Hemoglobin-oxygen affinity changes in neonatal blood transfusions: RBC selection insights

Background

Despite preterm newborns often requiring blood transfusions, we have an incomplete understanding of the impact of adult packed red blood cell (pRBC) transfusions on fetal red blood cell (RBC) oxygen affinity. We investigated the influence of adult pRBC on oxygen binding in fetal RBCs obtained from the umbilical cord of preterm newborns. This included exploring the influence of the biological age of adult pRBCs on the oxygen affinity of fetal blood.

Methods

Cord blood samples from preterm infants were titrated with young (Y-RBC) and old (O-RBC) adult pRBCs using an in vitro transfusion model. Parameters, including oxygen affinity (p50), hemoglobin variants, and red blood cell indices, were measured.

Results

The titration of cord blood with adult pRBCs (n = 19) resulted in a concentration-dependent decrease in p50, indicating an increased oxygen affinity. Hemoglobin variant analysis revealed a shift in composition, with a decrease in fetal hemoglobin (HbF) and an increase in adult hemoglobin (HbA) following titration.

Conclusion

The impact of biological age was evident, as O-RBCs had a more pronounced effect on p50 values compared to Y-RBCs. Understanding the physiologic implications of transfusing preterm infants with adult pRBCs is important for optimizing transfusion practices in newborns.

Impact

In an in vitro model, titrating adult pRBC into fetal blood significantly affects oxygen binding

Oxygen affinity of fetal blood is significantly increased after titration of adult pRBC.

Compared to older RBC subpopulations of adult pRBC, oxygen-binding properties of younger RBC subpopulations of adult pRBC more closely approximate the oxygen affinity of fetal blood.

This work highlights the importance of investigating the influence of adult pRBC transfusion on fetal RBC oxygen binding.

This may have implications for morbidities in the newborn period related to oxygen physiology.