Acute intravascular hemolytic anemia in the black rhinoceros: hematologic and immunohematologic observations.

To investigate the syndrome of acute intravascular hemolytic anemia in the black rhinoceros (Diceros bicornis), laboratory techniques used in the differential diagnosis of hemolytic anemias were performed on blood samples from 6 black rhinoceroses: 3 nonrelated healthy rhinoceroses, 1 rhinoceros with iron deficiency anemia, and 2 rhinoceroses with intravascular hemolysis. Osmotic fragility, erythrocyte membrane protein composition, hemoglobin electrophoresis, and hemoglobin stability did not distinguish between healthy and affected (anemia or hemolysis) rhinoceroses. Polyclonal antiglobulin reagents were prepared in rabbits, using whole rhinoceros serum and purified rhinoceros immunoglobulin G. These reagents were nonreactive against erythrocytes of the healthy and iron-deficient rhinoceroses. Reactions with RBC from the rhinoceros with fatal hemolytic anemia indicated increased membrane coating by the third component of complement; this was not evident in a second rhinoceros that survived a hemolytic event.

Clinically significant allo-anti-I in an I-negative patient with massive hemorrhage.

A 37-year-old white man who had never been transfused was admitted as an emergency patient with a ruptured spleen and a falling hematocrit (19% on admission). All crossmatches were incompatible. His serum contained anti-I, and his red cells (RBCs) were I-negative and strongly i-positive. Only 4 units of crossmatch-compatible I-negative frozen RBCs were available immediately. Because of the likelihood that more than 4 units would be required, chromium survival studies were performed using I-positive cells. Samples obtained at 15 and 30 minutes after injection revealed less than 1 percent survival of the donor RBCs. He received the 4 units of I-negative RBCs during the operation in addition to reinfusion of RBCs harvested from 1800 ml of blood aspirated from the abdominal cavity. The postoperative hematocrit remained greater than 30 percent and the bilirubin less than 1.5 mg per dl. Before recommending frozen storage of autologous RBCs, 51Cr labeled I-positive RBCs from the patient's daughter (obligate li heterozygote) were infused. Survival was 100 percent at 15 and 30 minutes, 90 percent at 3 hours, 85 percent at 26 hours; the remaining RBCs disappeared at a normal rate (T 1/2 27 days) over the succeeding 2 weeks. A repeat 51Cr-labeled RBC study with the original I-positive donor confirmed greater than 92 percent destruction in 90 minutes. The clinical significance of this allo-anti-l (apparently primarily against RBCs from homozygous I-positive donors) is in marked contrast to reported findings with auto-anti-l antibodies.

Long-term in vivo survival of Rh(D)-negative donor red cells in a patient with anti-LW.

The present study documents immediate and long-term survival of crossmatch-incompatible Rh(D)-negative donor red cells in a patient with anti-LW. A 67-year-old group A Rh(D)-positive man was admitted for urgent coronary artery bypass surgery. The direct antiglobulin test (DAT) was weakly positive in two of five laboratories. His serum contained anti-LW (two laboratories); his red cells were LW negative (three antisera). Two siblings were LW-positive. Surgery was delayed, and 3 ml Rh(D)-negative crossmatch-incompatible red cells stored in citrate-phosphate-dextrose-adenine-one were labeled with 25 microCi of 51Cr and injected. Immediate survival was approximately 100 percent with 92 percent survival at 20 hours. Six daily blood samples showed a decreased red cell lifespan, (T 1/2 = 14 days). Because of medical complications, 4 units of Rh(D)-negative crossmatch-incompatible blood were then transfused without clinical or hemolytic reaction. The anti-IgG DAT became stronger. In vivo survival of the remaining 51Cr-RBCs became normal (T 1/2 28 days over the succeeding 20 days). Following transfusion, no change in serum antibody strength was demonstrated by double-blind titration of seven coded samples. The observations support modest reduction of lifespan for 3 ml of LW-positive red cells, but normal survival following subsequent transfusion of approximately 700 ml of LW-positive red cells.