Exploring the use of expanded erythroid cells for autologous transfusion for anemia of prematurity.

BACKGROUND: Autologous cord blood (CB) red blood cells (RBCs) can partly substitute transfusion needs in premature infants suffering from anemia. To explore whether expanded CB cells could provide additional autologous cells suitable for transfusion, we set up a simple one-step protocol to expand premature CB cells. STUDY DESIGN AND METHODS: CB buffy coat cells and isolated CD34-positive (CD34(pos) ) cells from premature and full-term CB and adult blood were tested with several combinations of growth factors while omitting xenogeneic proteins from the culture medium. Cell differentiation was analyzed serially during 21 days using flow cytometry, progenitor assays, and high-performance liquid chromatography. RESULTS: Expanded CB buffy coat cells resulted in a threefold higher number of erythroblasts than the isolated CD34(pos) cells. However, the RBCs contaminating the buffy coat remained present during the culture with uncertain quality. Premature and full-term CB CD34(pos) cells had similar fold expansion capacity and erythroid differentiation. With the use of interleukin-3, stem cell factor, and erythropoietin, the fold increases of all CD34(pos) cell sources were similar: CB 3942 ± 1554, adult peripheral mobilized blood 4702 ± 1826, and bone marrow (BM) 4143 ± 1908. The proportion of CD235a expression indicating erythroblast presence on Day 21 was slightly higher in the adult CD34(pos) cell sources: peripheral blood stem cells (96.7 ± 0.8%) and BM (98.9 ± 0.5%) compared to CB (87.7 ± 2.7%; p = 0.002). We were not able to induce further erythroid maturation in vitro. CONCLUSION: This explorative study showed that fairly pure autologous erythroid-expanded cell populations could be obtained by a simple culture method, which should be optimized. Future challenges comprise obtaining ex vivo enucleation of RBCs with the use of a minimal manipulating approach, which can add up to autologous RBCs derived from CB in the treatment of anemia of prematurity.

Long-term outcome in relationship to neonatal transfusion volume in extremely premature infants: a comparative cohort study.

BACKGROUND: In premature born infants red blood cell (RBC) transfusions have been associated with both beneficial and detrimental sequels. Upon RBC transfusion, improvement in cerebral blood flow and oxygenation have been observed, while a more liberal transfusion policy may be associated with a better developmental outcome. The effect of the transfusion volume on long-term outcome is not known. METHODS: Observational follow-up study of a cohort of extremely premature born infants, treated in 2 neonatal intensive care units using a different transfusion volume (15 ml/kg in Unit A and 20 ml/kg in Unit B). The primary outcome was a composite of post discharge mortality, neuromotor developmental delay, blindness or deafness, evaluated at a mean corrected age (CA) of 24 months related to the transfusion volume/kg bodyweight administered during the postnatal hospital stay. RESULTS: Despite the difference in transfusion volume in clinically comparable groups of infants, they received a similar number of transfusions (5.5 ± 3.2 versus 5.5 ± 2.3 respectively in Unit A and B). The total transfused volume in unit A was 79 ± 47 ml/kg and 108 ± 47 ml/kg in unit B (p = 0.02). Total transfused RBC volume per kg bodyweight was not an independent predictor of the composite outcome (p = 0.96, OR 1.0 (CI 0.9-1.1). CONCLUSION: There was no relationship between the composite outcome at 24 months CA and transfusion volume received during the post natal hospital stay. As there was no clinical advantage of the higher transfusion volume, a more restrictive volume will reduce total transfusion volume and donor exposure. Future research on the optimal transfusion volume per event to extreme preterm infants should include larger, prospective studies with a longer follow-up period through to childhood or even adolescence.

A clinical study on the feasibility of autologous cord blood transfusion for anemia of prematurity.

BACKGROUND: The objective was to investigate the use of autologous red blood cells (RBCs) derived from umbilical cord blood (UCB), as an alternative for allogeneic transfusions in premature infants admitted to a tertiary neonatal center. STUDY DESIGN AND METHODS: UCB collection was performed at deliveries of less than 32 weeks of gestation and processed into autologous RBC products. Premature infants requiring a RBC transfusion were randomly assigned to an autologous or allogeneic product. The primary endpoint was an at least 50 percent reduction in allogeneic transfusion needs. RESULTS: Fifty-seven percent of the collections harvested enough volume (> or =15 mL) for processing. After being processed, autologous products (> or =10 mL/kg) were available for 36 percent of the total study population and for 27 percent of the transfused infants and could cover 58 percent (range, 25%-100%) of the transfusion needs within the 21-day product shelf life. Availability of autologous products depended most on the gestational age. Infants born between 24 and 28 weeks had the lowest availability (17%). All products, however, would be useful in view of their high (87%) transfusion needs. Availability was highest (48%) for the infants born between 28 and 30 weeks. For 42 percent of the infants with transfusion needs in this group, autologous products were available. For the infants born between 30 and 32 weeks, autologous products were available for 36 percent of the infants. Transfusion needs in this group were, however, much lower (19%) compared to the other gestational groups. CONCLUSION: Autologous RBCs derived from UCB could not replace 50 percent of allogeneic transfusions due to the low UCB volumes collected and subsequent low product availability.