Low-dose decitabine for refractory thrombocytopenia following allogeneic hematopoietic stem cell transplantation in children: A pilot study

•Decitabine increased platelet count in thrombocytopenia after transplantation.•Decitabine was effective both for leukemia and non-hematologic malignancies.•Different doses of decitabine (3.5, 5 and 10 mg/m2) all presented efficacy.•The dose of decitabine should base on bone marrow condition and underlying diseases. Refractory thrombocytopenia is a critical complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT), which is not sensitive to conventional treatment and often leads to lower overall survival and disease-free survival. Previous studies have showed the efficacy and safety of low-dose decitabine for adults’ refractory prolonged isolated thrombocytopenia in hematologic malignancy after allo-HSCT. However, clinical data on pediatric patients or non-hematologic malignancies are lacking. Herein, we evaluated the safety and efficacy of low-dose decitabine in nine children with persistent thrombocytopenia after HSCT. Patients received decitabine at 3.5 mg/m2, 5 mg/m2 or 10 mg/m2 respectively for three to five consecutive days according to underlying diseases and hyperplastic state of bone marrow. Six patients reached sustained platelets count more than 100 × 109/L, two patients achieved platelet transfusion independence. The total response rate was 88.8 % (8/9). One patient died from severe infection because of persistent agranulocytosis longer than 3 weeks. In conclusion, the present study supports the safety and efficacy of low-dose decitabine for treatment of refractory thrombocytopenia after allogeneic HSCT in children.