A Flow Cytometric Method of Determining CD71+ Erythroid Cells in Neonatal Whole Blood

The neonatal immune system exhibits a unique composition and function, rendering neonates particularly susceptible to infections and inflammatory conditions such as necrotizing enterocolitis (NEC). A distinct feature of neonatal immunity is the abundance of CD71⁺ erythroid cells (CECs), which are significantly more prevalent in neonates than in adults and possess immunosuppressive properties that can modulate neonatal immune responses. However, their quantification and functional analysis have been challenging given the small volume of blood typically available for assessment.. In this study, we present a comprehensive 24-color flow cytometry panel optimized to detect and quantify CD71⁺CD235a⁺ cells in minimal volumes of neonatal whole blood. This panel enables precise enumeration of CECs and detailed characterization of other key immune cell subsets, including T cells, monocytes, and natural killer cells. Additionally, our method allows for the functional assessment of CECs, such as evaluating Arginase 2 levels, to better understand their immunomodulatory roles. This approach provides a robust tool for dissecting the neonatal immune landscape and offers valuable insights into how CECs may impact other immune populations. Ultimately, this approach lays the groundwork for further research into the mechanisms behind neonatal vulnerability to infections and inflammation, potentially guiding the development of targeted therapeutic strategies.