Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective or even the only way to cure blood malignant diseases. Cytomegalovirus (CMV) infection is a serious early complication of allo-HSCT. Its high incidence and poor prognosis can cause a series of terminal organ diseases such as CMV pneumonia, encephalitis, and enteritis,which seriously affecting the prognosis of patients post allo-HSCT.

Our data show that rapid reconstruction of NK cells after transplantation can reduce the incidence of CMV infection. Patients with a rapid reconstruction of NKG2C after transplantation have a low CMV infection rate, and patients with strong secretion of IFN-gamma of NK after transplantation have low CMV infection.

Our previous research showed that trophoblast cells transfected with IL-21 and 4-1BBL can achieve a large number of clinical-grade expansion of NK cells (mIL-21 / 4-1BBL NK cells), and mIL-21 / 4-1BBL NK cells It is safe to treat patients with minimal residual disease (MRD) positive AML after transplantation, and can induce MRD to turn negative. Previous studies have shown that adoptive infusion of expanded NK cells after haplotype transplantation is safe and can improve the functional reconstruction of NK cells. Therefore, we hypothesized that the infusion of NK cells can improve the antiviral capacity of NK cells, thereby effectively reducing the CMV infection. Incidence.

Inclusion Criteria:

1. Patients with acute leukemia (AL) or myelodysplastic syndrome (MDS) or myeloma or lymphoma undergoing haploidentical allogeneic stem cell transplantation
2. No CMV infection by 20 days ± 3 days after transplantation
3. No active acute GVHD by 20 days ± 3 days after transplantation
4. The dose of prednisolone was less than 0.5mg / kg / d within 72 hours before and after infusion of NK cells
5. Prior to transplantation, the CMV IgG of the recipient and donor were positive, and the recipient had a suitable donor to expand NK cells.
6. Patient age 16-65 years
7. Donor age 16-65 years
8. Patient Karnofsky score> 70%
9. Estimated survival> 3 weeks
10. Patient agrees to participate in study

Exclusion Criteria:

1. Participants in any other clinical trials within 1 month before enrollment
2. Active infection
3. HBV or HCV or HIV carriers
4. With moderate to severe renal dysfunction (blood creatinine> 130umol / L) and / or liver dysfunction (total bilirubin> 34umol / L, ALT, AST> 2 times the upper limit of normal) before NK infusion
5. Researchers do not consider it appropriate to participate in this trial.