From the Guidelines
The laboratory findings of normal Total Iron-Binding Capacity (TIBC), normal Unbound Iron-Binding Capacity (UIBC), normal iron saturation, elevated iron level, and low ferritin level suggest a state of iron overload with depleted iron stores, which is a paradoxical condition that may be seen in cases of functional iron deficiency or inflammatory iron block. This pattern indicates that despite normal circulating iron levels and normal iron saturation, the body's iron stores are depleted, as reflected by the low ferritin level. According to the most recent guidelines from the British Society of Gastroenterology 1, a serum ferritin level of <15 μg/L is highly specific for iron deficiency. The normal TIBC and UIBC levels suggest that the iron-binding capacity is not affected, and the elevated iron level may be due to increased iron absorption or release from stores. However, the low ferritin level indicates that the iron stores are depleted, which may be due to various causes such as blood loss, malabsorption, or dietary insufficiency. It is essential to investigate the potential causes of iron deficiency and consider oral iron supplementation to replenish iron stores. I recommend starting oral iron supplementation, typically ferrous sulfate 325 mg once or twice daily, taken on an empty stomach with vitamin C to enhance absorption, and continue supplementation for 3-6 months to replenish iron stores, with follow-up testing of ferritin levels after 2-3 months. Additionally, it is crucial to monitor the patient's response to treatment and adjust the supplementation regimen as needed to avoid iron overload. The guidelines from the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) 1 also emphasize the importance of distinguishing between absolute and functional iron deficiency in patients with chronic kidney disease. In this case, the patient's laboratory findings suggest a state of functional iron deficiency, which may require a different approach to treatment. Overall, the management of this patient's condition requires a comprehensive approach that takes into account the complex interplay between iron metabolism, inflammation, and kidney function.