An increasing number of older patients with acute myeloid leukemia (AML) are offered an allogeneic hematopoietic stem cell transplantation (allo-HSCT). Normally, older patients have older matched related donors (MRD). Matched unrelated donors (MUD) are an important alternative, but it remains unclear whether a younger MUD is associated with better outcomes, especially in the context of post-transplant cyclophosphamide (PTCy). We compared outcomes of patients older than 50 years with AML in first complete remission (CR1) and receiving a first HSCT from a 10/10 MUD aged younger than 40 years to those receiving a graft from a MRD aged older than 50 years, using PTCy and with well-known transplant conditioning intensity (TCI) score. A total of 345 consecutive patients were included and classified according to TCI score as low, intermediate, or high. On multivariable analysis in the TCI-intermediate/high group, MUD was associated with better graft-versus-host disease-free, relapse-free survival, lower non-relapse mortality and lower relapse incidence. For patients receiving a TCI-low regimen, outcomes are independent on the type of donor. In patients with AML in CR1, older than 50 years and receiving a TCI-intermediate/high conditioning regimen using PTCy, a MUD younger than 40 years is preferable over a MRD older than 50 years.

越来越多的老年急性髓系白血病 (AML) 患者接受同种异体造血干细胞移植 (allo-HSCT)。通常，老年患者有年龄较大的匹配相关捐赠者 (MRD)。匹配的无关供体 (MUD) 是一种重要的选择，但目前尚不清楚年轻的 MUD 是否与更好的结果相关，特别是在移植后环磷酰胺 (PTCy) 的情况下。我们使用 PTCy 比较了 50 岁以上 AML 首次完全缓解 (CR1) 并接受 40 岁以下 10/10 MUD 首次 HSCT 的患者与接受 50 岁以上 MRD 移植的患者的结果并具有众所周知的移植调节强度（TCI）评分。总共纳入了 345 名连续患者，并根据 TCI 评分分为低、中或高。在 TCI 中/高组的多变量分析中，MUD 与更好的无移植物抗宿主病、无复发生存、较低的非复发死亡率和较低的复发率相关。对于接受低 TCI 方案的患者，结果与捐赠者的类型无关。对于年龄超过 50 岁且接受使用 PTCy 的 TCI 中/高调理方案的 CR1 级 AML 患者，小于 40 岁的 MUD 优于大于 50 岁的 MRD。