Nicolls Mark R, Hsu Joe L, Jiang Xinguo
VA Palo Alto Healthcare System, Stanford University School of Medicine, Stanford, California, USA.
Curr Opin Organ Transplant. 2016 Jun;21(3):279-84. doi: 10.1097/MOT.0000000000000307.
Airway microvessel injury following transplantation has been implicated in the development of chronic rejection. This review focuses on the most recent developments in the field describing preclinical and clinical findings that further implicate the loss of microvascular integrity as an important pathological event in the evolution of irreversible fibrotic remodeling.
When lungs are transplanted, the airways appear vulnerable from the perspective of perfusion. Two vascular systems are lost, the bronchial artery and the lymphatic circulations, and the remaining vasculature in the airways expresses donor antigens susceptible to alloimmune-mediated injury via innate and adaptive immune mechanisms. Preclinical studies indicate the importance of hypoxia-inducible factor-1α in mediating microvascular repair and that hypoxia-inducible factor-1α can be upregulated to bolster endogenous repair.
Airway microvascular injury is a feature of lung transplantation that limits short-term and long-term organ health. Although some problems are attributable to a missing bronchial artery circulation, another significant issue involves alloimmune-mediated injury to transplant airway microvessels. For a variety of reasons, bronchial artery revascularization surgery at the time of transplantation has not been widely adopted, and the current best hope for this era may be new medical approaches that offer protection against immune-mediated vascular injury or that promote microvascular repair.
移植后气道微血管损伤与慢性排斥反应的发生有关。本综述重点关注该领域的最新进展，描述临床前和临床研究结果，这些结果进一步表明微血管完整性的丧失是不可逆纤维化重塑过程中的一个重要病理事件。
肺移植时，从灌注角度来看气道似乎很脆弱。两个血管系统丧失，即支气管动脉和淋巴循环，气道中剩余的脉管系统表达的供体抗原易受先天和适应性免疫机制介导的同种免疫损伤。临床前研究表明缺氧诱导因子-1α在介导微血管修复中具有重要作用，并且缺氧诱导因子-1α可被上调以增强内源性修复。
气道微血管损伤是肺移植的一个特征，会限制器官的短期和长期健康。虽然一些问题可归因于支气管动脉循环缺失，但另一个重要问题涉及同种免疫介导的对移植气道微血管的损伤。由于多种原因，移植时的支气管动脉血运重建手术尚未广泛应用，这个时代目前最大的希望可能是新的医学方法，这些方法能够预防免疫介导的血管损伤或促进微血管修复。
