Going beyond iron studies for iron deficiency anaemia: new cellular biomarkers for diagnosis

The full blood count is one of the simplest and most ordered blood investigations in daily practice. Its use and that of other classic markers for iron deficiency have been well established. Recently, there has been increased attention to the potential for fluorescence flow cytometry as an enhancement to the classic blood count. This paper explores the potential of new cellular biomarkers using this technology to enhance our diagnosis of iron deficiency anaemia (IDA) and differentiate between sepsis and systemic inflammation. For IDA, parameters such as the reticulocyte haemoglobin equivalent (RET-He) and the difference between reticulocyte and erythrocyte haemoglobin equivalent (DELTA-He) are exciting additions to enhance the speed and accuracy of its diagnosis. RET-He, which is defined as the haemoglobin content in reticulocytes, offers a more immediate reflection of iron availability for erythropoiesis compared to traditional markers such Hb concentration and mean corpuscular volume. The integration of advanced technologies, such as fluorescence flow cytometry, into routine blood counts can significantly improve diagnostic precision, allowing for a more nuanced understanding of the haematopoietic system and immune response. In critically ill patients, these new parameters can help to differentiate between various inflammatory responses and infections, providing valuable insights into the activation status of neutrophils and other immune cells. Parameters such as immature granulocytes and neutrophil reactivity intensity have shown promise in discriminating between systemic inflammatory response syndrome and sepsis. The introduction of these markers holds the potential for quicker and more cost-effective assessments for sepsis. The addition of fluorescence flow cytometry parameters to our armament of investigations for blood counts could enhance our abilities to practice precision medicine.