Donor Selection

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Table 25-6 lists the blood bank support necessary for bone marrow transplantation.

Any HLA-identical sibling should be considered as a donor. ABO mismatch is not a contraindication, but if multiple donors are available, donors with the same ABO type should be used. Major ABO mismatch (A or B in O) requires removal of the red cells and plasma from the marrow prior to infusion. The HLA match can be

Table 25-6. Blood Bank Support in Bone Marrow Transplantation

Problem

Solution

Transfusion-associated graft versus host disease

CMV transmission (CMV-negative donor and recipient)

Alloimmunization

1. Graft failure or rejection (especially aplastic anemia)

2. Refractory thrombocytopenia"

ABO incompatibility

1. Major

Patient O, donor A-IHT >1:16 Patient O, donor B-IHT >1:16

2. Minor

Patient A, donor O-IHT >1:128 Patient B, donor O-IHT >1:128 Donor red cell transfusion requirements

Standard: gamma radiation (2500-3000 cGy) Investigational:

a. Leukocyte depletion b. Selective T-cell depletion c. Ultraviolet radiation

Standard: use of only CMV-negative blood products through an in-line filter to remove lymphocytes and leukocytes that may harbor latent viruses Alternative: leukocyte-depleted blood products

Avoidance or minimizing of pretransplant transfusions; avoidance of transfusions from family members, especially potential donors Most effective: leukocyte-depleted blood products a. Single-donor platelets b. Ultraviolet irradiation c. HLA-matched donors d. Cross-matched platelets

Removal of red blood cells from donor marrow

Removal of plasma from donor marrow

Autologous red blood cell salvage Predeposition of autologous red blood cell units

Abbreviations: CMV, cytomegalovirus; IHT, isohemagglutinin titer.

From Rowe JM, et al. Recommended guidelines for the management of autologous and allogeneic bone marrow transplantation: a report from the Eastern Cooperative Oncology Group ECOG. Ann Int Med 1994;120:143-58, with permission.

aNonalloimmunization causes of refractory thrombocytopenia include drugs, hepatic veno-occlusive disease, hypersplenism, or sepsis. Another more unusual cause of refractory thrombocytopenia is a syndrome resembling thrombotic thrombocytopenic purpura, often associated with the use of cyclosporine, total body irradiation, or the development of acute GVHD.

phenotypic or genotypic. Finding the right donor necessitates matching of HLA antigens or histocompatibility genes by serology or molecular methodology. The major histocompatibility complex (MHC) is divided into two groups. The class I molecules are HLA-A, HLA-B, and HLA-C and the class II molecules are HLA-DR, HLA-DQ, and HLA-DP. Currently, matching is generally confined to major class I and II loci. However, it is increasingly appreciated that minor histocompatibility antigens are also likely to play important roles in the outcome of allogeneic HSCT. One of the major obstacles in allogeneic HSCT is that 60-70% of patients have no acceptable donors within their families. In these cases, volunteer unrelated or related donors who are HLA, A, B, and DR compatible with the recipients may be available as bone marrow donors worldwide through the U.S. National Marrow Donor Program (NMDP). Partial HLA-matched donors are sometimes used. Immunosuppressive drugs are given after transplantation to inhibit or modify the graft versus host immune reaction.

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