Early detection of iron deficiency in elite athletes: could microcytic anemia factor (Maf) be useful?

Background: The aim of this study was to establish the sensitivity and specificity of the microcytic anemia factor (Maf(®)), which is generated by the Coulter LH 750 analyzer in the evaluation of iron depletion and iron-deficient erythropoiesis in athletes.

Methods: A total of 142 athletes were divided into three groups: with iron depletion, with iron-deficient erythropoiesis, and controls. The following parameters were measured: RBCs (red blood cells), Hb (hemoglobin), Hct (hematocrit), MCV (mean cellular volume), MCH (mean cell hemoglobin), MCHC (mean cell hemoglobin corpuscular), RDW (red cell distribution width), Maf(®), Reticulocytes, Ferritin, sTfR (soluble transferrin receptor), Transferrin, Haptoglobin, IL- 6 (Interleukin-6), hs-CRP (high-sensitivity C-reactive protein).

Results: The best Maf(®) value to exclude iron depletion in athletes was 130.3, showing a sensitivity of 72.6% and a specificity of 57.3%. The AUC was 0.690 (CI 95% 0.607-0.765, P < 0.001). ROC curve analysis for Maf(®) in the diagnosis of iron-deficient erythropoiesis indicates sensitivity of 61.5%, and specificity of 93.0%, with AUC = 0.826 (CI 95% 0.754-0.885, P < 0.001) and on cutoff value 114.

Conclusions: This study shows that Maf(®) generated by the Coulter LH 700 Series hematology analyzers, performs very well in discriminating healthy athletes and those with different stages of iron deficiency. Also, in cost/benefit terms, monitoring of Maf(®) is justified as a low cost, effective screening parameter for determining iron status in athletes.