Recombinant human thrombopoietin improves platelet engraftment after autologous hematopoietic stem cell transplantation in patients with aggressive lymphoma

High-dose chemotherapy (HDT) followed by autologous hematopoietic stem cell transplantation (ASCT), recommended as consolidation therapy for high-risk lymphoma, or salvage therapy for relapsed/refractory lymphoma, has shown survival benefits for patients [1-3]. However, the complications of transplant-related infection and bleeding as well as disease recurrence and progression, remain serious clinical problems to be solved. The median time to platelet engraftment after ASCT ranges from 9 to 38 days [4]. Prolonged platelet engraftment increases the risk of bleeding events, even life-threatening, and also leads to platelet transfusion dependence or resistance accompanied by the increasing incidence of transfusion side effects [5]. All of the above results in prolonged hospital stay, increased medical cost and decreased quality of life for patients [6-8]. However, there is no effective therapeutic strategy to promote platelet engraftment after ASCT. Thrombopoietin (TPO), as a hematopoietic growth factor, could promote thrombopoiesis by stimulating the differentiation of hematopoietic stem cells into megakaryocytes and the proliferation and maturation of megakaryocytes [9-12]. Recombinant human TPO (rhTPO), which retains the amino acid sequence identical to endogenous TPO, has been widely used in chemotherapy-induced thrombocytopenia, immune thrombocytopenia [13, 14] and aplastic anemia (AA) [15]. The safety of rhTPO has been established for decades in previous studies [16, 17] for decades. Recent studies in allogeneic hematopoietic stem cell transplantation (allo-HSCT) demonstrated that rhTPO could promote platelet engraftment and reduce platelet transfusion [18, 19], and even significantly improve the prognosis of patients with myelodysplastic syndrome (MDS) and AA [20]. And rhTPO was also found to accelerate platelet engraftment after ASCT in patients with multiple myeloma, especially for those with poor CD34 + cell counts [21]. Our present study evaluated the efficacy and safety of rhTPO after ASCT in patients with malignant lymphoma.