Blood product support for stem cell transplantation

All cellular blood products, i.e. red cells and platelets, must be irradiated. Irradiation

• All cellular blood products given to allogeneic and autologous SCT patients must be irradiated to prevent transfusion associated GvHD due to transfused T lymphocytes.

• Transfusion associated GvHD is usually fatal particularly in allografts.

• Fatality can sometimes be avoided by immediate administration of antilymphocyte globulin or Campath antibody.

• Irradiation protocol is standard 2500cGy.

• Commence blood product irradiation two weeks prior to allogeneic SCT until one year post-SCT or off all immunosuppression whichever is later.

• Commence blood product irradiation two weeks prior to autologous SCT until six months post-SCT.

• Cell-free blood products e.g. FFP, cryoprecipitate or albumin do not need to be irradiated.

• Marrow or blood stem cell transplant itself is never irradiated.

CMV status of blood products

• CMV is not destroyed by irradiation.

• All transplant recipients should ideally receive CMV -ve red cells and platelet transfusions regardless of their own CMV status if sufficient CMV -ve blood products available. This is because of good evidence that transfused CMV carried in donor white cells may cause disease post-transplant regardless of the CMV status of the patient. CMV -ve recipients must always have -ve products.

• Should CMV negative platelets not be available at any time, it is acceptable to use unscreened leucodepleted red cells or platelets. This is because CMV is carried predominantly in leucocytes.

• For allograft recipients, additional preventive measures are taken against CMV reactivation (see p334).

Indications for RBC and platelet transfusions

Identical to those for patients undergoing intensive chemotherapy (see, pp546-650).

Management of ABO incompatibility

ABO incompatibility between donor and recipient does not affect the long-term success of the transplant nor the incidence of graft failure or GvHD. However, major ABO incompatibility transfusion reactions will occur unless specific steps are taken to manipulate the graft where donor and recipient are ABO mismatched. Furthermore, additional care must be given post-transplant in providing appropriate ABO matched products.

ABO mismatched definitions

1. Major ABO mismatch. This is where the recipient has anti-A or anti-B antibody to donor ABO antigens e.g. group O recipients with group A donor.

2. Minor ABO mismatch. This is where the donor has antibodies to recipient ABO antigens e.g. group A recipient with group O donor.

Management of major ABO mismatch

Manipulation of donor marrow/stem cells: red cells are removed in the transplant laboratory by starch sedimentation or Ficoll centrifugation, prior to infusion of the graft.

Choice of red cell and platelet supportive transfusions

• Transfuse packed group O red cells only for all major mismatch donor-recipient pairs.

• The choice of platelet group is less critical and may be affected by availability. First, second and third choice groups for platelet transfusions are shown in the table below.

Management of minor ABO mismatch

Manipulation of donor stem cells: prior to infusion, the product will have been plasma reduced in the transplant laboratory by centrifugation to remove antibody that could be passively transferred. Delayed immune haemolysis, which may be severe and intravascular, can occur after minor ABO mismatch due to active production of antibody by engrafting donor lymphocytes. Maximum haemolysis occurs 9-16 days post-transplant.

Choice of red cell and platelet transfusions

• Always transfuse packed O red cells, i.e. the same as in major ABO mismatch.

• Platelet transfusions first, second and third choice group is shown in the table below.

0 0

Post a comment