Acute Stem Cell Transplant Complications

The goal of this observation study is to test in patients undergoing allogeneic hemopoietic stem-cell transplantation (allo-HSCT). The main question it aims to answer is: • Effect of MAGIC algorithm probability guided preemption of aGVHD with ruxolitinib on prevention of severe aGVHD. Participants will take ruxolitinib with the dose of 5mg bid for 28 days. If no signs of aGvHD, the dose of ruxolitinib is gradually tapered within the following 16 days. Researchers will compare patients who don't receive preemption of aGVHD with ruxolitinib to see if there is an improvement in severe aGVHD.