Evaluation of a competitive hepcidin ELISA assay in the differential diagnosis of iron deficiency anaemia with concurrent inflammation and anaemia of inflammation in elderly patients

In this study, a competitive hepcidin ELISA assay was evaluated for its ability to differentiate between iron deficiency anaemia with concurrent inflammation and anaemia of inflammation in elderly patients, using the absence of stainable bone marrow iron as the diagnostic criterion for iron deficiency. In addition, correlation coefficients for hepcidin versus C-reactive protein, ferritin and interleukin-6 were determined. The optimal cut-off for hepcidin was 21 μg/L, corresponding to sensitivity and specificity of 100% and 67%, respectively, for iron deficiency. For ferritin, a sensitivity and specificity of 91% and 83%, respectively, correspond to an optimal cut-off of 87 μg/L. Receiver operating characteristics curve analysis revealed that ELISA analysis of hepcidin is not superior to ferritin in the diagnosis of iron deficiency in elderly anaemic patients with concurrent inflammation. Hepcidin shows a strong positive correlation with ferritin, and also correlates positively with C-reactive protein in this patient population.