Recovery of Natural Interferon-α/β-producing Cells after Allogeneic Hematopoietic Stem Cell Transplantation

免疫系统恢复迟缓是移植后感染的主要原因。天然干扰素(IFN)-α/β-产生细胞（IPC）通过产生大量IFN-α/β并随后分化为树突状细胞，在诱导对多种微生物病原体的有效免疫应答中发挥关键作用。在这里，我们检测了28例异体造血干细胞移植（HSCT）后IPC和其他免疫细胞的恢复情况，以探讨IPC在移植后免疫重建中的作用。在不复杂的病例中，IPC频率在移植后30天内恢复到正常值的较低范围，类似于先天免疫中其他细胞类型的迅速恢复。相比之下，在急性GVHD和糖皮质激素治疗的情况下，IPC的恢复受到严重抑制。IPC数量较少的患者更容易发生病毒感染。在不复杂的病例中，IPC的迅速恢复可能有助于在同种异体造血干细胞移植后的早期阶段建立第一道宿主防线，而急性GVHD和糖皮质激素治疗对IPC恢复的明显抑制可能增加机会性感染的风险。

Delayed recovery of the immune system is a major cause of post-transplant infection. Natural interferon (IFN)-α/β-producing cells (IPC) appear to play a critical role in inducing effective immune responses to a variety of microbial pathogens by producing an enormous amount of IFN-α/β and thereafter by differentiating into dendritic cells. Here, we examined the recovery of IPC as well as other immune cells in 28 patients after allogeneic hematopoietic stem cell transplantation (HSCT) in order to investigate the role of IPC in post-transplant immune reconstitution. In uncomplicated cases, IPC frequency recovered to the lower range of normal values within 30 days after transplantation, resembling the prompt recovery of other cell types in innate immunity. In contrast, the recovery of IPC was profoundly suppressed in the cases with acute GVHD and glucocorticoid administration. The patients with lower numbers of IPC were significantly more susceptible to viral infection. The prompt recovery of IPC in uncomplicated cases may contribute to establishing a first line of host defense at the early stage after allogeneic HSCT, whereas the marked suppression of IPC recovery accompanying acute GVHD and glucocorticoid administration may increase the risk of opportunistic infections.