体外光化学疗法防治移植物抗宿主病机制研究进展

体外光化学疗法(extracorporeal photochemotherapy),又称体外光分离置换疗法(extracorporeal photopheresis,ECP),现已成为一种防治移植物抗宿主病(GVHD)的手段。一般认为,ECP防治GVHD的机制为诱导免疫耐受;进一步的研究发现,其作用于GVHD发生的多个阶段,主要机制包括以下几方面:①作用于T淋巴细胞,包括诱导T淋巴细胞凋亡,抑制效应性T细胞分化增殖,促进调节性T细胞增殖,调整辅助T细胞数目及比例;②作用于抗原呈递细胞,诱导其凋亡,抑制其分化成熟,并影响其加工递呈抗原的能力;③调节细胞因子分泌,抑制炎症反应。本文将从上述几个方面对ECP防治GVHD的机制进行综述。

Advances of Mechanism Study on Extracorporeal Photochemotherapy to Treat and Prevent Graft-Versus-Host Disease In Vitro-Review

Extracorporeal photochemotherapy,also called extracorporeal photopheresis,or ECP for short,is now an effective method to treat and prevent patients from graft-versus-host disease（GVHD）.It is generally accepted that the mechanism of ECP is to induce immune tolerance.Further researches show that ECP acts on several stages of GVHD by means of many complex mechanisms.Firstly,ECP induces apoptosis of T lymphocytes,inhibiting T cells from differentiating and proliferating,and promoting regulatory T cells.Besides,it also adjusts the number and proportion of helper T cells.Secondly,ECP affects antigen presenting cells.It induces apoptosis and inhibits maturation of antigen presenting cells.At the same time it affects the ability to process and present antigens of antigen presenting cells.Thirdly,ECP adjusts the cytokine secretion,in order to inhibit inflammatory response.This review discusses why ECP can treat and prevent patients from GVHD via the three aspects mentioned above.