Comprehensive management of hematopoietic stem cell transplantation complications: from infection prevention to immune microenvironment reconstruction

This article systematically reviews the management of key complications in hematopoietic stem cell transplantation (HSCT), including infections, graft-versus-host disease (GVHD), and hepatic sinusoidal obstruction syndrome (VOD/SOS). It highlights the importance of optimizing conditioning regimens to reduce infection risk and discusses the role of novel antiviral agents like letermovir in transforming infection control. For GVHD, the pathogenesis involving effector and regulatory T-cell imbalances is analyzed, together with prevention strategies such as post-transplant cyclophosphamide with antithymocyte globulin and TCRαβ/CD19 depletion. Ruxolitinib is emphasized for steroid-refractory GVHD, and gut microbiota modulation is noted as a promising intervention. For VOD/SOS, early biomarker detection and defibrotide treatment are critical. The review also explores the impact of immune reconstitution on infection control, GVHD development, and relapse, and examines how emerging approaches, including single-cell sequencing, microbiome analysis, and artificial intelligence, can be applied in building whole-course risk management models. Future directions include developing intelligent platforms and personalized strategies to enhance long-term patient outcomes.