The multicenter collaborative clinical study conducted a systematic clinical observation in the treatment of bone marrow failure diseases via UCB&UC-MSCs , in order to observe its clinical efficacy and safety.

Inclusion Criteria:

1. Patients with bone marrow failure disorders, including aplastic anemia, pure red cell aplastic anemia, immune-related pancytopenia, paroxysmal nocturnal hemoglobinuria, myelodysplastic syndrome, acute arrest of hemopoiesis, and cytopenia of unknown significance;
2. Patients with no severe impairment of liver and kidney function (total bilirubin (TBIL): ≤ 1.5×ULN; ALT or AST: ≤ 2.5×ULN; Alkaline phosphatase: ≤ 3×ULN; Serum creatinine: ≤ 1.5×ULN);
3. The prothrombin time (PT) or activated partial thrombin time (APTT) or international normalized ratio (INR): ≤ 1.5×ULN in the absence of anticoagulant therapy;
4. The left ventricular ejection fraction (LVEF): ≥50% by cardiac echocardiography
5. Hepatitis B surface antigen (HBsAg) and Hepatitis B core antibody (HBcAb) were negative. If any of the above items is positive, the HBV DNA titer in peripheral blood must be lower than the detection limit or 1×10^3 copys/ml;
6. Patients with no plans for stem cell transplantation;
7. Patients with ECOG 0-2;
8. Those who voluntarily participate in this clinical study and have signed an informed consent .

Exclusion Criteria:

1. Patients who have suffered malignant tumors other than squamous cell carcinoma of the skin, basal cell carcinoma of the skin, malignant melanoma cured by surgery, and carcinoma in situ of the cervix in the past 5 years;
2. Patient with severe cardiac insufficiency (e.g. grade Ⅲ、Ⅳ by NYHA classification NYHA), and medically uncontrolled hypertension (systolic blood pressure ≥ 160 mmHg or diastolic blood pressure ≥110 mmHg);
3. Patients with severe mental illness;
4. Patients with clinically significant infection should be recruited with delay;
5. AST or ALT: above 3 times the upper limit of normal, creatinine, total bilirubin, or alkaline: phosphatase (ALP): above 1.5 times the upper limit of normal;
6. Patients with test positive for HIV, HCV or syphilis;
7. Patients with severe allergies or allergic to the active ingredients, excipients of the drug, or blood products in this clinical trials;
8. Patients who are pregnant or breastfeeding, or have a childbirth plan in the near future;
9. Patients receive allogeneic/autologous hematopoietic stem cell transplantation by the assessment of investigators;
10. There are other conditions that the investigators consider inappropriate for inclusion.