Biomedical cell biology: Stem cell transplantation

transplants: bone marrow, cord blood, peripheral blood stem cell transplants (PBSC)

from identical twin (syngeneic)

from donor (allogenic)

from patients own cells (autologus)

collection:

bone marrow: 500-1200l are harvested from pelvis

umbilical cord: donated at birth 

peripheral blood: collected using cell separator to concentrate stem cells

PROCESSING:

• mononuclear cells concentrated
• red cells removed
• in autologus transplants; malignant cell removed by antibodies of chemo
• allogeneic transplants t-cells removed prevent GVHD (graft verse host disease)
• enrich for CD34+ cells

CONDITIONING:

• chemotherapy with total body irradation to irradicate patients haemopoietic system (create space for new marrow eliminate disease)
• myeloablative
• non-myeloablative - mini transplant

POST TRANSPLANT ENGRAFTMENT:

• severe pancytopenia (condition where there is a reduction in the number of red/ white cells and platelets) for 1-3weeks; monocytes and neutrophils appear followed by an increase in platelet. reticulocytosis and NK cells also make an early appearance.
• Immune recovery is slow with low CD4 cells and raised CD8:CD4 ratio - bona marrow reserve remains impaired for up to two years

STEM CELL TRANSPLANTATION:

allogeneic: aute leukaemia, chronic myeloid leukaemia, other malignancies…