The usefulness of the ferritin and soluble transferrin receptor /(log)ferritin index in identifying iron deficiency among blood donors

Abstract

Objective: To evaluate whether screening donors for red cell and iron indices before donation are useful in identifying donors with iron deficiency  

Methods: The Hb, red cell indices, serum ferritin (s-ferritin), soluble transferrin receptor (sTfR), and the sTfR/(log)ferritin (sTfR-F) index were measured. Diagnostic efficiencies of the sTfR / log ferritin index (sTfR / F) and s-ferritin were evaluated by receiver operating characteristic curve (ROC) analysis. The Youden index was used to determine the cutoff levels.

Result: About 4.4% and 67.8% had reduced iron stores when classified as sferritin <15 ng/dL and  sTfR ratio/Log ferritin value <1.7 respectively. Increased frequency of blood donation leads to reduced iron stores, OR 16.8 (95%CI: 1.63– 174.68 p = 0.02).  The area-under-the-curve (AUC) for ferritin was 0.98, with 13.57 as cut-off, sensitivity, and specificity of 100% and 89.7%, respectively. The AUC for sTfR/F  was 0.97, with a cut-off of 1.0, the sensitivity of 100%, and the specificity of 94%.

Conclusions: The sTfR/log ferritin index (sTfR/F) is better than s-ferritin  in detecting reduced iron stores. There is a need to screen beyond levels using sFerritin or sTfR/log ferritin index (sTfR/F) in both new and repeat blood  donors to identify those with reduced iron stores