Info

🌱 來自: Huppert’s Notes

Stem Cell Transplant Basics

Types of hematopoietic stem cells (HSCs):

Autologous:

• own HSCs to “rescue” the bone marrow after high intensity chemotherapy
• Uses: Multiple myeloma, some lymphomas, germ cell tumors

Allogeneic:

• donor (non-self) HSCs to replace the bone marrow after high-intensity chemotherapy AND for graft vs. tumor effect
• Uses: AML, ALL, CML, CLL

Sources of cells:

Peripheral blood stem cells:

The donor is given a growth factor (e.g., G-CSF, GM-CSF) to mobilize HSCs from the bone marrow and then peripheral blood is collected. Less invasive, lower risk for the donor.

-   Bone marrow: Bone marrow aspirated from the iliac crests

-   Umbilical cord: Umbilical cord blood has a high number of HSCs. However, there is only a limited amount of blood if engraftment fails.

*   Matching for allogeneic transplant:

-   For allogeneic transplants, where non-self cells are given to a patient, donors are tested by HLA matching. There are 12 HLA alleles that are tested with a “12/12” match being the best match.

-   Potential donors:

*****   Identical twin: Ideal source as they will be a 12/12 match in addition to matching on other alleles and antigens not tested

*****   Matched related donor (MRD): Ideally a sibling

*****   Matched unrelated donor (MURD)

*   Side effects: For autologous and identical twin allogeneic transplants, will not develop GVT or GVHD

-   Graft vs. tumor: Desired therapeutic side effect where the transplanted T-cells recognize the tumor cells as foreign and immunologically attack the tumor cells

-   Graft vs. host disease (GVHD): Undesired side effect where the transplanted T-cells attack the host’s cells, causing an autoimmune syndrome. Most common sites: Skin, liver, GI tract.

*****   Acute: Within 100 days of transplant

*****   Chronic: >3 months after transplant, but can occur at any time

*****   Prophylaxis: Patients receive immunosuppressive medicines to prevent graft rejection and prevent GVHD, such as tacrolimus, sirolimus, mycophenolate, methotrexate, post-transplant cyclophosphamide

*****   Treatment: Depends on the timing and severity of GVHD. Treatment usually includes increasing immunosuppressive regimens and steroids.