Hemostatic disorders are common and potentially fatal complications in patients undergoing hematopoietic stem-cell transplantation (HSCT). Limited data exist on early diagnosis and prevention of these complications. The investigators undertook this prospective study to determine the incidence, predictor factors, specific pathogenesis, management and survival specially for patients with thrombotic and bleeding complication to better improve outcomes.

Hematopoietic stem cell transplantation（HSCT）is a curative treatment for a variety of malignant and refractory benign hematologic disease, but is associated with life-threatening complications in the same time, among them, hemostatic disorders are not uncommon and presenting an increasing morbidity and mortality in HSCT recipients. Bleeding and thrombosis, two of controversial disorders, have been posing a great threat to patients in the setting of transplantation, and early hemorrhagic complication after HCST is more frequent and subject to more concern by clinical physicians, previous studies have shown the risk of bleeding in HSCT recipients is more than 10-fold higher than neoplastic patients receiving chemotherapy. Meanwhile, thrombosis events, which is characterized by hepatic veno-occlusive diseases (HVOD), transplantation related thrombotic microangiopathy (TA-TMA), and venous thromboembolism (VTE) can not be imprudently ignored with its fatal threat to patients.

Over the last two decades, it has been recognized that the relatively increasing incidence of bleeding and thrombotic complications correlating to the prognosis and quality of life for HSCT recipients. Previous studies have shown that conventional risk factors including graft-versus-host disease (GVHD), infection, thrombocytopenia, the anticoagulation therapy, damage of endothelial cell and conditioning regimen can contribute to the onset of hemostatic disorders in HSCT recipients or can even exacerbate the process. Nevertheless, their roles and detailed pathogenesis in the development of bleeding and thrombosis remain undefined and limited data in Asian population was known about the competing risks of thrombosis and bleeding.

Given the current understanding of hemostatic complication and many unknown mechanisms of relation between thrombosis and hemostasis，we undertook this prospective study to determine the incidence, predictor factors, specific pathogenesis, and survival specially for patients with thrombotic and bleeding complication to better improve outcomes.

Inclusion Criteria:

• 1. Patients signed their informed consents are enrolled; 2. Patients suffering from hematological diseases and undergoing hematopoietic stem cell transplantation.

Exclusion Criteria:

• 1. Patients who have not signed their informed consents; 2. Patients with previous history of platelet disorder or bleeding diathesis; 3. Patients with inadequate renal function or hepatic function, or other essential organ damage.

The incidence and severity of hemostatic complications in patients following HSCT.