Effects of Iron Deficiency and Its Indicators on Lymphocyte Subsets: A Study at King Fahd Hospital of the University, Saudi Arabia

BACKGROUND: Iron deficiency plays an important role in our body’s immunity. Several studies have shown that it is frequently associated with infections. OBJECTIVE: This study aimed to discover the effect of iron deficiency on immunity by demonstrating changes occurring in lymphocyte subsets among patients with an established diagnosis of iron deficiency. METHODS: A total of 64 iron-deficient patients and 19 healthy controls were included. Complete blood counts, serum iron, ferritin, and total iron-binding capacity were assessed. Lymphocyte subsets were evaluated by flow cytometry. RESULTS: Among iron-deficient patients, the anemic ones (Hb ≤11 g/dL) showed significantly lower absolute lymphocyte counts (p=0.013), lower relative and absolute NK-cell counts (p=0.025 and p=0.003, respectively), higher relative T-cell and CD4(+)-cell counts (p=0.026 and p=0.002, respectively). B cells and CD8(+) T cells were not affected by any iron-deficiency indicators. Iron-deficient anemia patients showed a three- to fourfold increase in risk of having recurrent infections. CONCLUSION: Iron deficiency has an obvious effect on lymphocyte subsets. Changes in lymphocyte subsets started mainly in response to decreased hemoglobin, rather than decreased ferritin and/or iron. Synchronously decreased hemoglobin and increased total iron-binding capacity led to absolute decreases in total lymphocytes, mainly NK cells, and relative increases in T cells, mainly the helper ones. Monitoring changes in lymphocyte subsets may be helpful in identifying patients at risk of recurrent infections.