Importance of the reticulocyte hemoglobin equivalent in the exclusion of latent iron deficiency.

Background: Iron deficiency is an underdiagnosed public health problem, especially in developing countries, that can conceal serious underlying illnesses. Early diagnosis and treatment of latent iron deficiency (LID) is crucial. Reticulocyte hemoglobin equivalent (RET-He), was reported to be a cost-effective tool that reflects the iron availability at erythropoiesis. The aims of this study were to evaluate the RET-He in the exclusion of LID.

Methods: Transversal study was carried out in the laboratory of clinical biology of Ben Arous regional hospital, it included volunteers in apparently good health. We performed a complete blood count and a serum ferritin assay. Participants with normal hemoglobin were divided into two groups: Control group G1: normal ferritin (≥ 15 ng/mL)/LID group G2: low ferritin (< 15 ng/mL). We compared the blood count parameters of the two groups.

Results: We selected 108 participants (G1: 88 (81.5%), G2: 20 (18.5%)), mean age = 36 years, gender-ratio = 0.92. We noted, in G2, significantly lower rates for hemoglobin Hb (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin MCH (p = 0.026), reticulocyte count (p = 0.039) and RET-He (p < 0.001) and significantly higher rate for RDW/CV (p = 0.009). RET-He averages were 29.1 pg in G2 and 31.1pg in G1. In multivariate analysis, only RET-He showed a significant difference between the two groups. Area under the curve was 0.872, the cutoff = 30.9 (sensitivity 100%, specificity 61%, PPV 37%, NPV 100%).

Conclusion: RET-He is an accessible and affordable parameter of the iron status, with an excellent NPV. It would be interesting to evaluate our results on a larger sample to define reference values in our population.