Canine platelet alloimmunization: the role of donor selection

Abstract

Five different platelet transfusion programmes were evaluated in a canine model to determine the most effective method of providing long‐term platelet support. When a weekly transfusion from a single unrelated donor was used, alloimmune platelet refractoriness developed in 95% of recipients after an average of 3.1 ± 0.7 transfusions, and donor platelets circulated for a total of 8.2 ± 2.3 d. When multiple unrelated donors were used, the percentage of refractory recipients was similar (60% versus 77%) whether platelets came from six single donors given sequentially or from a pool of the same six donors given repeatedly. There was, however, a significant difference in the number of transfusions given prior to immunization (14 ± 5 transfusions lasting 32 ± 12 d for sequential single donors as compared to 5.5 ± 1.0 transfusions lasting 13 ± 2 d for the pooled donors).