From the Cedars-Sinai Medical Center, Women's Guild Lung Institute, 127 San Vicente Blvd, Los Angeles, CA 90048, USA.
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cedars-Sinai Medical, Center, 8700 Beverly Blvd, Los Angeles, CA 90048, USA.
QJM. 2023 Jul 28;116(7):487-492. doi: 10.1093/qjmed/hcac206.
Pulmonary fibrosis is a sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection that currently lacks effective preventative or therapeutic measures. Post-viral lung fibrosis due to SARS-CoV-2 has been shown to be progressive on selected patients using imaging studies. Persistent infiltration of macrophages and monocytes, a main feature of SARS-CoV-2 pulmonary fibrosis, and long-lived circulating inflammatory monocytes might be driving factors promoting the profibrotic milieu in the lung. The upstream signal(s) that regulates the presence of these immune cells (despite complete viral clearance) remains to be explored. Current data indicate that much of the stimulating signals are localized in the lungs. However, an ongoing low-grade systemic inflammation in long Coronavirus Disease 2019 (COVID-19) symptoms suggests that certain non-pulmonary regulators such as epigenetic changes in hematopoietic stem cells might be critical to the chronic inflammatory response. Since nearly one-third of the world population have been infected, a timely understanding of the underlying pathogenesis leading to tissue remodeling is required. Herein, we review the potential pathogenic mechanisms driving lung fibrosis following SARS-CoV-2 infection based upon available studies and our preliminary findings (Graphical abstract).
肺纤维化是严重急性呼吸综合征冠状病毒 2(SARS-CoV-2)感染的后遗症,目前缺乏有效的预防或治疗措施。使用影像学研究已经表明,某些患者的 SARS-CoV-2 病毒性肺纤维化是进行性的。持续性的巨噬细胞和单核细胞浸润,这是 SARS-CoV-2 肺纤维化的主要特征,以及长寿的循环炎症性单核细胞可能是促进肺中致纤维化微环境的驱动因素。调节这些免疫细胞存在的上游信号(尽管病毒已完全清除)仍有待探索。目前的数据表明,大部分刺激信号都局限在肺部。然而,在长期的 2019 年冠状病毒病(COVID-19)症状中持续存在低度全身炎症表明,某些非肺调节因子,如造血干细胞中的表观遗传变化,可能对慢性炎症反应至关重要。由于世界上近三分之一的人口已经感染,因此需要及时了解导致组织重塑的潜在发病机制。在此,我们根据现有研究和我们的初步发现,综述了 SARS-CoV-2 感染后导致肺纤维化的潜在发病机制(示意图)。