Effects of HLA-matched blood transfusion for patients awaiting renal transplantation

HLA sensitization in potential renal transplant recipients hinders opportunities of receiving suitable organs. To alleviate this, we sought to determine if supplying closely HLA Class I matched leukodepleted blood would minimize sensitization.

Patients received HLA selected or random units of packed red cells. Selected units were sourced from blood donors included in the British Bone Marrow Registry and had no HLA-A and HLA-B mismatches where available, or alternatively, no HLA antigens with more than five immunogenic triplet mismatches as determined by the HLA-Matchmaker algorithm. Posttransfusion antibody screening confirmed development of de novo Class I and Class II HLA-specific IgG antibody(s) or increases in preexisting antibody levels of at least 20%.

Thirty-seven and 31 patients received HLA selected (mean, 2.5 units) and random (mean, 3.4 units) blood, respectively. A total of 20 of 37 (54.1%) patients receiving selected units and 10 of 31 (32.3%) patients receiving random units were previously sensitized. No patient receiving HLA selected units demonstrated any change in antibody levels. In patients who received random units, 7 of 31 demonstrated changes in antibody levels with three developing de novo HLA-specific antibodies and four an increase in panel reactive antibody (PRA) of at least 20% (P=0.002).

The risk of developing HLA-specific antibody is significantly reduced in renal patients awaiting transplantation when transfused with HLA selected units of blood compared with random units. With planning, access to HLA typed blood is achievable as many blood transfusion centers recruit donors for stem cell donor registries.