Iron metabolism and peripheral eosinophil count do not correlate in the general population

Iron is a primary component of the human body and exerts many functions, mainly concerning red cells and the immune system. In addition, there is evidence that iron-deficiency anemia is associated with allergic diseases. Type 2 inflammation characterizes allergic diseases. Peripheral eosinophils are a reliable biomarker for type 2 inflammation. Therefore, the present study investigated the possible relationship between iron metabolism and peripheral eosinophils in a large population. Eosinophils also play important roles in immune and tissue homeostasis. A growing body of data suggests tissue eosinophils represent a plastic and heterogeneous population of functional sub-phenotypes, shaped by environmental (systemic and local) factors. The retrospective study included 2,795 subjects who were afferent to the Clinical Chemistry Analysis Laboratory during the year 2022. Men had higher peripheral eosinophil count than women (p<0.001). Furthermore, stratifications for sex, eosinophil, and hemoglobin cut-offs showed that men had more eosinophil counts than women. However, there was no correlation between iron biomarkers and peripheral eosinophils. The present study did not demonstrate a clear relationship between iron deficiency and peripheral eosinophil count. Even if this large population may include allergic subjects and patients with different diseases, it seems that iron does not directly affect eosinophil count.