Utility of soluble transferrin receptor measurement for early diagnostic of iron deficiency in elderly hospitalized patients

Diagnosis of iron deficiency is not easily performed in inflammatory situation as usually encountered in elderly hospitalized patients (>70 years old). At first, we determined serum soluble receptor transferrin (RsTf), RsTf/serum ferritin ratio (RsTf-F index) and biochemical and haematological values used to evaluate iron status, in iron-depleted subjects (ferritinemia≤50 μg/L) (group 2) (n=22, 82±7 years) or not (group 1, reference group) (n=18, 82±6 years), without inflammatory diseases. Relevance of the biological parameters to diagnose iron deficiency was evaluated (ROC curve) and a cut-off value of RsTf-F (>1.85) was established. Then, we selected 60 patients (group 3) suspect of iron deficiency as previously validated with an inflammatory syndrome (CRP>12 mg/L). Almost all patients (95%) presented at least one risk factor of iron deficiency (anticoagulant drugs, nutritional or gastrointestinal diseases). In group 3, index RsTf-F values were increased (RsTf-F: 2.69±0.82 versus group 1: 1.25±0.34, p