Massive sequestration of human sickle cells after transfusion to a baboon.

A baboon was exchange-transfused with sickle cell anemia patients' blood. The animal died suddenly, and postmortem examination showed widespread red cell sequestration, particularly in the spleen and liver. The clinical and pathological findings were similar to those in children with sickle cell anemia who die of acute splenic sequestration syndrome. A control animal, exchange-transfused with normal human blood, tolerated the procedure without difficulties for a period of 4 days, when a delayed transfusion reaction occurred. Thus the baboon can be used as a model for the abnormal circulatory behavior of sickle cells and for the sickle cell sequestration syndrome.