异基因造血干细胞移植（HSCT）的治疗基础部分依赖于移植物抗白血病（GvL）效应，即供体免疫细胞识别并消除受体恶性细胞。然而，供体细胞对受体组织的同种异体反应性也可能是有害的。慢性移植物抗宿主病 (cGvHD) 是一种免疫现象，其中同种异体反应性供体 T 细胞对宿主组织发生异常反应，导致破坏性炎症症状。在这里，我们讨论对 GvL 和 cGvHD 的生物学见解，以及平衡预防 GvHD 与维持 GvL 的策略。现代 HSCT。复发仍然是 HSCT 后死亡的主要原因，某些疾病的复发率高达 40%。 GvHD 是 HSCT 后发病的主要原因，发生在多达一半的患者中，并导致 HSCT 后 15-20% 的死亡。有趣的是，慢性 GvHD 的发展可能与 HSCT 后较低的复发率有关，这表明 GvL 和 GvHD 可能是 HSCT 免疫学基础的互补方面。微调 GvL 和 GvHD 平衡的能力将改善接受 HSCT 患者的生存率、复发率和生活质量。

The curative basis of allogeneic hematopoietic stem cell transplantation (HSCT) relies in part upon the graft versus leukemia (GvL) effect, whereby donor immune cells recognize and eliminate recipient malignant cells. However, alloreactivity of donor cells against recipient tissues may also be deleterious. Chronic graft versus host disease (cGvHD) is an immunologic phenomenon wherein alloreactive donor T cells aberrantly react against host tissues, leading to damaging inflammatory symptoms.Here we discuss biological insights into GvL and cGvHD and strategies to balance prevention of GvHD with maintenance of GvL in modern HSCT.Relapse remains the leading cause of mortality after HSCT with rates as high as 40% for some diseases. GvHD is a major cause of morbidity after HSCT, occurring in up to half of patients and responsible for 15-20% of deaths after HSCT. Intriguingly, development of chronic GvHD may be linked to lower relapse rates after HSCT, suggesting that GvL and GvHD may be complementary sides of the immunologic foundation of HSCT. The ability to fine tune the balance of GvL and GvHD will lead to improvements in survival, relapse rates, and quality of life for patients undergoing HSCT.