Production of red blood cell units from umbilical cord blood for autologous transfusion of preterm neonates : An evaluation of storage time and storage medium on hemolysis and immunosuppressive effect

Abstract

BACKGROUND: In the weeks following birth, preterm infants often develop anemia requiring blood transfusions. The aims of the study were to examine the quality of red blood cell (RBC) units from cord blood (CB) during 5 weeks of storage, to compare two different storage media and to examine the releases of immunosuppressive substances during storage. MATERIAL AND METHODS: We collected CB from healthy, term neonates born by Caesarean section. The CB was collected in 150 ml storage-containers using CPD (citrate-phosphate-dextrose) as anti-coagulant. The blood was centrifuged, plasma was expressed and either SAG-M (saline, adenine, glucose and mannitol) or PAGGS-M (phosphate, adenine, glucose, guanosine, saline and mannitol) was added as preservation solution. All units (19 SAG-M and 15 PAGGS-M) were stored for 35 days at 4 C. Samples collected the production date and every week, were examined for hemolysis and supernatants from the samples were stored at -20 C. The release of immunosuppressive substances was examined as follows: Freshly heparinized CB was incubated with 10 % volume of supernatant from CB (11 SAG-M and 11 PAGGS-M units) and 50 ng/ml LPS (lipopolysaccharide) toxin. After 6 hours at 37 C, these saples were centrifuged and the amount of TNF-alfa was subsequently assessed by ELISA. RESULTS: Mean blood volume collected was 89.6 ml. During the 5 weeks there was a significant increase in hemolysis (p<0.01), in PAGGS-M significantly less than in SAG-M during the first 4 weeks (p<0.05). The LPS-induced TNF-alfa production decreased with increasing storage time of the CB units from which the supernatants was harvested, but the TNF-alfa production did not differ between the storage media.