Regular transfusion lowers plasma free hemoglobin in children with sickle-cell disease at risk for stroke.
OBJECTIVE
Intravascular hemolysis releases large amounts of free hemoglobin (PFH) in plasma of sickle-cell disease (SCD) patients. PFH has been associated with harmful endothelial actions including scavenging nitric oxide (NO). Whether PFH plays a role in stroke in SCD has not been examined.


METHODS
Serum levels of PFH, lactate dehydrogenase, and total bilirubin were measured in stored sera from children at risk for stroke treated in a randomized controlled trial of regular red cell transfusion (STOP study). Baseline and post-treatment (approximately 1 year of transfusion) were compared to determine whether treatment (which reduces stroke risk by 90%) was associated with reduction in markers of hemolysis.


RESULTS
Baseline serum PFH values did not differ between treatment groups. PFH declined with repeated transfusion from 78.7+/-8.2 mg/dL to 34.4+/-3.4 mg/dL (P<0.001). With only episodic or no transfusion the drop was smaller: 80.9+/-7.5 to 62.8+/-5.0 (P=0.019). The decrease was larger in those with regular transfusion (56% versus 22%; P<0.001). Reduction of lactate dehydrogenase and total bilirubin was observed only in those on regular transfusion.


CONCLUSIONS
Regular transfusion which lowers stroke risk is associated with a significant reduction in PFH. A role for PFH in promoting stroke in SCD should be investigated.
Lezcano
Nelson E
NE
Department of Neurology, School of Medicine, Medical College of Georgia, Augusta, GA 30912, USA.
Odo
Nadine
N
Kutlar
Abdullah
A
Brambilla
Donald
D
Adams
Robert J
RJ
D000755:Anemia, Sickle Cell / Q000097:blood* / Q000150:complications / Q000628:therapy*; D001663:Bilirubin / Q000097:blood; D001803:Blood Transfusion; D002648:Child; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D012307:Risk Factors; D020521:Stroke / Q000209:etiology
D006454:Hemoglobins; D007770:L-Lactate Dehydrogenase; D001663:Bilirubin