The Safety and Efficacy of Umbilical Cord Blood Mononuclear Cells in Patients With Secondary Poor Graft Function After Hematopoietic Stem Cell Transplantation

Inclusion Criteria:

1. Age≥18 years old; gender is not limited.

2. Meet the diagnostic criteria for secondary poor graft function: After 28 days oftransplantation, patients who had achieved hematopoietic reestablishment (ANC ≥ 0.5×10^9/L for 3 consecutive days without G-CSF application, PLT ≥ 20×10^9/L for 7consecutive days without platelet infusion, Hb ≥ 80g/L for 2 consecutive weekswithout red blood cell infusion) again developed two or three line cytopenia lastingmore than 2 weeks. Bone marrow examination revealed low myelodysplasia, remission ofprimary disease, complete donor chimeric cells, and no severe graft-versus-hostdisease (GVHD) or disease recurrence.

3. Eastern Cooperative Oncology Group (ECOG) physical status score ≤ 2 points.

4. Subjects sign informed consent.

Exclusion Criteria:

1. Serious infection not controlled.

2. Active bleeding.

3. Patients with cardiac insufficiency (ejection fraction<50%), or suffering fromserious heart disease, including myocardial infarction, cardiac insufficiency, etc.

4. Patients with hepatic and renal insufficiency (total bilirubin>35µmol/L, ALT andAST>2 times of the upper limit of normal; serum creatinine>130µmol/L).

5. Pregnant or lactating women.

6. Concurrent malignant tumors of other organs.

7. Failure to understand or follow the research protocol.

8. Patients participating in other clinical investigations.

9. Other conditions that the investigators consider inappropriate to participate in thestudy.