HEMOLYTIC TRANSFUSION REACTIONS IN A DOG WITH AN ALLOANTIBODY TO A COMMON ANTIGEN

Alloantibodies to high-frequency red cell antigens, defined as inherit ed traits occurring in 92% to 99% or more of the general population, a re recognized as a cause of hemolytic transfusion reactions in humans, Here we describe a dog (dog erythrocyte antigen [DEA] 1.2- and DEA 4- positive) sensitized by prior blood transfusion, for which a compatibl e blood donor could not be found; transfusion of DEA 1.1-negative bloo d resulted in hemolytic transfusion reactions. Patient serum from days 1 (before first transfusion) and 16 was available for further testing : using 4 dogs with different blood types as potential donors, the maj or crossmatches were compatible using serum from day 1. However the cr ossmatches were all incompatible with serum from day 16, indicating th at the patient was sensitized to an antigen after the first transfusio n. The presence of an alloantibody against DEA 1.1 was not ruled out i n this patient, but the incompatibility reactions of patient serum wit h red cells from donors negative for DEA 1.1 indicated that an alloant ibody against a red cell antigen other than DEA 1.1 or any other known DEA for which typing reagents were available (DEA 3, 5, and 7) was pr esent. Subsequently, red cells from 1 of the patient's siblings (DEA 1 .2-, 4-, and 7-positive) were found not to agglutinate when incubated with patient's serum from day 16, ruling out the presence of an anti-D EA 7 antibody, and suggesting that an alloantibody against a common re d cell antigen missing in the patient and sibling was responsible for the blood incompatibility reactions. Failure to obtain a compatible cr ossmatch with several universal donors in a dog previously transfused should raise a suspicion that an alloantibody to a common red cell ant igen may exist and that a sibling may be a source of compatible blood.