of the lung parenchyma with scar tissue. Pulmonary fibrotic diseases include idiopathic pulmonary fibrosis, scleroderma, pneumoconiosis, hypersensitivity pneumonitis, drug and radiation- induced lung fibrosis and pulmonary fibrosis associated with collagen vascular disease. Pulmonary fibrosis is characterized by the gathering of a large number of fibroblasts, extracellular matrix deposition associated with inflammation and damage, and its pathological features include interstitial lung tissue cell proliferation, the hyperplasia and deposition of extracellular matrix, and pulmonary parenchyma remodeling. Although there are several cellular types that are involved in the pathogenesis of pulmonary fibrosis, the resident lung fibroblast has been viewed traditionally as the primary cell involved in promoting the deposition of extracellular matrix that culminates in pulmonary fibrosis. However, recent findings demonstrate that the fibrocyte can contribute to the evolution of pulmonary fibrosis. Fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of cell-surface markers related to leukocytes, hematopoietie progenitor cells, and fibroblasts. Fibrocytes are capable of differentiating into fibroblasts, myofibroblasts, and adipocytes. This article reviews the critical role of fibrocytes in the pathogenesis of pulmonary fibrosis.