Clinical usefulness of the reticulocyte hemoglobin equivalent in children on hemodialysis.

Abstract

Iron-deficiency anemia is common in hemodialysis patients. Serum ferritin and transferrin saturation (TS) are used for its detection. The reticulocyte hemoglobin equivalent (RET-He) is a marker that is not altered by inflammatory conditions and directly reflects iron availability in the bone marrow. To explore the diagnostic capability of RET-He to detect absolute iron deficiency and assess its correlation with traditional markers of iron deficiency. Retrospective study comparing RET-He with ferritin and TS in children on hemodialysis seen at Hospital Garrahan between July 2016 and July 2019. In 164 observations carried out in 40 children, a weak positive correlation was found between hemoglobin and RETHe (r = 0.35, p < 0.001), a significant positive correlation between TS and RET-He (r = 0.52, p < 0.001), a low negative correlation between hemoglobin and ferritin (r = -0.19, p = 0.02), and a lack of correlation between hemoglobin and TS (r = 0.05, p = 0.5). Anemia was observed in 50 %; iron-deficiency anemia was detected by traditional markers in 13 % and by RET-He in 44 %. RET-He showed a sensitivity of 90.9 % (95 % CI: 57.1-99.5 %), a specificity of 74.5 % (95 % CI: 66.7-81 %), a negative predictive value of 99.1 % (95 % CI: 94.5-99.9 %), and a positive predictive value of 20.4 % (95 % CI: 10.7-34.7 %) to detect iron-deficiency anemia with a cut-off value of 29 pg. Despite its limited capability, the use of RET-He as a biomarker of iron deficiency increases the detection of iron-deficiency anemia in children on hemodialysis.