Unexpected hemoglobin electrophoresis results following red cell exchange in a sickle cell anemia patient with acute chest syndrome.

Acute chest syndrome is a well described complication of sickle cell anemia. It is characterized by fever, pulmonary infiltrates, pleuritic chest pain and abnormal pulmonary auscultation. Transfusion therapy, either simple transfusion of red blood cells or a total red blood cell exchange, is a cornerstone therapy for these patients. Exchange transfusion is preferred when an acute reduction of the hemoglobin S (HbS) concentration is the therapeutic goal since it allows one to rapidly reduce the percent HbS without increasing blood viscosity or volume (Wayne, Kevy and Nathan, Blood 1993; 81:1109-1123). Hemoglobin electrophoresis may be used to monitor the effectiveness of the exchange in decreasing HbS. The post-exchange HbS electrophoresis results which were obtained in this case initially caused confusion. In this report we discuss the findings and the reasons why such results may be occasionally expected in future similar situations.