Reticulocyte Hemoglobin Equivalent: Diagnostic Performance in Assessment of Iron Deficiency in Patients with Hypothyroidism

Reticulocyte hemoglobin content associated with the risk of iron deficiency anemia

Background/Objective

Reticulocyte hemoglobin content (MCHr) was recognized as a rapid and reliable marker for investigating iron deficiency (ID). We hypothesized that MCHr was associated with the risk of iron deficiency anemia in adults.

Methods

This is a dual-center case-control study. A total of 806 patients and healthy individuals were recruited from Ruijin Hospital and Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine between January 2021 and December 2021. The participants were categorized into iron deficiency anemia (IDA) group (n = 302), non-IDA group (n = 366), and healthy control group (n = 138). According to the MCHr level, the participants were divided into two groups, i.e. normal MCHr (≥25 pg) and decreased MCHr (<25 pg) group. Multivariate logistic regression analysis and adjusted subgroup analysis were conducted to estimate the relative risk between MCHr and IDA, with confounding factors including age, sex, hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), Hematocrit (HCT), serum iron (Fe), ferritin (Ferrit), and total iron binding capacity (TIBC).

Results

Compared with the non-IDA, the MCHr level with IDA decreased significantly. ROC curve analysis showed that MCHr had the largest area under the AUC curve. After comprehensive adjustment for confounding factors, individuals with normal level of MCHr exhibited a decreased risk of IDA (OR = 0.68 [0.60, 0.77], P < 0.01), while the risk of IDA was up to 5 times higher for those with decreased MCHr.

Conclusion

Our findings supported the hypothesis that MCHr was associated with the risk of IDA in adults and could serve as an indicator of IDA severity. MCHr holds clinical value as an auxiliary diagnostic indicator, providing valuable insights into whether invasive examinations are warranted in the assessment of IDA.

The association of hepcidin, reticulocyte hemoglobin equivalent and anemia-related indicators on anemia in chronic kidney disease

Hepcidin is an essential regulator of iron homeostasis in chronic kidney disease (CKD) anemia, reticulocyte hemoglobin equivalent (RET-He) can be used to evaluate the availability of iron for erythropoiesis. Previous research has found that hepcidin indirectly regulates RET-He. This study aimed to investigate the association of hepcidin, RET-He and anemia-related indicators on anemia in chronic kidney disease. A total of 230 individuals were recruited, including 40 CKD3-4 patients, 70 CKD5 patients without renal replacement therapy, 50 peritoneal dialysis patients, and 70 hemodialysis patients. The serum levels of hemoglobin (Hb), reticulocyte, RET-He, serum iron, serum creatinine, serum ferritin, total iron binding capacity, hepcidin-25, high sensitivity C-reactive protein, transferrin, erythropoietin, intrinsic factor antibody, soluble transferrin receptor and interleukins-6 (IL-6) were measured. Hepcidin-25 was positively associated with IL-6, and negatively with total iron binding capacity, intrinsic factor antibody, and transferrin. Reticulocyte Hb equivalent was associated positively with Hb, serum ferritin, serum iron, transferrin saturation, and negatively with serum creatinine, reticulocyte, IL-6, STfR. Hepcidin-25 was not associated with RET-He, while IL-6 was independently associated with hepcidin-25 and RET-He, suggesting that hepcidin has no effffect on the iron dynamics of reticulocytes in CKD, may be related to IL-6, indicate a likelihood of a threshold for stimulation of hepcidin-25 expression by IL-6 in order to indirectly regulates RET-He.

Implementing Reticulocyte Hemoglobin Into Current Hematology Algorithms

OBJECTIVES

This systematic review investigates reticulocyte hemoglobin's capabilities in screening iron deficiency and iron-deficiency anemia with and without comorbidities.

METHODS

Participant background and laboratory characteristics were extracted from 14 unique studies between 2015 and 2022. Hemoglobin, reticulocyte hemoglobin, and mean cell volume (MCV) values were used in a meta-analysis for iron-deficiency anemia with no secondary conditions. Mean laboratory values for each patient population were calculated and then used to determine sensitivity, specificity, and the area under the curve (AUC) for iron deficiency and iron-deficiency anemia. The ferritin and reticulocyte hemoglobin ranges were calculated using the mean values.

RESULTS

The meta-analysis demonstrates that hemoglobin and MCV values do not significantly differ between studies, unlike reticulocyte hemoglobin values. The reticulocyte hemoglobin range is smaller than ferritin for the controls, iron deficiency, and iron-deficiency anemia. Reticulocyte hemoglobin values less than 26 pg can distinguish iron-deficiency anemia, while 26 to 31.5 pg can distinguish iron deficiency, with an AUC of 0.889. The sensitivity and specificity are 92.3% and 100% for iron-deficiency anemia, 100% and 81.5% for iron deficiency, and 94.4% and 71.4% for both, respectively (reference range, <31.5 pg).

CONCLUSIONS

Reticulocyte hemoglobin is potentially a quick screening test for iron deficiency and iron-deficiency anemia.