摘要
Bloodborne fibrocytes are cells mobilized from the bone marrow, which express surface antigens commonly ascribed to hematopoietic progenitors and have phenotypic and functional characteristics similar to those of immature mesenchymal cells. They exhibit predominant proinflammatory or profibrotic activities at tissue sites, depending on the host＇s response to environmental insults and on the characteristics of the cell infiltrate and cytokine milieu. In patients with allergic asthma, fibrocytes egress from the bone marrow and are recruited into the airways after every allergen exposure and during viral infections. Recruited fibrocytes amplify the inflammatory responses driven by T helper type 2 lymphokines and favor viral replication and further inflammation on respiratory virus infections. Persistently elevated blood fibrocyte counts and persisting airway fibrocytosis are present in patients with chronically undertreated or corticosteroid-insensitive asthma, and are linked to an enhanced risk of adverse outcomes because of the major involvement of fibrocytes in the development of structural abnormalities that lead to chronic airflow obstruction in these patients. Consequently, blood fibrocyte count is an emerging biomarker of asthma control and disease progression and its clinical applicability as a new outcome measure deserves further evaluation in large clinical trials.
血源性成纤维细胞来自骨髓,可表达一些通常造血祖细胞属性的表面抗原,同时有和未成熟间质细胞相似的表型和功能特征。依据机体对环境刺激的反应和局部浸润的细胞类型及不同的细胞因子环境,血源性成纤维细胞可局部组织显示强烈的促炎症活性或促纤维化活性。过敏性哮喘患者每次遭受过敏原暴露或病毒感染时,成纤维细胞即从骨髓中迁出并被募集至气道组织;而募集的成纤维细胞可放大由Th2细胞因子驱使的炎症反应,并有利于病毒的复制,进一步加重病毒感染引发的炎症。在未治疗的慢性哮喘和激素不敏感的哮喘患者中可观察到持续性外周血成纤维细胞计数升高及气道纤维细胞浸润,而这和不良预后的风险增加有关。究其原因,成纤维细胞主要涉及气道结构异常的进展,而后者导致患者慢性气流受限。因此,外周血成纤维细胞计数是一种新发现的哮喘控制和疾病预后的生物学标记,作为一种新的结果检测方法,它的临床应用还需要大样本临床研究去评估。
