Preliminary assessment of the new Sysmex XN parameter Iron-Def for identifying iron deficiency

Abstract

Background - Although the clinical assessment of iron status is usually based on iron stores, a rapid and accurate diagnosis of iron deficiency is challenging since ferritin is often unavailable as an urgent test and its value is frequently increased in acute phase conditions. This study was therefore aimed at evaluating the diagnostic performance of the new Sysmex XN “Iron Deficiency?” (Iron-Def) parameter for identifying patients with iron deficiency.
Materials and methods - The study population consisted of 688 consecutive patients (median age: 71 years; 341 women and 347 men), referred for routine diagnostics to the Laboratory of Clinical Pathology of Lecco Hospital, Italy. A complete clinical chemistry profile and haematological testing were performed for identifying iron deficiency anaemia.
Results - A significant negative correlation was found between Sysmex XN Iron-Def and ferritin, serum iron, mean cell haemoglobin concentration, mean cell haemoglobin, mean corpuscular volume and age, while a positive correlation was noted with transferrin, percentage of microcytic red cell, red blood cell count and red blood cell distribution width. The diagnostic accuracy of Iron-Def for identifying patients with a percentage of saturation of transferrin <15% (n=104) was 84%, with a sensitivity of 0.952 and specificity of 0.538. A sub-analysis of 71 patients with ferritin <20 ng/dL yielded an even better diagnostic performance (86%, with a sensitivity of 0.935 and specificity of 0.620).
Discussion - Although additional confirmatory investigations would be needed, the preliminary findings of our study attest that Iron-Def may be an easy, inexpensive, rapid and reliable parameter for screening iron deficiency anaemia.