CD45RA Depleted Peripheral Stem Cell Addback for Viral or Fungal Infections Post TCRαβ/CD19 Depleted HSCT
CD45RA Depleted Peripheral Stem Cell Addback for Viral or Fungal Infections Post TCRαβ/CD19 Depleted HSCT
The major morbidities of allogeneic hematopoietic stem cell transplant with non-human
 leukocyte antigen (HLA) matched siblings are graft vs host disease (GVHD) and life
 threatening infections. T depletion of the donor hematopoietic stem cell graft is effective
 in preventing GVHD, but immune reconstitution is slow, increasing the risk of infections. An
 addback of donor CD45RA (naive T cells) depleted cells may improve immune reconstitution and
 help decrease the risk of infections.
The risk of severe graft versus host disease (GVHD) is increased with the use of unrelated
 and partially matched related donors. T cell depletion reduces the risk of severe GVHD, but
 immune reconstitution is delayed. Important memory T cells that may protect patients from
 fungal and viral infections are also removed in the T depletion process. CD45RA depletion has
 been studied both as a single step to reduce the risk of GVHD, and also, in conjunction with
 αβTCR depleted hematopoietic stem cell grafts to accelerate immune reconstitution. This is a
 single institutional pilot trial of this T cell depletion technique. Patients with acute
 leukemias at high risk for relapse are eligible to participate. Patients will be given CD45RA
 depleted donor peripheral stem cells (PSCs) following T depleted hematopoietic stem cell
 transplant (HSCT). A short course of GVHD prophylaxis will be used after CD45RA depletion.
Inclusion Criteria:

 1. Age: Patients <25 years.

 2. First allogeneic HSCT only.

 3. Disease eligibility: Acute leukemias at high risk for relapse including positive
 minimal residual disease at end consolidation, high risk cytogenetics, or relapse.
 Hematologic malignancies including: acute myeloid leukemia, myelodysplastic syndromes,
 acute lymphoblastic leukemia, mixed lineage or bi-phenotypic leukemia, lymphoblastic
 or Burkitts, juvenile myelomonocytic leukemia

 4. Evaluation of organ and infectious status as per our Bone Marrow Transplant standard
 operating procedure (BMT SOP).

 5. Signed consent by parent/guardian or able to give consent if >18 years.

 Exclusion Criteria:

 1. Patients who do not meet institutional disease, organ or infectious criteria

 2. No suitable donor available for mobilized peripheral stem cells

 3. Patients with genetic disorders including Fanconi anemia, Kostmann syndrome,
 dyskeratosis congenital or other DNA repair defects.

 4. Patients with Hodgkin lymphoma or non-Burkitts, non-lymphoblastic lymphoma

 Donor selection and eligibility

 1. Unrelated donor meets National Marrow Donor Program criteria for donation

 2. HLA testing/matching

 3. Donor must be willing to undergo granulocyte colony stimulating factor (GCSF)
 mobilization and peripheral blood stem cell collection