[Recent advances in the understanding of the pathophysiology of graft-versus-host disease]

Graft-versus-host disease (GVHD), which is characterized by T-cell activation following allogeneic hematopoietic cell transplantation (allo-HCT), remains one of the most significant hurdles directly or indirectly affecting transplant outcomes. With improved knowledge, experimental and clinical models have been established over the last two decades to predict the clinical utility of novel therapeutic agents, and clinical care has progressed. In addition, recent advances have revealed mechanisms underlying GVHD that focus on the breakdown of tissue tolerance following allo-HCT, complementing established concepts of immunological intolerance that allo-reactive T cells and antigen-presenting cells contribute to the development and aggravation of GVHD. The pathophysiology of GVHD as influenced by various cells and tissues and therapeutic strategies based on mechanistic findings to advance the understanding of GVHD and individualize allo-HCT have been discussed in this review.